Merge branch 'master' of https://git.steakelectronics.com/adminguy/Electronics_Projects_2019

ok

Car_Stereo_Replacement/bom/amp/bom1

@@ -0,0 +1,3 @@
+PTV09A-2020F-A104-ND  - logarithmic horizontal pot 100k
+
+LA6500-EOS-ND - generic power op amp

Car_Stereo_Replacement/docs/10.aux

@@ -0,0 +1,15 @@
+\relax 
+\@writefile{toc}{\contentsline {section}{\numberline {1}Overview}{1}}
+\@writefile{lof}{\contentsline {figure}{\numberline {1}{\ignorespaces PCB rev 1\relax }}{1}}
+\@writefile{toc}{\contentsline {section}{\numberline {2}Items Included}{1}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {2.1}I2C OLED display}{2}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {2.2}Internal AVR Temperature Sensor}{2}}
+\@writefile{toc}{\contentsline {section}{\numberline {3}Wiring Pinout is wrong on Internet - Cable has labels}{3}}
+\@writefile{toc}{\contentsline {section}{\numberline {4}Arduino VReg Blowout}{3}}
+\@writefile{toc}{\contentsline {section}{\numberline {5}Amplifier}{3}}
+\@writefile{toc}{\contentsline {section}{\numberline {6}AC Audio Coupling to Remove DC Noise from Auto}{3}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {6.1}Ground Isolator}{4}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {6.2}Capacitor Audio Coupling}{4}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {6.2.1}Impedance / ESR of capacitors failing to pass enough power of signal}{4}}
+\@writefile{lof}{\contentsline {figure}{\numberline {2}{\ignorespaces Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.\relax }}{5}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {6.2.2}Wikipedia on Impedance}{5}}

Car_Stereo_Replacement/docs/10.log

@@ -0,0 +1,237 @@
+This is pdfTeX, Version 3.14159265-2.6-1.40.17 (TeX Live 2016/Debian) (preloaded format=pdflatex 2019.8.17)  18 FEB 2020 23:04
+entering extended mode
+ restricted \write18 enabled.
+ %&-line parsing enabled.
+**/home/layoutdev/Desktop/code/documentation_general/Electronics_Projects_2019/
+Car_Stereo_Replacement/docs/10.tex
+
+(/home/layoutdev/Desktop/code/documentation_general/Electronics_Projects_2019/C
+ar_Stereo_Replacement/docs/10.tex
+LaTeX2e <2017/01/01> patch level 3
+Babel <3.9r> and hyphenation patterns for 3 language(s) loaded.
+(/usr/share/texlive/texmf-dist/tex/latex/base/article.cls
+Document Class: article 2014/09/29 v1.4h Standard LaTeX document class
+(/usr/share/texlive/texmf-dist/tex/latex/base/size11.clo
+File: size11.clo 2014/09/29 v1.4h Standard LaTeX file (size option)
+)
+\c@part=\count79
+\c@section=\count80
+\c@subsection=\count81
+\c@subsubsection=\count82
+\c@paragraph=\count83
+\c@subparagraph=\count84
+\c@figure=\count85
+\c@table=\count86
+\abovecaptionskip=\skip41
+\belowcaptionskip=\skip42
+\bibindent=\dimen102
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/graphicx.sty
+Package: graphicx 2014/10/28 v1.0g Enhanced LaTeX Graphics (DPC,SPQR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/keyval.sty
+Package: keyval 2014/10/28 v1.15 key=value parser (DPC)
+\KV@toks@=\toks14
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/graphics.sty
+Package: graphics 2016/10/09 v1.0u Standard LaTeX Graphics (DPC,SPQR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/trig.sty
+Package: trig 2016/01/03 v1.10 sin cos tan (DPC)
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics-cfg/graphics.cfg
+File: graphics.cfg 2016/06/04 v1.11 sample graphics configuration
+)
+Package graphics Info: Driver file: pdftex.def on input line 99.
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics-def/pdftex.def
+File: pdftex.def 2017/01/12 v0.06k Graphics/color for pdfTeX
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/infwarerr.sty
+Package: infwarerr 2016/05/16 v1.4 Providing info/warning/error messages (HO)
+)
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ltxcmds.sty
+Package: ltxcmds 2016/05/16 v1.23 LaTeX kernel commands for general use (HO)
+)
+\Gread@gobject=\count87
+))
+\Gin@req@height=\dimen103
+\Gin@req@width=\dimen104
+)
+(/usr/share/texlive/texmf-dist/tex/latex/caption/caption.sty
+Package: caption 2016/02/21 v3.3-144 Customizing captions (AR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/caption/caption3.sty
+Package: caption3 2016/05/22 v1.7-166 caption3 kernel (AR)
+Package caption3 Info: TeX engine: e-TeX on input line 67.
+\captionmargin=\dimen105
+\captionmargin@=\dimen106
+\captionwidth=\dimen107
+\caption@tempdima=\dimen108
+\caption@indent=\dimen109
+\caption@parindent=\dimen110
+\caption@hangindent=\dimen111
+)
+\c@ContinuedFloat=\count88
+) (./10.aux)
+\openout1 = `10.aux'.
+
+LaTeX Font Info:    Checking defaults for OML/cmm/m/it on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for T1/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OT1/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OMS/cmsy/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OMX/cmex/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for U/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+
+(/usr/share/texlive/texmf-dist/tex/context/base/mkii/supp-pdf.mkii
+[Loading MPS to PDF converter (version 2006.09.02).]
+\scratchcounter=\count89
+\scratchdimen=\dimen112
+\scratchbox=\box26
+\nofMPsegments=\count90
+\nofMParguments=\count91
+\everyMPshowfont=\toks15
+\MPscratchCnt=\count92
+\MPscratchDim=\dimen113
+\MPnumerator=\count93
+\makeMPintoPDFobject=\count94
+\everyMPtoPDFconversion=\toks16
+) (/usr/share/texlive/texmf-dist/tex/generic/oberdiek/pdftexcmds.sty
+Package: pdftexcmds 2016/05/21 v0.22 Utility functions of pdfTeX for LuaTeX (HO
+)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ifluatex.sty
+Package: ifluatex 2016/05/16 v1.4 Provides the ifluatex switch (HO)
+Package ifluatex Info: LuaTeX not detected.
+)
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ifpdf.sty
+Package: ifpdf 2016/05/14 v3.1 Provides the ifpdf switch
+)
+Package pdftexcmds Info: LuaTeX not detected.
+Package pdftexcmds Info: \pdf@primitive is available.
+Package pdftexcmds Info: \pdf@ifprimitive is available.
+Package pdftexcmds Info: \pdfdraftmode found.
+)
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/epstopdf-base.sty
+Package: epstopdf-base 2016/05/15 v2.6 Base part for package epstopdf
+
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/grfext.sty
+Package: grfext 2016/05/16 v1.2 Manage graphics extensions (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/kvdefinekeys.sty
+Package: kvdefinekeys 2016/05/16 v1.4 Define keys (HO)
+))
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/kvoptions.sty
+Package: kvoptions 2016/05/16 v3.12 Key value format for package options (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/kvsetkeys.sty
+Package: kvsetkeys 2016/05/16 v1.17 Key value parser (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/etexcmds.sty
+Package: etexcmds 2016/05/16 v1.6 Avoid name clashes with e-TeX commands (HO)
+Package etexcmds Info: Could not find \expanded.
+(etexcmds)             That can mean that you are not using pdfTeX 1.50 or
+(etexcmds)             that some package has redefined \expanded.
+(etexcmds)             In the latter case, load this package earlier.
+)))
+Package epstopdf-base Info: Redefining graphics rule for `.eps' on input line 4
+38.
+Package grfext Info: Graphics extension search list:
+(grfext)             [.png,.pdf,.jpg,.mps,.jpeg,.jbig2,.jb2,.PNG,.PDF,.JPG,.JPE
+G,.JBIG2,.JB2,.eps]
+(grfext)             \AppendGraphicsExtensions on input line 456.
+
+(/usr/share/texlive/texmf-dist/tex/latex/latexconfig/epstopdf-sys.cfg
+File: epstopdf-sys.cfg 2010/07/13 v1.3 Configuration of (r)epstopdf for TeX Liv
+e
+))
+Package caption Info: Begin \AtBeginDocument code.
+Package caption Info: End \AtBeginDocument code.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <12> on input line 9.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <8> on input line 9.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <6> on input line 9.
+
+
+LaTeX Warning: No \author given.
+
+<../pics/DSCN2180.JPG, id=1, 803.0pt x 602.25pt>
+File: ../pics/DSCN2180.JPG Graphic file (type jpg)
+ <use ../pics/DSCN2180.JPG>
+Package pdftex.def Info: ../pics/DSCN2180.JPG used on input line 14.
+(pdftex.def)             Requested size: 321.1943pt x 240.89572pt.
+
+
+Package caption Warning: \captionsetup{type*=...} or \captionof
+(caption)                outside box or environment on input line 15.
+See the caption package documentation for explanation.
+
+LaTeX Font Info:    Try loading font information for OMS+cmr on input line 20.
+(/usr/share/texlive/texmf-dist/tex/latex/base/omscmr.fd
+File: omscmr.fd 2014/09/29 v2.5h Standard LaTeX font definitions
+)
+LaTeX Font Info:    Font shape `OMS/cmr/m/n' in size <10.95> not available
+(Font)              Font shape `OMS/cmsy/m/n' tried instead on input line 20.
+ [1
+
+{/var/lib/texmf/fonts/map/pdftex/updmap/pdftex.map} <../pics/DSCN2180.JPG>]
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <10.95> on input line 28.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <9> on input line 28.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <5> on input line 28.
+
+Underfull \hbox (badness 10000) in paragraph at lines 44--45
+[]\OT1/cmr/m/n/10.95 https://thecavepearlproject.org/2019/02/25/no-parts-temper
+ature-
+ []
+
+[2] [3] [4]
+<../pics/esr_impedance_capacitance.png, id=25, 697.10437pt x 421.69917pt>
+File: ../pics/esr_impedance_capacitance.png Graphic file (type png)
+
+<use ../pics/esr_impedance_capacitance.png>
+Package pdftex.def Info: ../pics/esr_impedance_capacitance.png used on input li
+ne 73.
+(pdftex.def)             Requested size: 348.55133pt x 210.84906pt.
+
+Overfull \hbox (13.6647pt too wide) in paragraph at lines 81--81
+[] \OT1/cmtt/m/n/10.95 https://en.wikipedia.org/w/index.php\title=Aluminum_elec
+trolytic 
+ []
+
+[5 <../pics/esr_impedance_capacitance.png (PNG copy)>] (./10.aux) ) 
+Here is how much of TeX's memory you used:
+ 2609 strings out of 494945
+ 41769 string characters out of 6181032
+ 96830 words of memory out of 5000000
+ 5894 multiletter control sequences out of 15000+600000
+ 10544 words of font info for 37 fonts, out of 8000000 for 9000
+ 14 hyphenation exceptions out of 8191
+ 39i,8n,39p,867b,195s stack positions out of 5000i,500n,10000p,200000b,80000s
+</usr/share/
+texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmbx10.pfb></usr/share/texliv
+e/texmf-dist/fonts/type1/public/amsfonts/cm/cmbx12.pfb></usr/share/texlive/texm
+f-dist/fonts/type1/public/amsfonts/cm/cmr10.pfb></usr/share/texlive/texmf-dist/
+fonts/type1/public/amsfonts/cm/cmr12.pfb></usr/share/texlive/texmf-dist/fonts/t
+ype1/public/amsfonts/cm/cmr6.pfb></usr/share/texlive/texmf-dist/fonts/type1/pub
+lic/amsfonts/cm/cmr8.pfb></usr/share/texlive/texmf-dist/fonts/type1/public/amsf
+onts/cm/cmr9.pfb></usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/
+cmsy10.pfb></usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmti10
+.pfb></usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmtt10.pfb>
+Output written on 10.pdf (5 pages, 376875 bytes).
+PDF statistics:
+ 62 PDF objects out of 1000 (max. 8388607)
+ 42 compressed objects within 1 object stream
+ 0 named destinations out of 1000 (max. 500000)
+ 11 words of extra memory for PDF output out of 10000 (max. 10000000)
+

Car_Stereo_Replacement/docs/10.tex

@@ -0,0 +1,87 @@
+\documentclass[11pt]{article}
+%Gummi|065|=)
+\title{\textbf{Car Stereo Replacement}}
+\usepackage{graphicx,caption}
+%\author{Steak Electronics}
+\date{02/13/20}
+\begin{document}
+
+\maketitle
+
+\section{Overview}
+Replacing a car stereo. I could just go to ebay, and buy a used car stereo, but where's the fun in that? Let's DIY a car stereo from a PCB used as a frontplate, a connector for my vehicle, and an audio amplifier. I'll connect in signal from an audio player.
+
+\includegraphics[scale=0.4]{../pics/DSCN2180.JPG}
+\captionof{figure}{PCB rev 1}
+
+\section{Items Included}
+I thought I would include the following:
+\begin{itemize}
+\item Arduino Nano
+\item Voltage and Gnd Breakout
+\item I2C Display
+\item Voltage Readout (of BAT)
+\item Current Readout (being drawn)
+\end{itemize}
+I also wanted to have the connectors that eurorack and synth designers use for mono audio cables, but the cables turned out too expensive. The current readout didn't work initially, and I haven't gotten to fixing it yet.
+\subsection{I2C OLED display}
+Just for fun, I bought an I2C oled display and am going to use it to display something.\footnote{It's an Arduino Uno, you can put almost anything on this.} Notes on this:
+Using the adafruit SSD1306 and GFX library (this procedure is well covered in other places), you can load an example sketch and get it running. First thing to change is to remove the Adafruit logo and replace it with my own. Let's do that.
+
+From https://design.goeszen.com/convert-image-for-oled-display.html
+\begin{verbatim}
+I'm on Linux here and found that the readily-available 
+ImageMagick package will do the trick for you without
+ any scripting. And runs on the CLI! Simple as that:
+
+    convert some_image.png some.image.mono
+\end{verbatim}
+That's efficient. But it didn't really work out. Too much work, I don't need it that bad. Have to convert it to something the c compiler can read. I instead, just deleted their logo. Good enough for now.
+\subsection{Internal AVR Temperature Sensor}
+
+I setup the code to read from the internal temp sensor on the duino. However there is also this:
+
+https://thecavepearlproject.org/2019/02/25/no-parts-temperature-measurement-with-arduino-pro-mini-to-0-005c-or-better/
+
+This would be something to do for more resolution. The built in sensor is not very good, so this above link would be great. Hack a day also covers it. 
+
+\section{Wiring Pinout is wrong on Internet - Cable has labels}
+I looked at the picture I have detailing the pinout of my car connector (Delco Delphi radio wiring diagram.jpg in resources). It's close, but not 100\% correct. I found that the cable itself has small text labels on each wire which explain which everything does. I didn't notice earlier, as I didn't look close enough (and no one mentioned this).
+
+\section{Arduino VReg Blowout}
+I had a knock off Arduino Nano, and the vreg blew out. I have some other vregs to replace it. I didn't have this problem with an Uno that I use as a ceiling dome light. Although that one is not left on as long, usually. 
+
+\section{Amplifier}
+The amplifier I used is one of the cheapest avialable on ebay. I'm not proud. I'm poor. I had to take it apart, and reseat the amplifier ICs as the tab was not making contact with the chassis for one of them. I also added thermal paste. This amp is underpowered for my car, and may need replacing. It gets a bit hot.
+
+Some other issues with this amplifier are that the output connectors can get pushed back, there is only one output connector option, and it must run on battery power, as a 12V 1A or 2A will not power it. Finally, there is a 6V DC bias on output. No output audio isolation, which means you get car noise.
+
+\section{AC Audio Coupling to Remove DC Noise from Auto}
+I had some fun with this one. Many videos on this in the video folder. I started with the speakers being directly fed by the amplifier. This worked, but there was some noise coming through. Cars are noisy, this is not surprising. I would've preferred the amplifier to isolate the outputs, but no luck... At this point, I considered two options to block DC and allow AC. 1) Use a transformer. 2) Use capacitors.\footnote{A third option would've been to use a second set of batteries, but that would be laborious.}
+
+\subsection{Ground Isolator}
+I had been given a Ground isolator, which was two small transformers on a pcb intended to pass audio from a car powered signal source into the car speakers. I tried this isolator on the output of the speakers, and while it worked, the volume was lower, and it was impractical. I knew as soon as I heard the volume, that the issue was an impedance matching problem. The transformers were too small. They were intended for signal sources, not amplifier outputs. Onto option \#2.
+
+\subsection{Capacitor Audio Coupling}
+My initial thoughts here were: ``Let's be careful and use non polarized caps''. I bought some 0.22uf and 0.022uf polyester film capacitors at Electronics Plus, the local radioshack replacement, and tried them. No sound. After adjusting the connectors on the amp (which were admittedly loose - it's easy to push them back on the amplifier if you are not careful) I found that the capacitors didn't work. One problem was evident in the oscope. I only used one capacitor on the + output of the speaker amp, but the Amp biases the signal 6 volts. So I needed two. After that was resolved, the signal came through on the output of the capacitor, as viewed on the scope, however there was no sound output. I tried the safe way. It's time to break some rules. 
+
+I grabbed some 1uf (electrolytic polarized) caps I had, and tried these. Again, no sound. Not giving up, I grabbed some 1000uf 'lytics, and tried once more. Now it worked.
+
+\subsubsection{Impedance / ESR of capacitors failing to pass enough power of signal}
+Capacitors are rated for impedance. Some data sheets also call this ESR, it appears after a quick look. It's either in there as impedance or ESR. It's not initially an issue if you are using the capacitor as a DC reservoir, but if you use it in an AC coupling situation then things get interesting. A high impedance, or ESR will block what a low one won't. In this example, it's as simple as the Amplfier either being able to power a speaker or not. Higher capacity caps will have lower impedance. See the picture. Other brands put impedance in a graph, or just call it impedance. 
+
+\includegraphics[scale=0.5]{../pics/esr_impedance_capacitance.png}
+\captionof{figure}{Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.}
+
+\subsubsection{Wikipedia on Impedance}
+
+\emph{In general, a capacitor is seen as a storage component for electric energy. But this is only one capacitor function. A capacitor can also act as an AC resistor. Especially aluminum electrolytic capacitors are used in many applications as a decoupling capacitors to filter or bypass undesired biased AC frequencies to the ground or for capacitive coupling of audio AC signals. Then the dielectric is used only for blocking DC. For such applications the AC resistance, the impedance is as important as the capacitance value. }
+\begin{verbatim} https://en.wikipedia.org/w/index.php\title=Aluminum_electrolytic
+_capacitor&oldid=940281525
+\end{verbatim}
+Essentially, what I learned today.
+
+
+
+
+\end{document}

Car_Stereo_Replacement/docs/11.aux

@@ -0,0 +1,19 @@
+\relax 
+\@writefile{toc}{\contentsline {section}{\numberline {1}Overview}{1}}
+\@writefile{lof}{\contentsline {figure}{\numberline {1}{\ignorespaces PCB rev 1\relax }}{1}}
+\@writefile{toc}{\contentsline {section}{\numberline {2}Items Included}{2}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {2.1}I2C OLED display}{2}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {2.2}Internal AVR Temperature Sensor}{2}}
+\@writefile{toc}{\contentsline {section}{\numberline {3}Wiring Pinout is wrong on Internet - Cable has labels}{3}}
+\@writefile{toc}{\contentsline {section}{\numberline {4}Arduino VReg Blowout}{3}}
+\@writefile{toc}{\contentsline {section}{\numberline {5}Amplifier}{3}}
+\@writefile{toc}{\contentsline {section}{\numberline {6}AC Audio Coupling to Remove DC Noise from Auto}{3}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {6.1}Ground Isolator}{4}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {6.2}Capacitor Audio Coupling}{4}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {6.2.1}Impedance / ESR of capacitors failing to pass enough power of signal}{4}}
+\citation{Scherz}
+\@writefile{lof}{\contentsline {figure}{\numberline {2}{\ignorespaces Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.\relax }}{5}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {6.2.2}Wikipedia on Impedance}{5}}
+\bibcite{Scherz}{1}
+\@writefile{toc}{\contentsline {section}{\numberline {7}DIY Amp}{6}}
+\@writefile{toc}{\contentsline {section}{\numberline {8}References}{6}}

Car_Stereo_Replacement/docs/11.log

@@ -0,0 +1,244 @@
+This is pdfTeX, Version 3.14159265-2.6-1.40.17 (TeX Live 2016/Debian) (preloaded format=pdflatex 2019.8.17)  18 FEB 2020 23:09
+entering extended mode
+ restricted \write18 enabled.
+ %&-line parsing enabled.
+**/home/layoutdev/Desktop/code/documentation_general/Electronics_Projects_2019/
+Car_Stereo_Replacement/docs/11.tex
+
+(/home/layoutdev/Desktop/code/documentation_general/Electronics_Projects_2019/C
+ar_Stereo_Replacement/docs/11.tex
+LaTeX2e <2017/01/01> patch level 3
+Babel <3.9r> and hyphenation patterns for 3 language(s) loaded.
+(/usr/share/texlive/texmf-dist/tex/latex/base/article.cls
+Document Class: article 2014/09/29 v1.4h Standard LaTeX document class
+(/usr/share/texlive/texmf-dist/tex/latex/base/size11.clo
+File: size11.clo 2014/09/29 v1.4h Standard LaTeX file (size option)
+)
+\c@part=\count79
+\c@section=\count80
+\c@subsection=\count81
+\c@subsubsection=\count82
+\c@paragraph=\count83
+\c@subparagraph=\count84
+\c@figure=\count85
+\c@table=\count86
+\abovecaptionskip=\skip41
+\belowcaptionskip=\skip42
+\bibindent=\dimen102
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/graphicx.sty
+Package: graphicx 2014/10/28 v1.0g Enhanced LaTeX Graphics (DPC,SPQR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/keyval.sty
+Package: keyval 2014/10/28 v1.15 key=value parser (DPC)
+\KV@toks@=\toks14
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/graphics.sty
+Package: graphics 2016/10/09 v1.0u Standard LaTeX Graphics (DPC,SPQR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/trig.sty
+Package: trig 2016/01/03 v1.10 sin cos tan (DPC)
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics-cfg/graphics.cfg
+File: graphics.cfg 2016/06/04 v1.11 sample graphics configuration
+)
+Package graphics Info: Driver file: pdftex.def on input line 99.
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics-def/pdftex.def
+File: pdftex.def 2017/01/12 v0.06k Graphics/color for pdfTeX
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/infwarerr.sty
+Package: infwarerr 2016/05/16 v1.4 Providing info/warning/error messages (HO)
+)
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ltxcmds.sty
+Package: ltxcmds 2016/05/16 v1.23 LaTeX kernel commands for general use (HO)
+)
+\Gread@gobject=\count87
+))
+\Gin@req@height=\dimen103
+\Gin@req@width=\dimen104
+)
+(/usr/share/texlive/texmf-dist/tex/latex/caption/caption.sty
+Package: caption 2016/02/21 v3.3-144 Customizing captions (AR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/caption/caption3.sty
+Package: caption3 2016/05/22 v1.7-166 caption3 kernel (AR)
+Package caption3 Info: TeX engine: e-TeX on input line 67.
+\captionmargin=\dimen105
+\captionmargin@=\dimen106
+\captionwidth=\dimen107
+\caption@tempdima=\dimen108
+\caption@indent=\dimen109
+\caption@parindent=\dimen110
+\caption@hangindent=\dimen111
+)
+\c@ContinuedFloat=\count88
+) (./11.aux)
+\openout1 = `11.aux'.
+
+LaTeX Font Info:    Checking defaults for OML/cmm/m/it on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for T1/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OT1/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OMS/cmsy/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OMX/cmex/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for U/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+
+(/usr/share/texlive/texmf-dist/tex/context/base/mkii/supp-pdf.mkii
+[Loading MPS to PDF converter (version 2006.09.02).]
+\scratchcounter=\count89
+\scratchdimen=\dimen112
+\scratchbox=\box26
+\nofMPsegments=\count90
+\nofMParguments=\count91
+\everyMPshowfont=\toks15
+\MPscratchCnt=\count92
+\MPscratchDim=\dimen113
+\MPnumerator=\count93
+\makeMPintoPDFobject=\count94
+\everyMPtoPDFconversion=\toks16
+) (/usr/share/texlive/texmf-dist/tex/generic/oberdiek/pdftexcmds.sty
+Package: pdftexcmds 2016/05/21 v0.22 Utility functions of pdfTeX for LuaTeX (HO
+)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ifluatex.sty
+Package: ifluatex 2016/05/16 v1.4 Provides the ifluatex switch (HO)
+Package ifluatex Info: LuaTeX not detected.
+)
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ifpdf.sty
+Package: ifpdf 2016/05/14 v3.1 Provides the ifpdf switch
+)
+Package pdftexcmds Info: LuaTeX not detected.
+Package pdftexcmds Info: \pdf@primitive is available.
+Package pdftexcmds Info: \pdf@ifprimitive is available.
+Package pdftexcmds Info: \pdfdraftmode found.
+)
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/epstopdf-base.sty
+Package: epstopdf-base 2016/05/15 v2.6 Base part for package epstopdf
+
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/grfext.sty
+Package: grfext 2016/05/16 v1.2 Manage graphics extensions (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/kvdefinekeys.sty
+Package: kvdefinekeys 2016/05/16 v1.4 Define keys (HO)
+))
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/kvoptions.sty
+Package: kvoptions 2016/05/16 v3.12 Key value format for package options (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/kvsetkeys.sty
+Package: kvsetkeys 2016/05/16 v1.17 Key value parser (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/etexcmds.sty
+Package: etexcmds 2016/05/16 v1.6 Avoid name clashes with e-TeX commands (HO)
+Package etexcmds Info: Could not find \expanded.
+(etexcmds)             That can mean that you are not using pdfTeX 1.50 or
+(etexcmds)             that some package has redefined \expanded.
+(etexcmds)             In the latter case, load this package earlier.
+)))
+Package epstopdf-base Info: Redefining graphics rule for `.eps' on input line 4
+38.
+Package grfext Info: Graphics extension search list:
+(grfext)             [.png,.pdf,.jpg,.mps,.jpeg,.jbig2,.jb2,.PNG,.PDF,.JPG,.JPE
+G,.JBIG2,.JB2,.eps]
+(grfext)             \AppendGraphicsExtensions on input line 456.
+
+(/usr/share/texlive/texmf-dist/tex/latex/latexconfig/epstopdf-sys.cfg
+File: epstopdf-sys.cfg 2010/07/13 v1.3 Configuration of (r)epstopdf for TeX Liv
+e
+))
+Package caption Info: Begin \AtBeginDocument code.
+Package caption Info: End \AtBeginDocument code.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <12> on input line 9.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <8> on input line 9.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <6> on input line 9.
+
+
+LaTeX Warning: No \author given.
+
+
+Underfull \hbox (badness 10000) in paragraph at lines 12--14
+
+ []
+
+<../pics/DSCN2180.JPG, id=1, 803.0pt x 602.25pt>
+File: ../pics/DSCN2180.JPG Graphic file (type jpg)
+ <use ../pics/DSCN2180.JPG>
+Package pdftex.def Info: ../pics/DSCN2180.JPG used on input line 15.
+(pdftex.def)             Requested size: 321.1943pt x 240.89572pt.
+
+
+Package caption Warning: \captionsetup{type*=...} or \captionof
+(caption)                outside box or environment on input line 16.
+See the caption package documentation for explanation.
+
+[1
+
+{/var/lib/texmf/fonts/map/pdftex/updmap/pdftex.map} <../pics/DSCN2180.JPG>]
+LaTeX Font Info:    Try loading font information for OMS+cmr on input line 21.
+
+(/usr/share/texlive/texmf-dist/tex/latex/base/omscmr.fd
+File: omscmr.fd 2014/09/29 v2.5h Standard LaTeX font definitions
+)
+LaTeX Font Info:    Font shape `OMS/cmr/m/n' in size <10.95> not available
+(Font)              Font shape `OMS/cmsy/m/n' tried instead on input line 21.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <10.95> on input line 29.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <9> on input line 29.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <5> on input line 29.
+
+Underfull \hbox (badness 10000) in paragraph at lines 45--46
+[]\OT1/cmr/m/n/10.95 https://thecavepearlproject.org/2019/02/25/no-parts-temper
+ature-
+ []
+
+[2] [3] [4]
+<../pics/esr_impedance_capacitance.png, id=25, 697.10437pt x 421.69917pt>
+File: ../pics/esr_impedance_capacitance.png Graphic file (type png)
+
+<use ../pics/esr_impedance_capacitance.png>
+Package pdftex.def Info: ../pics/esr_impedance_capacitance.png used on input li
+ne 74.
+(pdftex.def)             Requested size: 348.55133pt x 210.84906pt.
+
+Overfull \hbox (13.6647pt too wide) in paragraph at lines 82--82
+[] \OT1/cmtt/m/n/10.95 https://en.wikipedia.org/w/index.php\title=Aluminum_elec
+trolytic 
+ []
+
+[5 <../pics/esr_impedance_capacitance.png (PNG copy)>] [6] (./11.aux) ) 
+Here is how much of TeX's memory you used:
+ 2610 strings out of 494945
+ 41777 string characters out of 6181032
+ 96833 words of memory out of 5000000
+ 5895 multiletter control sequences out of 15000+600000
+ 10544 words of font info for 37 fonts, out of 8000000 for 9000
+ 14 hyphenation exceptions out of 8191
+ 39i,8n,39p,867b,195s stack positions out of 5000i,500n,10000p,200000b,80000s
+</usr/sh
+are/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmbx10.pfb></usr/share/te
+xlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmbx12.pfb></usr/share/texlive/
+texmf-dist/fonts/type1/public/amsfonts/cm/cmr10.pfb></usr/share/texlive/texmf-d
+ist/fonts/type1/public/amsfonts/cm/cmr12.pfb></usr/share/texlive/texmf-dist/fon
+ts/type1/public/amsfonts/cm/cmr6.pfb></usr/share/texlive/texmf-dist/fonts/type1
+/public/amsfonts/cm/cmr8.pfb></usr/share/texlive/texmf-dist/fonts/type1/public/
+amsfonts/cm/cmr9.pfb></usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts
+/cm/cmsy10.pfb></usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cm
+ti10.pfb></usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmtt10.p
+fb>
+Output written on 11.pdf (6 pages, 379400 bytes).
+PDF statistics:
+ 65 PDF objects out of 1000 (max. 8388607)
+ 44 compressed objects within 1 object stream
+ 0 named destinations out of 1000 (max. 500000)
+ 11 words of extra memory for PDF output out of 10000 (max. 10000000)
+

Car_Stereo_Replacement/docs/11.tex

@@ -0,0 +1,96 @@
+\documentclass[11pt]{article}
+%Gummi|065|=)
+\title{\textbf{Car Stereo Replacement}}
+\usepackage{graphicx,caption}
+%\author{Steak Electronics}
+\date{02/13/20}
+\begin{document}
+
+\maketitle
+
+\section{Overview}
+Replacing a car stereo. I could just go to ebay, and buy a used car stereo, but where's the fun in that? Let's DIY a car stereo from a PCB used as a frontplate, a connector for my vehicle, and an audio amplifier. I'll connect in signal from an audio player.
+\\
+
+\includegraphics[scale=0.4]{../pics/DSCN2180.JPG}
+\captionof{figure}{PCB rev 1}
+
+\section{Items Included}
+I thought I would include the following:
+\begin{itemize}
+\item Arduino Nano
+\item Voltage and Gnd Breakout
+\item I2C Display
+\item Voltage Readout (of BAT)
+\item Current Readout (being drawn)
+\end{itemize}
+I also wanted to have the connectors that eurorack and synth designers use for mono audio cables, but the cables turned out too expensive. The current readout didn't work initially, and I haven't gotten to fixing it yet.
+\subsection{I2C OLED display}
+Just for fun, I bought an I2C oled display and am going to use it to display something.\footnote{It's an Arduino Uno, you can put almost anything on this.} Notes on this:
+Using the adafruit SSD1306 and GFX library (this procedure is well covered in other places), you can load an example sketch and get it running. First thing to change is to remove the Adafruit logo and replace it with my own. Let's do that.
+
+From https://design.goeszen.com/convert-image-for-oled-display.html
+\begin{verbatim}
+I'm on Linux here and found that the readily-available 
+ImageMagick package will do the trick for you without
+ any scripting. And runs on the CLI! Simple as that:
+
+    convert some_image.png some.image.mono
+\end{verbatim}
+That's efficient. But it didn't really work out. Too much work, I don't need it that bad. Have to convert it to something the c compiler can read. I instead, just deleted their logo. Good enough for now.
+\subsection{Internal AVR Temperature Sensor}
+
+I setup the code to read from the internal temp sensor on the duino. However there is also this:
+
+https://thecavepearlproject.org/2019/02/25/no-parts-temperature-measurement-with-arduino-pro-mini-to-0-005c-or-better/
+
+This would be something to do for more resolution. The built in sensor is not very good, so this above link would be great. Hack a day also covers it. 
+
+\section{Wiring Pinout is wrong on Internet - Cable has labels}
+I looked at the picture I have detailing the pinout of my car connector (Delco Delphi radio wiring diagram.jpg in resources). It's close, but not 100\% correct. I found that the cable itself has small text labels on each wire which explain which everything does. I didn't notice earlier, as I didn't look close enough (and no one mentioned this).
+
+\section{Arduino VReg Blowout}
+I had a knock off Arduino Nano, and the vreg blew out. I have some other vregs to replace it. I didn't have this problem with an Uno that I use as a ceiling dome light. Although that one is not left on as long, usually. 
+
+\section{Amplifier}
+The amplifier I used is one of the cheapest avialable on ebay. I'm not proud. I'm poor. I had to take it apart, and reseat the amplifier ICs as the tab was not making contact with the chassis for one of them. I also added thermal paste. This amp is underpowered for my car, and may need replacing. It gets a bit hot.
+
+Some other issues with this amplifier are that the output connectors can get pushed back, there is only one output connector option, and it must run on battery power, as a 12V 1A or 2A will not power it. Finally, there is a 6V DC bias on output. No output audio isolation, which means you get car noise.
+
+\section{AC Audio Coupling to Remove DC Noise from Auto}
+I had some fun with this one. Many videos on this in the video folder. I started with the speakers being directly fed by the amplifier. This worked, but there was some noise coming through. Cars are noisy, this is not surprising. I would've preferred the amplifier to isolate the outputs, but no luck... At this point, I considered two options to block DC and allow AC. 1) Use a transformer. 2) Use capacitors.\footnote{A third option would've been to use a second set of batteries, but that would be laborious.}
+
+\subsection{Ground Isolator}
+I had been given a Ground isolator, which was two small transformers on a pcb intended to pass audio from a car powered signal source into the car speakers. I tried this isolator on the output of the speakers, and while it worked, the volume was lower, and it was impractical. I knew as soon as I heard the volume, that the issue was an impedance matching problem. The transformers were too small. They were intended for signal sources, not amplifier outputs. Onto option \#2.
+
+\subsection{Capacitor Audio Coupling}
+My initial thoughts here were: ``Let's be careful and use non polarized caps''. I bought some 0.22uf and 0.022uf polyester film capacitors at Electronics Plus, the local radioshack replacement, and tried them. No sound. After adjusting the connectors on the amp (which were admittedly loose - it's easy to push them back on the amplifier if you are not careful) I found that the capacitors didn't work. One problem was evident in the oscope. I only used one capacitor on the + output of the speaker amp, but the Amp biases the signal 6 volts. So I needed two. After that was resolved, the signal came through on the output of the capacitor, as viewed on the scope, however there was no sound output. I tried the safe way. It's time to break some rules. 
+
+I grabbed some 1uf (electrolytic polarized) caps I had, and tried these. Again, no sound. Not giving up, I grabbed some 1000uf 'lytics, and tried once more. Now it worked.
+
+\subsubsection{Impedance / ESR of capacitors failing to pass enough power of signal}
+Capacitors are rated for impedance. Some data sheets also call this ESR, it appears after a quick look. It's either in there as impedance or ESR. It's not initially an issue if you are using the capacitor as a DC reservoir, but if you use it in an AC coupling situation then things get interesting. A high impedance, or ESR will block what a low one won't. In this example, it's as simple as the Amplfier either being able to power a speaker or not. Higher capacity caps will have lower impedance. See the picture. Other brands put impedance in a graph, or just call it impedance. 
+
+\includegraphics[scale=0.5]{../pics/esr_impedance_capacitance.png}
+\captionof{figure}{Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.}
+
+\subsubsection{Wikipedia on Impedance}
+
+\emph{In general, a capacitor is seen as a storage component for electric energy. But this is only one capacitor function. A capacitor can also act as an AC resistor. Especially aluminum electrolytic capacitors are used in many applications as a decoupling capacitors to filter or bypass undesired biased AC frequencies to the ground or for capacitive coupling of audio AC signals. Then the dielectric is used only for blocking DC. For such applications the AC resistance, the impedance is as important as the capacitance value. }
+\begin{verbatim} https://en.wikipedia.org/w/index.php\title=Aluminum_electrolytic
+_capacitor&oldid=940281525
+\end{verbatim}
+Essentially, what I learned today.
+
+\section{DIY Amp}
+I was flipping through Practical Electronics for Inventors\cite{Scherz}(page 959), when I came across an audio amplifier. He also gives one at the chapter on Semiconductors (pg. 467), although the former is more detailed. With a reasonably simple schematic available, and a high likelihood of it working, I say why not: let's build it up.
+
+\section{References}
+\begin{thebibliography}{99}
+\bibitem{Scherz}
+  Paul Scherz, and Simon Monk,
+  \emph{Practical Electronics for Inventors}, fourth edition - 2016, McGraw Hill.
+
+  \end{thebibliography}
+
+\end{document}

Car_Stereo_Replacement/docs/11.tex~

@@ -0,0 +1,93 @@
+\documentclass[11pt]{article}
+%Gummi|065|=)
+\title{\textbf{Car Stereo Replacement}}
+\usepackage{graphicx,caption}
+%\author{Steak Electronics}
+\date{02/13/20}
+\begin{document}
+
+\maketitle
+
+\section{Overview}
+Replacing a car stereo. I could just go to ebay, and buy a used car stereo, but where's the fun in that? Let's DIY a car stereo from a PCB used as a frontplate, a connector for my vehicle, and an audio amplifier. I'll connect in signal from an audio player.
+
+\includegraphics[scale=0.4]{../pics/DSCN2180.JPG}
+\captionof{figure}{PCB rev 1}
+
+\section{Items Included}
+I thought I would include the following:
+\begin{itemize}
+\item Arduino Nano
+\item Voltage and Gnd Breakout
+\item I2C Display
+\item Voltage Readout (of BAT)
+\item Current Readout (being drawn)
+\end{itemize}
+I also wanted to have the connectors that eurorack and synth designers use for mono audio cables, but the cables turned out too expensive. The current readout didn't work initially, and I haven't gotten to fixing it yet.
+\subsection{I2C OLED display}
+Just for fun, I bought an I2C oled display and am going to use it to display something.\footnote{It's an Arduino Uno, you can put almost anything on this.} Notes on this:
+Using the adafruit SSD1306 and GFX library (this procedure is well covered in other places), you can load an example sketch and get it running. First thing to change is to remove the Adafruit logo and replace it with my own. Let's do that.
+
+From https://design.goeszen.com/convert-image-for-oled-display.html
+\begin{verbatim}
+I'm on Linux here and found that the readily-available 
+ImageMagick package will do the trick for you without
+ any scripting. And runs on the CLI! Simple as that:
+
+    convert some_image.png some.image.mono
+\end{verbatim}
+That's efficient. But it didn't really work out. Too much work, I don't need it that bad. Have to convert it to something the c compiler can read. I instead, just deleted their logo. Good enough for now.
+\subsection{Internal AVR Temperature Sensor}
+
+I setup the code to read from the internal temp sensor on the duino. However there is also this:
+
+https://thecavepearlproject.org/2019/02/25/no-parts-temperature-measurement-with-arduino-pro-mini-to-0-005c-or-better/
+
+This would be something to do for more resolution. The built in sensor is not very good, so this above link would be great. Hack a day also covers it. 
+
+\section{Wiring Pinout is wrong on Internet - Cable has labels}
+I looked at the picture I have detailing the pinout of my car connector (Delco Delphi radio wiring diagram.jpg in resources). It's close, but not 100\% correct. I found that the cable itself has small text labels on each wire which explain which everything does. I didn't notice earlier, as I didn't look close enough (and no one mentioned this).
+
+\section{Arduino VReg Blowout}
+I had a knock off Arduino Nano, and the vreg blew out. I have some other vregs to replace it. I didn't have this problem with an Uno that I use as a ceiling dome light. Although that one is not left on as long, usually. 
+
+\section{Amplifier}
+The amplifier I used is one of the cheapest avialable on ebay. I'm not proud. I'm poor. I had to take it apart, and reseat the amplifier ICs as the tab was not making contact with the chassis for one of them. I also added thermal paste. This amp is underpowered for my car, and may need replacing. It gets a bit hot.
+
+Some other issues with this amplifier are that the output connectors can get pushed back, there is only one output connector option, and it must run on battery power, as a 12V 1A or 2A will not power it. Finally, there is a 6V DC bias on output. No output audio isolation, which means you get car noise.
+
+\section{AC Audio Coupling to Remove DC Noise from Auto}
+I had some fun with this one. Many videos on this in the video folder. I started with the speakers being directly fed by the amplifier. This worked, but there was some noise coming through. Cars are noisy, this is not surprising. I would've preferred the amplifier to isolate the outputs, but no luck... At this point, I considered two options to block DC and allow AC. 1) Use a transformer. 2) Use capacitors.\footnote{A third option would've been to use a second set of batteries, but that would be laborious.}
+
+\subsection{Ground Isolator}
+I had been given a Ground isolator, which was two small transformers on a pcb intended to pass audio from a car powered signal source into the car speakers. I tried this isolator on the output of the speakers, and while it worked, the volume was lower, and it was impractical. I knew as soon as I heard the volume, that the issue was an impedance matching problem. The transformers were too small. They were intended for signal sources, not amplifier outputs. Onto option \#2.
+
+\subsection{Capacitor Audio Coupling}
+My initial thoughts here were: ``Let's be careful and use non polarized caps''. I bought some 0.22uf and 0.022uf polyester film capacitors at Electronics Plus, the local radioshack replacement, and tried them. No sound. After adjusting the connectors on the amp (which were admittedly loose - it's easy to push them back on the amplifier if you are not careful) I found that the capacitors didn't work. One problem was evident in the oscope. I only used one capacitor on the + output of the speaker amp, but the Amp biases the signal 6 volts. So I needed two. After that was resolved, the signal came through on the output of the capacitor, as viewed on the scope, however there was no sound output. I tried the safe way. It's time to break some rules. 
+
+I grabbed some 1uf (electrolytic polarized) caps I had, and tried these. Again, no sound. Not giving up, I grabbed some 1000uf 'lytics, and tried once more. Now it worked.
+
+\subsubsection{Impedance / ESR of capacitors failing to pass enough power of signal}
+Capacitors are rated for impedance. Some data sheets also call this ESR, it appears after a quick look. It's either in there as impedance or ESR. It's not initially an issue if you are using the capacitor as a DC reservoir, but if you use it in an AC coupling situation then things get interesting. A high impedance, or ESR will block what a low one won't. In this example, it's as simple as the Amplfier either being able to power a speaker or not. Higher capacity caps will have lower impedance. See the picture. Other brands put impedance in a graph, or just call it impedance. 
+
+\includegraphics[scale=0.5]{../pics/esr_impedance_capacitance.png}
+\captionof{figure}{Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.}
+
+\subsubsection{Wikipedia on Impedance}
+
+\emph{In general, a capacitor is seen as a storage component for electric energy. But this is only one capacitor function. A capacitor can also act as an AC resistor. Especially aluminum electrolytic capacitors are used in many applications as a decoupling capacitors to filter or bypass undesired biased AC frequencies to the ground or for capacitive coupling of audio AC signals. Then the dielectric is used only for blocking DC. For such applications the AC resistance, the impedance is as important as the capacitance value. }
+\begin{verbatim} https://en.wikipedia.org/w/index.php\title=Aluminum_electrolytic
+_capacitor&oldid=940281525
+\end{verbatim}
+Essentially, what I learned today.
+
+
+\section{References}}
+\begin{thebibliography}{99}
+\bibitem{Scherz}
+  Paul Scherz, and Simon Monk,
+  \emph{Practical Electronics for Inventors}, fourth edition - 2016, McGraw Hill.
+
+  \end{thebibliography}
+
+\end{document}

Car_Stereo_Replacement/docs/12.aux

@@ -0,0 +1,20 @@
+\relax 
+\@writefile{toc}{\contentsline {section}{\numberline {1}Overview}{1}}
+\@writefile{lof}{\contentsline {figure}{\numberline {1}{\ignorespaces PCB rev 1\relax }}{1}}
+\@writefile{toc}{\contentsline {section}{\numberline {2}Items Included}{2}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {2.1}I2C OLED display}{2}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {2.2}Internal AVR Temperature Sensor}{3}}
+\@writefile{toc}{\contentsline {section}{\numberline {3}Wiring Pinout is wrong on Internet - Cable has labels}{3}}
+\@writefile{toc}{\contentsline {section}{\numberline {4}Arduino VReg Blowout}{3}}
+\@writefile{toc}{\contentsline {section}{\numberline {5}Amplifier}{3}}
+\@writefile{toc}{\contentsline {section}{\numberline {6}AC Audio Coupling to Remove DC Noise from Auto}{4}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {6.1}Ground Isolator}{4}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {6.2}Capacitor Audio Coupling}{4}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {6.2.1}Impedance / ESR of capacitors failing to pass enough power of signal}{5}}
+\@writefile{lof}{\contentsline {figure}{\numberline {2}{\ignorespaces Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.\relax }}{5}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {6.2.2}Wikipedia on Impedance}{5}}
+\citation{Scherz}
+\bibcite{Scherz}{1}
+\@writefile{toc}{\contentsline {section}{\numberline {7}DIY Amp}{6}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {7.1}LM383 is Obsolete}{6}}
+\@writefile{toc}{\contentsline {section}{\numberline {8}References}{6}}

Car_Stereo_Replacement/docs/12.log

@@ -0,0 +1,244 @@
+This is pdfTeX, Version 3.14159265-2.6-1.40.17 (TeX Live 2016/Debian) (preloaded format=pdflatex 2019.8.17)  18 FEB 2020 23:59
+entering extended mode
+ restricted \write18 enabled.
+ %&-line parsing enabled.
+**/home/layoutdev/Desktop/code/documentation_general/Electronics_Projects_2019/
+Car_Stereo_Replacement/docs/12.tex
+
+(/home/layoutdev/Desktop/code/documentation_general/Electronics_Projects_2019/C
+ar_Stereo_Replacement/docs/12.tex
+LaTeX2e <2017/01/01> patch level 3
+Babel <3.9r> and hyphenation patterns for 3 language(s) loaded.
+(/usr/share/texlive/texmf-dist/tex/latex/base/article.cls
+Document Class: article 2014/09/29 v1.4h Standard LaTeX document class
+(/usr/share/texlive/texmf-dist/tex/latex/base/size11.clo
+File: size11.clo 2014/09/29 v1.4h Standard LaTeX file (size option)
+)
+\c@part=\count79
+\c@section=\count80
+\c@subsection=\count81
+\c@subsubsection=\count82
+\c@paragraph=\count83
+\c@subparagraph=\count84
+\c@figure=\count85
+\c@table=\count86
+\abovecaptionskip=\skip41
+\belowcaptionskip=\skip42
+\bibindent=\dimen102
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/graphicx.sty
+Package: graphicx 2014/10/28 v1.0g Enhanced LaTeX Graphics (DPC,SPQR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/keyval.sty
+Package: keyval 2014/10/28 v1.15 key=value parser (DPC)
+\KV@toks@=\toks14
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/graphics.sty
+Package: graphics 2016/10/09 v1.0u Standard LaTeX Graphics (DPC,SPQR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/trig.sty
+Package: trig 2016/01/03 v1.10 sin cos tan (DPC)
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics-cfg/graphics.cfg
+File: graphics.cfg 2016/06/04 v1.11 sample graphics configuration
+)
+Package graphics Info: Driver file: pdftex.def on input line 99.
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics-def/pdftex.def
+File: pdftex.def 2017/01/12 v0.06k Graphics/color for pdfTeX
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/infwarerr.sty
+Package: infwarerr 2016/05/16 v1.4 Providing info/warning/error messages (HO)
+)
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ltxcmds.sty
+Package: ltxcmds 2016/05/16 v1.23 LaTeX kernel commands for general use (HO)
+)
+\Gread@gobject=\count87
+))
+\Gin@req@height=\dimen103
+\Gin@req@width=\dimen104
+)
+(/usr/share/texlive/texmf-dist/tex/latex/caption/caption.sty
+Package: caption 2016/02/21 v3.3-144 Customizing captions (AR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/caption/caption3.sty
+Package: caption3 2016/05/22 v1.7-166 caption3 kernel (AR)
+Package caption3 Info: TeX engine: e-TeX on input line 67.
+\captionmargin=\dimen105
+\captionmargin@=\dimen106
+\captionwidth=\dimen107
+\caption@tempdima=\dimen108
+\caption@indent=\dimen109
+\caption@parindent=\dimen110
+\caption@hangindent=\dimen111
+)
+\c@ContinuedFloat=\count88
+) (./12.aux)
+\openout1 = `12.aux'.
+
+LaTeX Font Info:    Checking defaults for OML/cmm/m/it on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for T1/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OT1/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OMS/cmsy/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OMX/cmex/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for U/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+
+(/usr/share/texlive/texmf-dist/tex/context/base/mkii/supp-pdf.mkii
+[Loading MPS to PDF converter (version 2006.09.02).]
+\scratchcounter=\count89
+\scratchdimen=\dimen112
+\scratchbox=\box26
+\nofMPsegments=\count90
+\nofMParguments=\count91
+\everyMPshowfont=\toks15
+\MPscratchCnt=\count92
+\MPscratchDim=\dimen113
+\MPnumerator=\count93
+\makeMPintoPDFobject=\count94
+\everyMPtoPDFconversion=\toks16
+) (/usr/share/texlive/texmf-dist/tex/generic/oberdiek/pdftexcmds.sty
+Package: pdftexcmds 2016/05/21 v0.22 Utility functions of pdfTeX for LuaTeX (HO
+)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ifluatex.sty
+Package: ifluatex 2016/05/16 v1.4 Provides the ifluatex switch (HO)
+Package ifluatex Info: LuaTeX not detected.
+)
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ifpdf.sty
+Package: ifpdf 2016/05/14 v3.1 Provides the ifpdf switch
+)
+Package pdftexcmds Info: LuaTeX not detected.
+Package pdftexcmds Info: \pdf@primitive is available.
+Package pdftexcmds Info: \pdf@ifprimitive is available.
+Package pdftexcmds Info: \pdfdraftmode found.
+)
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/epstopdf-base.sty
+Package: epstopdf-base 2016/05/15 v2.6 Base part for package epstopdf
+
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/grfext.sty
+Package: grfext 2016/05/16 v1.2 Manage graphics extensions (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/kvdefinekeys.sty
+Package: kvdefinekeys 2016/05/16 v1.4 Define keys (HO)
+))
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/kvoptions.sty
+Package: kvoptions 2016/05/16 v3.12 Key value format for package options (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/kvsetkeys.sty
+Package: kvsetkeys 2016/05/16 v1.17 Key value parser (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/etexcmds.sty
+Package: etexcmds 2016/05/16 v1.6 Avoid name clashes with e-TeX commands (HO)
+Package etexcmds Info: Could not find \expanded.
+(etexcmds)             That can mean that you are not using pdfTeX 1.50 or
+(etexcmds)             that some package has redefined \expanded.
+(etexcmds)             In the latter case, load this package earlier.
+)))
+Package epstopdf-base Info: Redefining graphics rule for `.eps' on input line 4
+38.
+Package grfext Info: Graphics extension search list:
+(grfext)             [.png,.pdf,.jpg,.mps,.jpeg,.jbig2,.jb2,.PNG,.PDF,.JPG,.JPE
+G,.JBIG2,.JB2,.eps]
+(grfext)             \AppendGraphicsExtensions on input line 456.
+
+(/usr/share/texlive/texmf-dist/tex/latex/latexconfig/epstopdf-sys.cfg
+File: epstopdf-sys.cfg 2010/07/13 v1.3 Configuration of (r)epstopdf for TeX Liv
+e
+))
+Package caption Info: Begin \AtBeginDocument code.
+Package caption Info: End \AtBeginDocument code.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <12> on input line 9.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <8> on input line 9.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <6> on input line 9.
+
+
+LaTeX Warning: No \author given.
+
+
+Underfull \hbox (badness 10000) in paragraph at lines 12--14
+
+ []
+
+<../pics/DSCN2180.JPG, id=1, 803.0pt x 602.25pt>
+File: ../pics/DSCN2180.JPG Graphic file (type jpg)
+ <use ../pics/DSCN2180.JPG>
+Package pdftex.def Info: ../pics/DSCN2180.JPG used on input line 15.
+(pdftex.def)             Requested size: 321.1943pt x 240.89572pt.
+
+
+Package caption Warning: \captionsetup{type*=...} or \captionof
+(caption)                outside box or environment on input line 16.
+See the caption package documentation for explanation.
+
+[1
+
+{/var/lib/texmf/fonts/map/pdftex/updmap/pdftex.map} <../pics/DSCN2180.JPG>]
+LaTeX Font Info:    Try loading font information for OMS+cmr on input line 21.
+
+(/usr/share/texlive/texmf-dist/tex/latex/base/omscmr.fd
+File: omscmr.fd 2014/09/29 v2.5h Standard LaTeX font definitions
+)
+LaTeX Font Info:    Font shape `OMS/cmr/m/n' in size <10.95> not available
+(Font)              Font shape `OMS/cmsy/m/n' tried instead on input line 21.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <10.95> on input line 30.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <9> on input line 30.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <5> on input line 30.
+
+Underfull \hbox (badness 10000) in paragraph at lines 46--47
+[]\OT1/cmr/m/n/10.95 https://thecavepearlproject.org/2019/02/25/no-parts-temper
+ature-
+ []
+
+[2] [3] [4]
+<../pics/esr_impedance_capacitance.png, id=24, 697.10437pt x 421.69917pt>
+File: ../pics/esr_impedance_capacitance.png Graphic file (type png)
+
+<use ../pics/esr_impedance_capacitance.png>
+Package pdftex.def Info: ../pics/esr_impedance_capacitance.png used on input li
+ne 75.
+(pdftex.def)             Requested size: 348.55133pt x 210.84906pt.
+
+Overfull \hbox (13.6647pt too wide) in paragraph at lines 83--83
+[] \OT1/cmtt/m/n/10.95 https://en.wikipedia.org/w/index.php\title=Aluminum_elec
+trolytic 
+ []
+
+[5 <../pics/esr_impedance_capacitance.png (PNG copy)>] [6] (./12.aux) ) 
+Here is how much of TeX's memory you used:
+ 2610 strings out of 494945
+ 41777 string characters out of 6181032
+ 96833 words of memory out of 5000000
+ 5895 multiletter control sequences out of 15000+600000
+ 10544 words of font info for 37 fonts, out of 8000000 for 9000
+ 14 hyphenation exceptions out of 8191
+ 39i,8n,39p,867b,229s stack positions out of 5000i,500n,10000p,200000b,80000s
+</usr/sh
+are/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmbx10.pfb></usr/share/te
+xlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmbx12.pfb></usr/share/texlive/
+texmf-dist/fonts/type1/public/amsfonts/cm/cmr10.pfb></usr/share/texlive/texmf-d
+ist/fonts/type1/public/amsfonts/cm/cmr12.pfb></usr/share/texlive/texmf-dist/fon
+ts/type1/public/amsfonts/cm/cmr6.pfb></usr/share/texlive/texmf-dist/fonts/type1
+/public/amsfonts/cm/cmr8.pfb></usr/share/texlive/texmf-dist/fonts/type1/public/
+amsfonts/cm/cmr9.pfb></usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts
+/cm/cmsy10.pfb></usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cm
+ti10.pfb></usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmtt10.p
+fb>
+Output written on 12.pdf (6 pages, 385023 bytes).
+PDF statistics:
+ 65 PDF objects out of 1000 (max. 8388607)
+ 44 compressed objects within 1 object stream
+ 0 named destinations out of 1000 (max. 500000)
+ 11 words of extra memory for PDF output out of 10000 (max. 10000000)
+

Car_Stereo_Replacement/docs/12.tex

@@ -0,0 +1,104 @@
+\documentclass[11pt]{article}
+%Gummi|065|=)
+\title{\textbf{Car Stereo Replacement}}
+\usepackage{graphicx,caption}
+%\author{Steak Electronics}
+\date{02/13/20}
+\begin{document}
+
+\maketitle
+
+\section{Overview}
+Replacing a car stereo. I could just go to ebay, and buy a used car stereo, but where's the fun in that? Let's DIY a car stereo from a PCB used as a frontplate, a connector for my vehicle, and an audio amplifier. I'll connect in signal from an audio player.
+\\
+
+\includegraphics[scale=0.4]{../pics/DSCN2180.JPG}
+\captionof{figure}{PCB rev 1}
+
+\section{Items Included}
+I thought I would include the following:
+\begin{itemize}
+\item Arduino Nano
+\item Voltage and Gnd Breakout
+\item I2C Display
+\item Voltage Readout (of BAT)
+\item Current Readout (being drawn)
+\item Amplifier ``Lvpin LP-838''
+\end{itemize}
+I also wanted to have the connectors that eurorack and synth designers use for mono audio cables, but the cables turned out too expensive. The current readout didn't work initially, and I haven't gotten to fixing it yet.
+\subsection{I2C OLED display}
+Just for fun, I bought an I2C oled display and am going to use it to display something.\footnote{It's an Arduino Uno, you can put almost anything on this.} Notes on this:
+Using the adafruit SSD1306 and GFX library (this procedure is well covered in other places), you can load an example sketch and get it running. First thing to change is to remove the Adafruit logo and replace it with my own. Let's do that.
+
+From https://design.goeszen.com/convert-image-for-oled-display.html
+\begin{verbatim}
+I'm on Linux here and found that the readily-available 
+ImageMagick package will do the trick for you without
+ any scripting. And runs on the CLI! Simple as that:
+
+    convert some_image.png some.image.mono
+\end{verbatim}
+That's efficient. But it didn't really work out. Too much work, I don't need it that bad. Have to convert it to something the c compiler can read. I instead, just deleted their logo. Good enough for now.
+\subsection{Internal AVR Temperature Sensor}
+
+I setup the code to read from the internal temp sensor on the duino. However there is also this:
+
+https://thecavepearlproject.org/2019/02/25/no-parts-temperature-measurement-with-arduino-pro-mini-to-0-005c-or-better/
+
+This would be something to do for more resolution. The built in sensor is not very good, so this above link would be great. Hack a day also covers it. 
+
+\section{Wiring Pinout is wrong on Internet - Cable has labels}
+I looked at the picture I have detailing the pinout of my car connector (Delco Delphi radio wiring diagram.jpg in resources). It's close, but not 100\% correct. I found that the cable itself has small text labels on each wire which explain which everything does. I didn't notice earlier, as I didn't look close enough (and no one mentioned this).
+
+\section{Arduino VReg Blowout}
+I had a knock off Arduino Nano, and the vreg blew out. I have some other vregs to replace it. I didn't have this problem with an Uno that I use as a ceiling dome light. Although that one is not left on as long, usually. 
+
+\section{Amplifier}
+The amplifier I used is one of the cheapest avialable on ebay. I'm not proud. I'm poor. I had to take it apart, and reseat the amplifier ICs as the tab was not making contact with the chassis for one of them. I also added thermal paste. This amp is underpowered for my car, and may need replacing. It gets a bit hot.
+
+Some other issues with this amplifier are that the output connectors can get pushed back, there is only one output connector option, and it must run on battery power, as a 12V 1A or 2A will not power it. Finally, there is a 6V DC bias on output. No output audio isolation, which means you get car noise.
+
+\section{AC Audio Coupling to Remove DC Noise from Auto}
+I had some fun with this one. Many videos on this in the video folder. I started with the speakers being directly fed by the amplifier. This worked, but there was some noise coming through. Cars are noisy, this is not surprising. I would've preferred the amplifier to isolate the outputs, but no luck... At this point, I considered two options to block DC and allow AC. 1) Use a transformer. 2) Use capacitors.\footnote{A third option would've been to use a second set of batteries, but that would be laborious.}
+
+\subsection{Ground Isolator}
+I had been given a Ground isolator, which was two small transformers on a pcb intended to pass audio from a car powered signal source into the car speakers. I tried this isolator on the output of the speakers, and while it worked, the volume was lower, and it was impractical. I knew as soon as I heard the volume, that the issue was an impedance matching problem. The transformers were too small. They were intended for signal sources, not amplifier outputs. Onto option \#2.
+
+\subsection{Capacitor Audio Coupling}
+My initial thoughts here were: ``Let's be careful and use non polarized caps''. I bought some 0.22uf and 0.022uf polyester film capacitors at Electronics Plus, the local radioshack replacement, and tried them. No sound. After adjusting the connectors on the amp (which were admittedly loose - it's easy to push them back on the amplifier if you are not careful) I found that the capacitors didn't work. One problem was evident in the oscope. I only used one capacitor on the + output of the speaker amp, but the Amp biases the signal 6 volts. So I needed two. After that was resolved, the signal came through on the output of the capacitor, as viewed on the scope, however there was no sound output. I tried the safe way. It's time to break some rules. 
+
+I grabbed some 1uf (electrolytic polarized) caps I had, and tried these. Again, no sound. Not giving up, I grabbed some 1000uf 'lytics, and tried once more. Now it worked.
+
+\subsubsection{Impedance / ESR of capacitors failing to pass enough power of signal}
+Capacitors are rated for impedance. Some data sheets also call this ESR, it appears after a quick look. It's either in there as impedance or ESR. It's not initially an issue if you are using the capacitor as a DC reservoir, but if you use it in an AC coupling situation then things get interesting. A high impedance, or ESR will block what a low one won't. In this example, it's as simple as the Amplfier either being able to power a speaker or not. Higher capacity caps will have lower impedance. See the picture. Other brands put impedance in a graph, or just call it impedance. 
+
+\includegraphics[scale=0.5]{../pics/esr_impedance_capacitance.png}
+\captionof{figure}{Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.}
+
+\subsubsection{Wikipedia on Impedance}
+
+\emph{In general, a capacitor is seen as a storage component for electric energy. But this is only one capacitor function. A capacitor can also act as an AC resistor. Especially aluminum electrolytic capacitors are used in many applications as a decoupling capacitors to filter or bypass undesired biased AC frequencies to the ground or for capacitive coupling of audio AC signals. Then the dielectric is used only for blocking DC. For such applications the AC resistance, the impedance is as important as the capacitance value. }
+\begin{verbatim} https://en.wikipedia.org/w/index.php\title=Aluminum_electrolytic
+_capacitor&oldid=940281525
+\end{verbatim}
+Essentially, what I learned today.
+
+\section{DIY Amp}
+I was flipping through Practical Electronics for Inventors\cite{Scherz}(page 959), when I came across an audio amplifier. He also gives one at the chapter on Semiconductors (pg. 467), although the former is more detailed. With a reasonably simple schematic available, and a high likelihood of it working, I say why not: let's build it up.
+
+I've noticed that the ``Lvpin LP-838'' amplifier I'm using is underpowered for my two front speakers \footnote{Although it seems it would work for one channel, so two of them might be enough. It's rated for 20W, so that is about 15-20W per channel req'd. It works at 20W for both, just that it heats up too much. Multiple ebay sellers have it misquoted at 200W. Just an extra 0, no biggie. Based on all this, it appears each channel of my car speaker needs about 15 watts to be on the safe side. The example schematic is 16 watts. Two should suffice.}, so I will make two of the provided 16 watt amps.
+
+\subsection{LM383 is Obsolete}
+That explains why I haven't heard of it. The chip is obsolete. Some sell it on ebay for about \$5 each.
+
+As a different route, could I use some other power amplifier op amp, with the same pinout? Hm...
+
+\section{References}
+\begin{thebibliography}{99}
+\bibitem{Scherz}
+  Paul Scherz, and Simon Monk,
+  \emph{Practical Electronics for Inventors}, fourth edition - 2016, McGraw Hill.
+
+  \end{thebibliography}
+
+\end{document}

Car_Stereo_Replacement/docs/12.tex~

@@ -0,0 +1,98 @@
+\documentclass[11pt]{article}
+%Gummi|065|=)
+\title{\textbf{Car Stereo Replacement}}
+\usepackage{graphicx,caption}
+%\author{Steak Electronics}
+\date{02/13/20}
+\begin{document}
+
+\maketitle
+
+\section{Overview}
+Replacing a car stereo. I could just go to ebay, and buy a used car stereo, but where's the fun in that? Let's DIY a car stereo from a PCB used as a frontplate, a connector for my vehicle, and an audio amplifier. I'll connect in signal from an audio player.
+\\
+
+\includegraphics[scale=0.4]{../pics/DSCN2180.JPG}
+\captionof{figure}{PCB rev 1}
+
+\section{Items Included}
+I thought I would include the following:
+\begin{itemize}
+\item Arduino Nano
+\item Voltage and Gnd Breakout
+\item I2C Display
+\item Voltage Readout (of BAT)
+\item Current Readout (being drawn)
+\end{itemize}
+I also wanted to have the connectors that eurorack and synth designers use for mono audio cables, but the cables turned out too expensive. The current readout didn't work initially, and I haven't gotten to fixing it yet.
+\subsection{I2C OLED display}
+Just for fun, I bought an I2C oled display and am going to use it to display something.\footnote{It's an Arduino Uno, you can put almost anything on this.} Notes on this:
+Using the adafruit SSD1306 and GFX library (this procedure is well covered in other places), you can load an example sketch and get it running. First thing to change is to remove the Adafruit logo and replace it with my own. Let's do that.
+
+From https://design.goeszen.com/convert-image-for-oled-display.html
+\begin{verbatim}
+I'm on Linux here and found that the readily-available 
+ImageMagick package will do the trick for you without
+ any scripting. And runs on the CLI! Simple as that:
+
+    convert some_image.png some.image.mono
+\end{verbatim}
+That's efficient. But it didn't really work out. Too much work, I don't need it that bad. Have to convert it to something the c compiler can read. I instead, just deleted their logo. Good enough for now.
+\subsection{Internal AVR Temperature Sensor}
+
+I setup the code to read from the internal temp sensor on the duino. However there is also this:
+
+https://thecavepearlproject.org/2019/02/25/no-parts-temperature-measurement-with-arduino-pro-mini-to-0-005c-or-better/
+
+This would be something to do for more resolution. The built in sensor is not very good, so this above link would be great. Hack a day also covers it. 
+
+\section{Wiring Pinout is wrong on Internet - Cable has labels}
+I looked at the picture I have detailing the pinout of my car connector (Delco Delphi radio wiring diagram.jpg in resources). It's close, but not 100\% correct. I found that the cable itself has small text labels on each wire which explain which everything does. I didn't notice earlier, as I didn't look close enough (and no one mentioned this).
+
+\section{Arduino VReg Blowout}
+I had a knock off Arduino Nano, and the vreg blew out. I have some other vregs to replace it. I didn't have this problem with an Uno that I use as a ceiling dome light. Although that one is not left on as long, usually. 
+
+\section{Amplifier}
+The amplifier I used is one of the cheapest avialable on ebay. I'm not proud. I'm poor. I had to take it apart, and reseat the amplifier ICs as the tab was not making contact with the chassis for one of them. I also added thermal paste. This amp is underpowered for my car, and may need replacing. It gets a bit hot.
+
+Some other issues with this amplifier are that the output connectors can get pushed back, there is only one output connector option, and it must run on battery power, as a 12V 1A or 2A will not power it. Finally, there is a 6V DC bias on output. No output audio isolation, which means you get car noise.
+
+\section{AC Audio Coupling to Remove DC Noise from Auto}
+I had some fun with this one. Many videos on this in the video folder. I started with the speakers being directly fed by the amplifier. This worked, but there was some noise coming through. Cars are noisy, this is not surprising. I would've preferred the amplifier to isolate the outputs, but no luck... At this point, I considered two options to block DC and allow AC. 1) Use a transformer. 2) Use capacitors.\footnote{A third option would've been to use a second set of batteries, but that would be laborious.}
+
+\subsection{Ground Isolator}
+I had been given a Ground isolator, which was two small transformers on a pcb intended to pass audio from a car powered signal source into the car speakers. I tried this isolator on the output of the speakers, and while it worked, the volume was lower, and it was impractical. I knew as soon as I heard the volume, that the issue was an impedance matching problem. The transformers were too small. They were intended for signal sources, not amplifier outputs. Onto option \#2.
+
+\subsection{Capacitor Audio Coupling}
+My initial thoughts here were: ``Let's be careful and use non polarized caps''. I bought some 0.22uf and 0.022uf polyester film capacitors at Electronics Plus, the local radioshack replacement, and tried them. No sound. After adjusting the connectors on the amp (which were admittedly loose - it's easy to push them back on the amplifier if you are not careful) I found that the capacitors didn't work. One problem was evident in the oscope. I only used one capacitor on the + output of the speaker amp, but the Amp biases the signal 6 volts. So I needed two. After that was resolved, the signal came through on the output of the capacitor, as viewed on the scope, however there was no sound output. I tried the safe way. It's time to break some rules. 
+
+I grabbed some 1uf (electrolytic polarized) caps I had, and tried these. Again, no sound. Not giving up, I grabbed some 1000uf 'lytics, and tried once more. Now it worked.
+
+\subsubsection{Impedance / ESR of capacitors failing to pass enough power of signal}
+Capacitors are rated for impedance. Some data sheets also call this ESR, it appears after a quick look. It's either in there as impedance or ESR. It's not initially an issue if you are using the capacitor as a DC reservoir, but if you use it in an AC coupling situation then things get interesting. A high impedance, or ESR will block what a low one won't. In this example, it's as simple as the Amplfier either being able to power a speaker or not. Higher capacity caps will have lower impedance. See the picture. Other brands put impedance in a graph, or just call it impedance. 
+
+\includegraphics[scale=0.5]{../pics/esr_impedance_capacitance.png}
+\captionof{figure}{Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.}
+
+\subsubsection{Wikipedia on Impedance}
+
+\emph{In general, a capacitor is seen as a storage component for electric energy. But this is only one capacitor function. A capacitor can also act as an AC resistor. Especially aluminum electrolytic capacitors are used in many applications as a decoupling capacitors to filter or bypass undesired biased AC frequencies to the ground or for capacitive coupling of audio AC signals. Then the dielectric is used only for blocking DC. For such applications the AC resistance, the impedance is as important as the capacitance value. }
+\begin{verbatim} https://en.wikipedia.org/w/index.php\title=Aluminum_electrolytic
+_capacitor&oldid=940281525
+\end{verbatim}
+Essentially, what I learned today.
+
+\section{DIY Amp}
+I was flipping through Practical Electronics for Inventors\cite{Scherz}(page 959), when I came across an audio amplifier. He also gives one at the chapter on Semiconductors (pg. 467), although the former is more detailed. With a reasonably simple schematic available, and a high likelihood of it working, I say why not: let's build it up.
+
+I've noticed that the ``Lvpin LP-838'' amplifier I'm using is underpowered for my two front speakers \footnote{Although it seems it would work for one channel, so two of them might be enough. It's rated for 20W, so that is about 20W per channel. It works at 20W for both, just that it heats up too much. Multiple ebay sellers have it misquoted at 200W. Just an extra 0, no biggie. Based on all this, it appears each channel of my car speaker needs about 15 watts to be on the safe side. The example schematic is 16 watts. Two should suffice.}
+
+\section{References}
+\begin{thebibliography}{99}
+\bibitem{Scherz}
+  Paul Scherz, and Simon Monk,
+  \emph{Practical Electronics for Inventors}, fourth edition - 2016, McGraw Hill.
+
+  \end{thebibliography}
+
+\end{document}

Car_Stereo_Replacement/docs/12tex

@@ -0,0 +1,98 @@
+\documentclass[11pt]{article}
+%Gummi|065|=)
+\title{\textbf{Car Stereo Replacement}}
+\usepackage{graphicx,caption}
+%\author{Steak Electronics}
+\date{02/13/20}
+\begin{document}
+
+\maketitle
+
+\section{Overview}
+Replacing a car stereo. I could just go to ebay, and buy a used car stereo, but where's the fun in that? Let's DIY a car stereo from a PCB used as a frontplate, a connector for my vehicle, and an audio amplifier. I'll connect in signal from an audio player.
+\\
+
+\includegraphics[scale=0.4]{../pics/DSCN2180.JPG}
+\captionof{figure}{PCB rev 1}
+
+\section{Items Included}
+I thought I would include the following:
+\begin{itemize}
+\item Arduino Nano
+\item Voltage and Gnd Breakout
+\item I2C Display
+\item Voltage Readout (of BAT)
+\item Current Readout (being drawn)
+\end{itemize}
+I also wanted to have the connectors that eurorack and synth designers use for mono audio cables, but the cables turned out too expensive. The current readout didn't work initially, and I haven't gotten to fixing it yet.
+\subsection{I2C OLED display}
+Just for fun, I bought an I2C oled display and am going to use it to display something.\footnote{It's an Arduino Uno, you can put almost anything on this.} Notes on this:
+Using the adafruit SSD1306 and GFX library (this procedure is well covered in other places), you can load an example sketch and get it running. First thing to change is to remove the Adafruit logo and replace it with my own. Let's do that.
+
+From https://design.goeszen.com/convert-image-for-oled-display.html
+\begin{verbatim}
+I'm on Linux here and found that the readily-available 
+ImageMagick package will do the trick for you without
+ any scripting. And runs on the CLI! Simple as that:
+
+    convert some_image.png some.image.mono
+\end{verbatim}
+That's efficient. But it didn't really work out. Too much work, I don't need it that bad. Have to convert it to something the c compiler can read. I instead, just deleted their logo. Good enough for now.
+\subsection{Internal AVR Temperature Sensor}
+
+I setup the code to read from the internal temp sensor on the duino. However there is also this:
+
+https://thecavepearlproject.org/2019/02/25/no-parts-temperature-measurement-with-arduino-pro-mini-to-0-005c-or-better/
+
+This would be something to do for more resolution. The built in sensor is not very good, so this above link would be great. Hack a day also covers it. 
+
+\section{Wiring Pinout is wrong on Internet - Cable has labels}
+I looked at the picture I have detailing the pinout of my car connector (Delco Delphi radio wiring diagram.jpg in resources). It's close, but not 100\% correct. I found that the cable itself has small text labels on each wire which explain which everything does. I didn't notice earlier, as I didn't look close enough (and no one mentioned this).
+
+\section{Arduino VReg Blowout}
+I had a knock off Arduino Nano, and the vreg blew out. I have some other vregs to replace it. I didn't have this problem with an Uno that I use as a ceiling dome light. Although that one is not left on as long, usually. 
+
+\section{Amplifier}
+The amplifier I used is one of the cheapest avialable on ebay. I'm not proud. I'm poor. I had to take it apart, and reseat the amplifier ICs as the tab was not making contact with the chassis for one of them. I also added thermal paste. This amp is underpowered for my car, and may need replacing. It gets a bit hot.
+
+Some other issues with this amplifier are that the output connectors can get pushed back, there is only one output connector option, and it must run on battery power, as a 12V 1A or 2A will not power it. Finally, there is a 6V DC bias on output. No output audio isolation, which means you get car noise.
+
+\section{AC Audio Coupling to Remove DC Noise from Auto}
+I had some fun with this one. Many videos on this in the video folder. I started with the speakers being directly fed by the amplifier. This worked, but there was some noise coming through. Cars are noisy, this is not surprising. I would've preferred the amplifier to isolate the outputs, but no luck... At this point, I considered two options to block DC and allow AC. 1) Use a transformer. 2) Use capacitors.\footnote{A third option would've been to use a second set of batteries, but that would be laborious.}
+
+\subsection{Ground Isolator}
+I had been given a Ground isolator, which was two small transformers on a pcb intended to pass audio from a car powered signal source into the car speakers. I tried this isolator on the output of the speakers, and while it worked, the volume was lower, and it was impractical. I knew as soon as I heard the volume, that the issue was an impedance matching problem. The transformers were too small. They were intended for signal sources, not amplifier outputs. Onto option \#2.
+
+\subsection{Capacitor Audio Coupling}
+My initial thoughts here were: ``Let's be careful and use non polarized caps''. I bought some 0.22uf and 0.022uf polyester film capacitors at Electronics Plus, the local radioshack replacement, and tried them. No sound. After adjusting the connectors on the amp (which were admittedly loose - it's easy to push them back on the amplifier if you are not careful) I found that the capacitors didn't work. One problem was evident in the oscope. I only used one capacitor on the + output of the speaker amp, but the Amp biases the signal 6 volts. So I needed two. After that was resolved, the signal came through on the output of the capacitor, as viewed on the scope, however there was no sound output. I tried the safe way. It's time to break some rules. 
+
+I grabbed some 1uf (electrolytic polarized) caps I had, and tried these. Again, no sound. Not giving up, I grabbed some 1000uf 'lytics, and tried once more. Now it worked.
+
+\subsubsection{Impedance / ESR of capacitors failing to pass enough power of signal}
+Capacitors are rated for impedance. Some data sheets also call this ESR, it appears after a quick look. It's either in there as impedance or ESR. It's not initially an issue if you are using the capacitor as a DC reservoir, but if you use it in an AC coupling situation then things get interesting. A high impedance, or ESR will block what a low one won't. In this example, it's as simple as the Amplfier either being able to power a speaker or not. Higher capacity caps will have lower impedance. See the picture. Other brands put impedance in a graph, or just call it impedance. 
+
+\includegraphics[scale=0.5]{../pics/esr_impedance_capacitance.png}
+\captionof{figure}{Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.}
+
+\subsubsection{Wikipedia on Impedance}
+
+\emph{In general, a capacitor is seen as a storage component for electric energy. But this is only one capacitor function. A capacitor can also act as an AC resistor. Especially aluminum electrolytic capacitors are used in many applications as a decoupling capacitors to filter or bypass undesired biased AC frequencies to the ground or for capacitive coupling of audio AC signals. Then the dielectric is used only for blocking DC. For such applications the AC resistance, the impedance is as important as the capacitance value. }
+\begin{verbatim} https://en.wikipedia.org/w/index.php\title=Aluminum_electrolytic
+_capacitor&oldid=940281525
+\end{verbatim}
+Essentially, what I learned today.
+
+\section{DIY Amp}
+I was flipping through Practical Electronics for Inventors\cite{Scherz}(page 959), when I came across an audio amplifier. He also gives one at the chapter on Semiconductors (pg. 467), although the former is more detailed. With a reasonably simple schematic available, and a high likelihood of it working, I say why not: let's build it up.
+
+I've noticed that the ``Lvpin LP-838'' amplifier I'm using is underpowered for my two front speakers \footnote{Although it seems it would work for one channel, so two of them might be enough. It's rated for 20W, so that is about 20W per channel. It works at 20W for both, just that it heats up too much. Multiple ebay sellers have it misquoted at 200W. Just an extra 0, no biggie. Based on all this, it appears each channel of my car speaker needs about 15 watts to be on the safe side. The example schematic is 16 watts. Two should suffice.}
+
+\section{References}
+\begin{thebibliography}{99}
+\bibitem{Scherz}
+  Paul Scherz, and Simon Monk,
+  \emph{Practical Electronics for Inventors}, fourth edition - 2016, McGraw Hill.
+
+  \end{thebibliography}
+
+\end{document}

Car_Stereo_Replacement/docs/12tex.aux

@@ -0,0 +1,19 @@
+\relax 
+\@writefile{toc}{\contentsline {section}{\numberline {1}Overview}{1}}
+\@writefile{lof}{\contentsline {figure}{\numberline {1}{\ignorespaces PCB rev 1\relax }}{1}}
+\@writefile{toc}{\contentsline {section}{\numberline {2}Items Included}{2}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {2.1}I2C OLED display}{2}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {2.2}Internal AVR Temperature Sensor}{2}}
+\@writefile{toc}{\contentsline {section}{\numberline {3}Wiring Pinout is wrong on Internet - Cable has labels}{3}}
+\@writefile{toc}{\contentsline {section}{\numberline {4}Arduino VReg Blowout}{3}}
+\@writefile{toc}{\contentsline {section}{\numberline {5}Amplifier}{3}}
+\@writefile{toc}{\contentsline {section}{\numberline {6}AC Audio Coupling to Remove DC Noise from Auto}{3}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {6.1}Ground Isolator}{4}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {6.2}Capacitor Audio Coupling}{4}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {6.2.1}Impedance / ESR of capacitors failing to pass enough power of signal}{4}}
+\citation{Scherz}
+\@writefile{lof}{\contentsline {figure}{\numberline {2}{\ignorespaces Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.\relax }}{5}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {6.2.2}Wikipedia on Impedance}{5}}
+\bibcite{Scherz}{1}
+\@writefile{toc}{\contentsline {section}{\numberline {7}DIY Amp}{6}}
+\@writefile{toc}{\contentsline {section}{\numberline {8}References}{6}}

Car_Stereo_Replacement/docs/12tex.log

@@ -0,0 +1,244 @@
+This is pdfTeX, Version 3.14159265-2.6-1.40.17 (TeX Live 2016/Debian) (preloaded format=pdflatex 2019.8.17)  18 FEB 2020 23:12
+entering extended mode
+ restricted \write18 enabled.
+ %&-line parsing enabled.
+**/home/layoutdev/Desktop/code/documentation_general/Electronics_Projects_2019/
+Car_Stereo_Replacement/docs/12tex
+
+(/home/layoutdev/Desktop/code/documentation_general/Electronics_Projects_2019/C
+ar_Stereo_Replacement/docs/12tex
+LaTeX2e <2017/01/01> patch level 3
+Babel <3.9r> and hyphenation patterns for 3 language(s) loaded.
+(/usr/share/texlive/texmf-dist/tex/latex/base/article.cls
+Document Class: article 2014/09/29 v1.4h Standard LaTeX document class
+(/usr/share/texlive/texmf-dist/tex/latex/base/size11.clo
+File: size11.clo 2014/09/29 v1.4h Standard LaTeX file (size option)
+)
+\c@part=\count79
+\c@section=\count80
+\c@subsection=\count81
+\c@subsubsection=\count82
+\c@paragraph=\count83
+\c@subparagraph=\count84
+\c@figure=\count85
+\c@table=\count86
+\abovecaptionskip=\skip41
+\belowcaptionskip=\skip42
+\bibindent=\dimen102
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/graphicx.sty
+Package: graphicx 2014/10/28 v1.0g Enhanced LaTeX Graphics (DPC,SPQR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/keyval.sty
+Package: keyval 2014/10/28 v1.15 key=value parser (DPC)
+\KV@toks@=\toks14
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/graphics.sty
+Package: graphics 2016/10/09 v1.0u Standard LaTeX Graphics (DPC,SPQR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/trig.sty
+Package: trig 2016/01/03 v1.10 sin cos tan (DPC)
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics-cfg/graphics.cfg
+File: graphics.cfg 2016/06/04 v1.11 sample graphics configuration
+)
+Package graphics Info: Driver file: pdftex.def on input line 99.
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics-def/pdftex.def
+File: pdftex.def 2017/01/12 v0.06k Graphics/color for pdfTeX
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/infwarerr.sty
+Package: infwarerr 2016/05/16 v1.4 Providing info/warning/error messages (HO)
+)
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ltxcmds.sty
+Package: ltxcmds 2016/05/16 v1.23 LaTeX kernel commands for general use (HO)
+)
+\Gread@gobject=\count87
+))
+\Gin@req@height=\dimen103
+\Gin@req@width=\dimen104
+)
+(/usr/share/texlive/texmf-dist/tex/latex/caption/caption.sty
+Package: caption 2016/02/21 v3.3-144 Customizing captions (AR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/caption/caption3.sty
+Package: caption3 2016/05/22 v1.7-166 caption3 kernel (AR)
+Package caption3 Info: TeX engine: e-TeX on input line 67.
+\captionmargin=\dimen105
+\captionmargin@=\dimen106
+\captionwidth=\dimen107
+\caption@tempdima=\dimen108
+\caption@indent=\dimen109
+\caption@parindent=\dimen110
+\caption@hangindent=\dimen111
+)
+\c@ContinuedFloat=\count88
+) (./12tex.aux)
+\openout1 = `12tex.aux'.
+
+LaTeX Font Info:    Checking defaults for OML/cmm/m/it on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for T1/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OT1/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OMS/cmsy/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OMX/cmex/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for U/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+
+(/usr/share/texlive/texmf-dist/tex/context/base/mkii/supp-pdf.mkii
+[Loading MPS to PDF converter (version 2006.09.02).]
+\scratchcounter=\count89
+\scratchdimen=\dimen112
+\scratchbox=\box26
+\nofMPsegments=\count90
+\nofMParguments=\count91
+\everyMPshowfont=\toks15
+\MPscratchCnt=\count92
+\MPscratchDim=\dimen113
+\MPnumerator=\count93
+\makeMPintoPDFobject=\count94
+\everyMPtoPDFconversion=\toks16
+) (/usr/share/texlive/texmf-dist/tex/generic/oberdiek/pdftexcmds.sty
+Package: pdftexcmds 2016/05/21 v0.22 Utility functions of pdfTeX for LuaTeX (HO
+)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ifluatex.sty
+Package: ifluatex 2016/05/16 v1.4 Provides the ifluatex switch (HO)
+Package ifluatex Info: LuaTeX not detected.
+)
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ifpdf.sty
+Package: ifpdf 2016/05/14 v3.1 Provides the ifpdf switch
+)
+Package pdftexcmds Info: LuaTeX not detected.
+Package pdftexcmds Info: \pdf@primitive is available.
+Package pdftexcmds Info: \pdf@ifprimitive is available.
+Package pdftexcmds Info: \pdfdraftmode found.
+)
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/epstopdf-base.sty
+Package: epstopdf-base 2016/05/15 v2.6 Base part for package epstopdf
+
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/grfext.sty
+Package: grfext 2016/05/16 v1.2 Manage graphics extensions (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/kvdefinekeys.sty
+Package: kvdefinekeys 2016/05/16 v1.4 Define keys (HO)
+))
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/kvoptions.sty
+Package: kvoptions 2016/05/16 v3.12 Key value format for package options (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/kvsetkeys.sty
+Package: kvsetkeys 2016/05/16 v1.17 Key value parser (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/etexcmds.sty
+Package: etexcmds 2016/05/16 v1.6 Avoid name clashes with e-TeX commands (HO)
+Package etexcmds Info: Could not find \expanded.
+(etexcmds)             That can mean that you are not using pdfTeX 1.50 or
+(etexcmds)             that some package has redefined \expanded.
+(etexcmds)             In the latter case, load this package earlier.
+)))
+Package epstopdf-base Info: Redefining graphics rule for `.eps' on input line 4
+38.
+Package grfext Info: Graphics extension search list:
+(grfext)             [.png,.pdf,.jpg,.mps,.jpeg,.jbig2,.jb2,.PNG,.PDF,.JPG,.JPE
+G,.JBIG2,.JB2,.eps]
+(grfext)             \AppendGraphicsExtensions on input line 456.
+
+(/usr/share/texlive/texmf-dist/tex/latex/latexconfig/epstopdf-sys.cfg
+File: epstopdf-sys.cfg 2010/07/13 v1.3 Configuration of (r)epstopdf for TeX Liv
+e
+))
+Package caption Info: Begin \AtBeginDocument code.
+Package caption Info: End \AtBeginDocument code.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <12> on input line 9.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <8> on input line 9.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <6> on input line 9.
+
+
+LaTeX Warning: No \author given.
+
+
+Underfull \hbox (badness 10000) in paragraph at lines 12--14
+
+ []
+
+<../pics/DSCN2180.JPG, id=1, 803.0pt x 602.25pt>
+File: ../pics/DSCN2180.JPG Graphic file (type jpg)
+ <use ../pics/DSCN2180.JPG>
+Package pdftex.def Info: ../pics/DSCN2180.JPG used on input line 15.
+(pdftex.def)             Requested size: 321.1943pt x 240.89572pt.
+
+
+Package caption Warning: \captionsetup{type*=...} or \captionof
+(caption)                outside box or environment on input line 16.
+See the caption package documentation for explanation.
+
+[1
+
+{/var/lib/texmf/fonts/map/pdftex/updmap/pdftex.map} <../pics/DSCN2180.JPG>]
+LaTeX Font Info:    Try loading font information for OMS+cmr on input line 21.
+
+(/usr/share/texlive/texmf-dist/tex/latex/base/omscmr.fd
+File: omscmr.fd 2014/09/29 v2.5h Standard LaTeX font definitions
+)
+LaTeX Font Info:    Font shape `OMS/cmr/m/n' in size <10.95> not available
+(Font)              Font shape `OMS/cmsy/m/n' tried instead on input line 21.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <10.95> on input line 29.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <9> on input line 29.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <5> on input line 29.
+
+Underfull \hbox (badness 10000) in paragraph at lines 45--46
+[]\OT1/cmr/m/n/10.95 https://thecavepearlproject.org/2019/02/25/no-parts-temper
+ature-
+ []
+
+[2] [3] [4]
+<../pics/esr_impedance_capacitance.png, id=25, 697.10437pt x 421.69917pt>
+File: ../pics/esr_impedance_capacitance.png Graphic file (type png)
+
+<use ../pics/esr_impedance_capacitance.png>
+Package pdftex.def Info: ../pics/esr_impedance_capacitance.png used on input li
+ne 74.
+(pdftex.def)             Requested size: 348.55133pt x 210.84906pt.
+
+Overfull \hbox (13.6647pt too wide) in paragraph at lines 82--82
+[] \OT1/cmtt/m/n/10.95 https://en.wikipedia.org/w/index.php\title=Aluminum_elec
+trolytic 
+ []
+
+[5 <../pics/esr_impedance_capacitance.png (PNG copy)>] [6] (./12tex.aux) ) 
+Here is how much of TeX's memory you used:
+ 2610 strings out of 494945
+ 41796 string characters out of 6181032
+ 96833 words of memory out of 5000000
+ 5895 multiletter control sequences out of 15000+600000
+ 10544 words of font info for 37 fonts, out of 8000000 for 9000
+ 14 hyphenation exceptions out of 8191
+ 39i,8n,39p,866b,195s stack positions out of 5000i,500n,10000p,200000b,80000s
+</usr
+/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmbx10.pfb></usr/share
+/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmbx12.pfb></usr/share/texli
+ve/texmf-dist/fonts/type1/public/amsfonts/cm/cmr10.pfb></usr/share/texlive/texm
+f-dist/fonts/type1/public/amsfonts/cm/cmr12.pfb></usr/share/texlive/texmf-dist/
+fonts/type1/public/amsfonts/cm/cmr6.pfb></usr/share/texlive/texmf-dist/fonts/ty
+pe1/public/amsfonts/cm/cmr8.pfb></usr/share/texlive/texmf-dist/fonts/type1/publ
+ic/amsfonts/cm/cmr9.pfb></usr/share/texlive/texmf-dist/fonts/type1/public/amsfo
+nts/cm/cmsy10.pfb></usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm
+/cmti10.pfb></usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmtt1
+0.pfb>
+Output written on 12tex.pdf (6 pages, 384078 bytes).
+PDF statistics:
+ 65 PDF objects out of 1000 (max. 8388607)
+ 44 compressed objects within 1 object stream
+ 0 named destinations out of 1000 (max. 500000)
+ 11 words of extra memory for PDF output out of 10000 (max. 10000000)
+

Car_Stereo_Replacement/docs/12tex~

@@ -0,0 +1,98 @@
+\documentclass[11pt]{article}
+%Gummi|065|=)
+\title{\textbf{Car Stereo Replacement}}
+\usepackage{graphicx,caption}
+%\author{Steak Electronics}
+\date{02/13/20}
+\begin{document}
+
+\maketitle
+
+\section{Overview}
+Replacing a car stereo. I could just go to ebay, and buy a used car stereo, but where's the fun in that? Let's DIY a car stereo from a PCB used as a frontplate, a connector for my vehicle, and an audio amplifier. I'll connect in signal from an audio player.
+\\
+
+\includegraphics[scale=0.4]{../pics/DSCN2180.JPG}
+\captionof{figure}{PCB rev 1}
+
+\section{Items Included}
+I thought I would include the following:
+\begin{itemize}
+\item Arduino Nano
+\item Voltage and Gnd Breakout
+\item I2C Display
+\item Voltage Readout (of BAT)
+\item Current Readout (being drawn)
+\end{itemize}
+I also wanted to have the connectors that eurorack and synth designers use for mono audio cables, but the cables turned out too expensive. The current readout didn't work initially, and I haven't gotten to fixing it yet.
+\subsection{I2C OLED display}
+Just for fun, I bought an I2C oled display and am going to use it to display something.\footnote{It's an Arduino Uno, you can put almost anything on this.} Notes on this:
+Using the adafruit SSD1306 and GFX library (this procedure is well covered in other places), you can load an example sketch and get it running. First thing to change is to remove the Adafruit logo and replace it with my own. Let's do that.
+
+From https://design.goeszen.com/convert-image-for-oled-display.html
+\begin{verbatim}
+I'm on Linux here and found that the readily-available 
+ImageMagick package will do the trick for you without
+ any scripting. And runs on the CLI! Simple as that:
+
+    convert some_image.png some.image.mono
+\end{verbatim}
+That's efficient. But it didn't really work out. Too much work, I don't need it that bad. Have to convert it to something the c compiler can read. I instead, just deleted their logo. Good enough for now.
+\subsection{Internal AVR Temperature Sensor}
+
+I setup the code to read from the internal temp sensor on the duino. However there is also this:
+
+https://thecavepearlproject.org/2019/02/25/no-parts-temperature-measurement-with-arduino-pro-mini-to-0-005c-or-better/
+
+This would be something to do for more resolution. The built in sensor is not very good, so this above link would be great. Hack a day also covers it. 
+
+\section{Wiring Pinout is wrong on Internet - Cable has labels}
+I looked at the picture I have detailing the pinout of my car connector (Delco Delphi radio wiring diagram.jpg in resources). It's close, but not 100\% correct. I found that the cable itself has small text labels on each wire which explain which everything does. I didn't notice earlier, as I didn't look close enough (and no one mentioned this).
+
+\section{Arduino VReg Blowout}
+I had a knock off Arduino Nano, and the vreg blew out. I have some other vregs to replace it. I didn't have this problem with an Uno that I use as a ceiling dome light. Although that one is not left on as long, usually. 
+
+\section{Amplifier}
+The amplifier I used is one of the cheapest avialable on ebay. I'm not proud. I'm poor. I had to take it apart, and reseat the amplifier ICs as the tab was not making contact with the chassis for one of them. I also added thermal paste. This amp is underpowered for my car, and may need replacing. It gets a bit hot.
+
+Some other issues with this amplifier are that the output connectors can get pushed back, there is only one output connector option, and it must run on battery power, as a 12V 1A or 2A will not power it. Finally, there is a 6V DC bias on output. No output audio isolation, which means you get car noise.
+
+\section{AC Audio Coupling to Remove DC Noise from Auto}
+I had some fun with this one. Many videos on this in the video folder. I started with the speakers being directly fed by the amplifier. This worked, but there was some noise coming through. Cars are noisy, this is not surprising. I would've preferred the amplifier to isolate the outputs, but no luck... At this point, I considered two options to block DC and allow AC. 1) Use a transformer. 2) Use capacitors.\footnote{A third option would've been to use a second set of batteries, but that would be laborious.}
+
+\subsection{Ground Isolator}
+I had been given a Ground isolator, which was two small transformers on a pcb intended to pass audio from a car powered signal source into the car speakers. I tried this isolator on the output of the speakers, and while it worked, the volume was lower, and it was impractical. I knew as soon as I heard the volume, that the issue was an impedance matching problem. The transformers were too small. They were intended for signal sources, not amplifier outputs. Onto option \#2.
+
+\subsection{Capacitor Audio Coupling}
+My initial thoughts here were: ``Let's be careful and use non polarized caps''. I bought some 0.22uf and 0.022uf polyester film capacitors at Electronics Plus, the local radioshack replacement, and tried them. No sound. After adjusting the connectors on the amp (which were admittedly loose - it's easy to push them back on the amplifier if you are not careful) I found that the capacitors didn't work. One problem was evident in the oscope. I only used one capacitor on the + output of the speaker amp, but the Amp biases the signal 6 volts. So I needed two. After that was resolved, the signal came through on the output of the capacitor, as viewed on the scope, however there was no sound output. I tried the safe way. It's time to break some rules. 
+
+I grabbed some 1uf (electrolytic polarized) caps I had, and tried these. Again, no sound. Not giving up, I grabbed some 1000uf 'lytics, and tried once more. Now it worked.
+
+\subsubsection{Impedance / ESR of capacitors failing to pass enough power of signal}
+Capacitors are rated for impedance. Some data sheets also call this ESR, it appears after a quick look. It's either in there as impedance or ESR. It's not initially an issue if you are using the capacitor as a DC reservoir, but if you use it in an AC coupling situation then things get interesting. A high impedance, or ESR will block what a low one won't. In this example, it's as simple as the Amplfier either being able to power a speaker or not. Higher capacity caps will have lower impedance. See the picture. Other brands put impedance in a graph, or just call it impedance. 
+
+\includegraphics[scale=0.5]{../pics/esr_impedance_capacitance.png}
+\captionof{figure}{Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.}
+
+\subsubsection{Wikipedia on Impedance}
+
+\emph{In general, a capacitor is seen as a storage component for electric energy. But this is only one capacitor function. A capacitor can also act as an AC resistor. Especially aluminum electrolytic capacitors are used in many applications as a decoupling capacitors to filter or bypass undesired biased AC frequencies to the ground or for capacitive coupling of audio AC signals. Then the dielectric is used only for blocking DC. For such applications the AC resistance, the impedance is as important as the capacitance value. }
+\begin{verbatim} https://en.wikipedia.org/w/index.php\title=Aluminum_electrolytic
+_capacitor&oldid=940281525
+\end{verbatim}
+Essentially, what I learned today.
+
+\section{DIY Amp}
+I was flipping through Practical Electronics for Inventors\cite{Scherz}(page 959), when I came across an audio amplifier. He also gives one at the chapter on Semiconductors (pg. 467), although the former is more detailed. With a reasonably simple schematic available, and a high likelihood of it working, I say why not: let's build it up.
+
+I've noticed that the Lvpin LP-838 amplifier I'm using is underpowered for my two front speakers \footnote{Although it seems it would work for one channel, so two of them might be enough. It's rated for 20W, so that is about 20W per channel. It works at 20W for both, just that it heats up too much.}
+
+\section{References}
+\begin{thebibliography}{99}
+\bibitem{Scherz}
+  Paul Scherz, and Simon Monk,
+  \emph{Practical Electronics for Inventors}, fourth edition - 2016, McGraw Hill.
+
+  \end{thebibliography}
+
+\end{document}

Car_Stereo_Replacement/docs/13.aux

@@ -0,0 +1,20 @@
+\relax 
+\@writefile{toc}{\contentsline {section}{\numberline {1}Overview}{1}}
+\@writefile{lof}{\contentsline {figure}{\numberline {1}{\ignorespaces PCB rev 1\relax }}{1}}
+\@writefile{toc}{\contentsline {section}{\numberline {2}Items Included}{2}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {2.1}I2C OLED display}{2}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {2.2}Internal AVR Temperature Sensor}{3}}
+\@writefile{toc}{\contentsline {section}{\numberline {3}Wiring Pinout is wrong on Internet - Cable has labels}{3}}
+\@writefile{toc}{\contentsline {section}{\numberline {4}Arduino VReg Blowout}{3}}
+\@writefile{toc}{\contentsline {section}{\numberline {5}Amplifier}{3}}
+\@writefile{toc}{\contentsline {section}{\numberline {6}AC Audio Coupling to Remove DC Noise from Auto}{4}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {6.1}Ground Isolator}{4}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {6.2}Capacitor Audio Coupling}{4}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {6.2.1}Impedance / ESR of capacitors failing to pass enough power of signal}{5}}
+\@writefile{lof}{\contentsline {figure}{\numberline {2}{\ignorespaces Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.\relax }}{5}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {6.2.2}Wikipedia on Impedance}{5}}
+\citation{Scherz}
+\bibcite{Scherz}{1}
+\@writefile{toc}{\contentsline {section}{\numberline {7}DIY Amp}{6}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {7.1}LM383 is Obsolete}{6}}
+\@writefile{toc}{\contentsline {section}{\numberline {8}References}{6}}

Car_Stereo_Replacement/docs/13.log

@@ -0,0 +1,244 @@
+This is pdfTeX, Version 3.14159265-2.6-1.40.17 (TeX Live 2016/Debian) (preloaded format=pdflatex 2019.8.17)  19 FEB 2020 00:00
+entering extended mode
+ restricted \write18 enabled.
+ %&-line parsing enabled.
+**/home/layoutdev/Desktop/code/documentation_general/Electronics_Projects_2019/
+Car_Stereo_Replacement/docs/13.tex
+
+(/home/layoutdev/Desktop/code/documentation_general/Electronics_Projects_2019/C
+ar_Stereo_Replacement/docs/13.tex
+LaTeX2e <2017/01/01> patch level 3
+Babel <3.9r> and hyphenation patterns for 3 language(s) loaded.
+(/usr/share/texlive/texmf-dist/tex/latex/base/article.cls
+Document Class: article 2014/09/29 v1.4h Standard LaTeX document class
+(/usr/share/texlive/texmf-dist/tex/latex/base/size11.clo
+File: size11.clo 2014/09/29 v1.4h Standard LaTeX file (size option)
+)
+\c@part=\count79
+\c@section=\count80
+\c@subsection=\count81
+\c@subsubsection=\count82
+\c@paragraph=\count83
+\c@subparagraph=\count84
+\c@figure=\count85
+\c@table=\count86
+\abovecaptionskip=\skip41
+\belowcaptionskip=\skip42
+\bibindent=\dimen102
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/graphicx.sty
+Package: graphicx 2014/10/28 v1.0g Enhanced LaTeX Graphics (DPC,SPQR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/keyval.sty
+Package: keyval 2014/10/28 v1.15 key=value parser (DPC)
+\KV@toks@=\toks14
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/graphics.sty
+Package: graphics 2016/10/09 v1.0u Standard LaTeX Graphics (DPC,SPQR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/trig.sty
+Package: trig 2016/01/03 v1.10 sin cos tan (DPC)
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics-cfg/graphics.cfg
+File: graphics.cfg 2016/06/04 v1.11 sample graphics configuration
+)
+Package graphics Info: Driver file: pdftex.def on input line 99.
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics-def/pdftex.def
+File: pdftex.def 2017/01/12 v0.06k Graphics/color for pdfTeX
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/infwarerr.sty
+Package: infwarerr 2016/05/16 v1.4 Providing info/warning/error messages (HO)
+)
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ltxcmds.sty
+Package: ltxcmds 2016/05/16 v1.23 LaTeX kernel commands for general use (HO)
+)
+\Gread@gobject=\count87
+))
+\Gin@req@height=\dimen103
+\Gin@req@width=\dimen104
+)
+(/usr/share/texlive/texmf-dist/tex/latex/caption/caption.sty
+Package: caption 2016/02/21 v3.3-144 Customizing captions (AR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/caption/caption3.sty
+Package: caption3 2016/05/22 v1.7-166 caption3 kernel (AR)
+Package caption3 Info: TeX engine: e-TeX on input line 67.
+\captionmargin=\dimen105
+\captionmargin@=\dimen106
+\captionwidth=\dimen107
+\caption@tempdima=\dimen108
+\caption@indent=\dimen109
+\caption@parindent=\dimen110
+\caption@hangindent=\dimen111
+)
+\c@ContinuedFloat=\count88
+) (./13.aux)
+\openout1 = `13.aux'.
+
+LaTeX Font Info:    Checking defaults for OML/cmm/m/it on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for T1/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OT1/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OMS/cmsy/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OMX/cmex/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for U/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+
+(/usr/share/texlive/texmf-dist/tex/context/base/mkii/supp-pdf.mkii
+[Loading MPS to PDF converter (version 2006.09.02).]
+\scratchcounter=\count89
+\scratchdimen=\dimen112
+\scratchbox=\box26
+\nofMPsegments=\count90
+\nofMParguments=\count91
+\everyMPshowfont=\toks15
+\MPscratchCnt=\count92
+\MPscratchDim=\dimen113
+\MPnumerator=\count93
+\makeMPintoPDFobject=\count94
+\everyMPtoPDFconversion=\toks16
+) (/usr/share/texlive/texmf-dist/tex/generic/oberdiek/pdftexcmds.sty
+Package: pdftexcmds 2016/05/21 v0.22 Utility functions of pdfTeX for LuaTeX (HO
+)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ifluatex.sty
+Package: ifluatex 2016/05/16 v1.4 Provides the ifluatex switch (HO)
+Package ifluatex Info: LuaTeX not detected.
+)
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ifpdf.sty
+Package: ifpdf 2016/05/14 v3.1 Provides the ifpdf switch
+)
+Package pdftexcmds Info: LuaTeX not detected.
+Package pdftexcmds Info: \pdf@primitive is available.
+Package pdftexcmds Info: \pdf@ifprimitive is available.
+Package pdftexcmds Info: \pdfdraftmode found.
+)
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/epstopdf-base.sty
+Package: epstopdf-base 2016/05/15 v2.6 Base part for package epstopdf
+
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/grfext.sty
+Package: grfext 2016/05/16 v1.2 Manage graphics extensions (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/kvdefinekeys.sty
+Package: kvdefinekeys 2016/05/16 v1.4 Define keys (HO)
+))
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/kvoptions.sty
+Package: kvoptions 2016/05/16 v3.12 Key value format for package options (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/kvsetkeys.sty
+Package: kvsetkeys 2016/05/16 v1.17 Key value parser (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/etexcmds.sty
+Package: etexcmds 2016/05/16 v1.6 Avoid name clashes with e-TeX commands (HO)
+Package etexcmds Info: Could not find \expanded.
+(etexcmds)             That can mean that you are not using pdfTeX 1.50 or
+(etexcmds)             that some package has redefined \expanded.
+(etexcmds)             In the latter case, load this package earlier.
+)))
+Package epstopdf-base Info: Redefining graphics rule for `.eps' on input line 4
+38.
+Package grfext Info: Graphics extension search list:
+(grfext)             [.png,.pdf,.jpg,.mps,.jpeg,.jbig2,.jb2,.PNG,.PDF,.JPG,.JPE
+G,.JBIG2,.JB2,.eps]
+(grfext)             \AppendGraphicsExtensions on input line 456.
+
+(/usr/share/texlive/texmf-dist/tex/latex/latexconfig/epstopdf-sys.cfg
+File: epstopdf-sys.cfg 2010/07/13 v1.3 Configuration of (r)epstopdf for TeX Liv
+e
+))
+Package caption Info: Begin \AtBeginDocument code.
+Package caption Info: End \AtBeginDocument code.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <12> on input line 9.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <8> on input line 9.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <6> on input line 9.
+
+
+LaTeX Warning: No \author given.
+
+
+Underfull \hbox (badness 10000) in paragraph at lines 12--14
+
+ []
+
+<../pics/DSCN2180.JPG, id=1, 803.0pt x 602.25pt>
+File: ../pics/DSCN2180.JPG Graphic file (type jpg)
+ <use ../pics/DSCN2180.JPG>
+Package pdftex.def Info: ../pics/DSCN2180.JPG used on input line 15.
+(pdftex.def)             Requested size: 321.1943pt x 240.89572pt.
+
+
+Package caption Warning: \captionsetup{type*=...} or \captionof
+(caption)                outside box or environment on input line 16.
+See the caption package documentation for explanation.
+
+[1
+
+{/var/lib/texmf/fonts/map/pdftex/updmap/pdftex.map} <../pics/DSCN2180.JPG>]
+LaTeX Font Info:    Try loading font information for OMS+cmr on input line 21.
+
+(/usr/share/texlive/texmf-dist/tex/latex/base/omscmr.fd
+File: omscmr.fd 2014/09/29 v2.5h Standard LaTeX font definitions
+)
+LaTeX Font Info:    Font shape `OMS/cmr/m/n' in size <10.95> not available
+(Font)              Font shape `OMS/cmsy/m/n' tried instead on input line 21.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <10.95> on input line 30.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <9> on input line 30.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <5> on input line 30.
+
+Underfull \hbox (badness 10000) in paragraph at lines 46--47
+[]\OT1/cmr/m/n/10.95 https://thecavepearlproject.org/2019/02/25/no-parts-temper
+ature-
+ []
+
+[2] [3] [4]
+<../pics/esr_impedance_capacitance.png, id=24, 697.10437pt x 421.69917pt>
+File: ../pics/esr_impedance_capacitance.png Graphic file (type png)
+
+<use ../pics/esr_impedance_capacitance.png>
+Package pdftex.def Info: ../pics/esr_impedance_capacitance.png used on input li
+ne 75.
+(pdftex.def)             Requested size: 348.55133pt x 210.84906pt.
+
+Overfull \hbox (13.6647pt too wide) in paragraph at lines 83--83
+[] \OT1/cmtt/m/n/10.95 https://en.wikipedia.org/w/index.php\title=Aluminum_elec
+trolytic 
+ []
+
+[5 <../pics/esr_impedance_capacitance.png (PNG copy)>] [6] (./13.aux) ) 
+Here is how much of TeX's memory you used:
+ 2610 strings out of 494945
+ 41777 string characters out of 6181032
+ 96833 words of memory out of 5000000
+ 5895 multiletter control sequences out of 15000+600000
+ 10544 words of font info for 37 fonts, out of 8000000 for 9000
+ 14 hyphenation exceptions out of 8191
+ 39i,8n,39p,867b,229s stack positions out of 5000i,500n,10000p,200000b,80000s
+</usr/sh
+are/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmbx10.pfb></usr/share/te
+xlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmbx12.pfb></usr/share/texlive/
+texmf-dist/fonts/type1/public/amsfonts/cm/cmr10.pfb></usr/share/texlive/texmf-d
+ist/fonts/type1/public/amsfonts/cm/cmr12.pfb></usr/share/texlive/texmf-dist/fon
+ts/type1/public/amsfonts/cm/cmr6.pfb></usr/share/texlive/texmf-dist/fonts/type1
+/public/amsfonts/cm/cmr8.pfb></usr/share/texlive/texmf-dist/fonts/type1/public/
+amsfonts/cm/cmr9.pfb></usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts
+/cm/cmsy10.pfb></usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cm
+ti10.pfb></usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmtt10.p
+fb>
+Output written on 13.pdf (6 pages, 385023 bytes).
+PDF statistics:
+ 65 PDF objects out of 1000 (max. 8388607)
+ 44 compressed objects within 1 object stream
+ 0 named destinations out of 1000 (max. 500000)
+ 11 words of extra memory for PDF output out of 10000 (max. 10000000)
+

Car_Stereo_Replacement/docs/13.tex

@@ -0,0 +1,104 @@
+\documentclass[11pt]{article}
+%Gummi|065|=)
+\title{\textbf{Car Stereo Replacement}}
+\usepackage{graphicx,caption}
+%\author{Steak Electronics}
+\date{02/13/20}
+\begin{document}
+
+\maketitle
+
+\section{Overview}
+Replacing a car stereo. I could just go to ebay, and buy a used car stereo, but where's the fun in that? Let's DIY a car stereo from a PCB used as a frontplate, a connector for my vehicle, and an audio amplifier. I'll connect in signal from an audio player.
+\\
+
+\includegraphics[scale=0.4]{../pics/DSCN2180.JPG}
+\captionof{figure}{PCB rev 1}
+
+\section{Items Included}
+I thought I would include the following:
+\begin{itemize}
+\item Arduino Nano
+\item Voltage and Gnd Breakout
+\item I2C Display
+\item Voltage Readout (of BAT)
+\item Current Readout (being drawn)
+\item Amplifier ``Lvpin LP-838''
+\end{itemize}
+I also wanted to have the connectors that eurorack and synth designers use for mono audio cables, but the cables turned out too expensive. The current readout didn't work initially, and I haven't gotten to fixing it yet.
+\subsection{I2C OLED display}
+Just for fun, I bought an I2C oled display and am going to use it to display something.\footnote{It's an Arduino Uno, you can put almost anything on this.} Notes on this:
+Using the adafruit SSD1306 and GFX library (this procedure is well covered in other places), you can load an example sketch and get it running. First thing to change is to remove the Adafruit logo and replace it with my own. Let's do that.
+
+From https://design.goeszen.com/convert-image-for-oled-display.html
+\begin{verbatim}
+I'm on Linux here and found that the readily-available 
+ImageMagick package will do the trick for you without
+ any scripting. And runs on the CLI! Simple as that:
+
+    convert some_image.png some.image.mono
+\end{verbatim}
+That's efficient. But it didn't really work out. Too much work, I don't need it that bad. Have to convert it to something the c compiler can read. I instead, just deleted their logo. Good enough for now.
+\subsection{Internal AVR Temperature Sensor}
+
+I setup the code to read from the internal temp sensor on the duino. However there is also this:
+
+https://thecavepearlproject.org/2019/02/25/no-parts-temperature-measurement-with-arduino-pro-mini-to-0-005c-or-better/
+
+This would be something to do for more resolution. The built in sensor is not very good, so this above link would be great. Hack a day also covers it. 
+
+\section{Wiring Pinout is wrong on Internet - Cable has labels}
+I looked at the picture I have detailing the pinout of my car connector (Delco Delphi radio wiring diagram.jpg in resources). It's close, but not 100\% correct. I found that the cable itself has small text labels on each wire which explain which everything does. I didn't notice earlier, as I didn't look close enough (and no one mentioned this).
+
+\section{Arduino VReg Blowout}
+I had a knock off Arduino Nano, and the vreg blew out. I have some other vregs to replace it. I didn't have this problem with an Uno that I use as a ceiling dome light. Although that one is not left on as long, usually. 
+
+\section{Amplifier}
+The amplifier I used is one of the cheapest avialable on ebay. I'm not proud. I'm poor. I had to take it apart, and reseat the amplifier ICs as the tab was not making contact with the chassis for one of them. I also added thermal paste. This amp is underpowered for my car, and may need replacing. It gets a bit hot.
+
+Some other issues with this amplifier are that the output connectors can get pushed back, there is only one output connector option, and it must run on battery power, as a 12V 1A or 2A will not power it. Finally, there is a 6V DC bias on output. No output audio isolation, which means you get car noise.
+
+\section{AC Audio Coupling to Remove DC Noise from Auto}
+I had some fun with this one. Many videos on this in the video folder. I started with the speakers being directly fed by the amplifier. This worked, but there was some noise coming through. Cars are noisy, this is not surprising. I would've preferred the amplifier to isolate the outputs, but no luck... At this point, I considered two options to block DC and allow AC. 1) Use a transformer. 2) Use capacitors.\footnote{A third option would've been to use a second set of batteries, but that would be laborious.}
+
+\subsection{Ground Isolator}
+I had been given a Ground isolator, which was two small transformers on a pcb intended to pass audio from a car powered signal source into the car speakers. I tried this isolator on the output of the speakers, and while it worked, the volume was lower, and it was impractical. I knew as soon as I heard the volume, that the issue was an impedance matching problem. The transformers were too small. They were intended for signal sources, not amplifier outputs. Onto option \#2.
+
+\subsection{Capacitor Audio Coupling}
+My initial thoughts here were: ``Let's be careful and use non polarized caps''. I bought some 0.22uf and 0.022uf polyester film capacitors at Electronics Plus, the local radioshack replacement, and tried them. No sound. After adjusting the connectors on the amp (which were admittedly loose - it's easy to push them back on the amplifier if you are not careful) I found that the capacitors didn't work. One problem was evident in the oscope. I only used one capacitor on the + output of the speaker amp, but the Amp biases the signal 6 volts. So I needed two. After that was resolved, the signal came through on the output of the capacitor, as viewed on the scope, however there was no sound output. I tried the safe way. It's time to break some rules. 
+
+I grabbed some 1uf (electrolytic polarized) caps I had, and tried these. Again, no sound. Not giving up, I grabbed some 1000uf 'lytics, and tried once more. Now it worked.
+
+\subsubsection{Impedance / ESR of capacitors failing to pass enough power of signal}
+Capacitors are rated for impedance. Some data sheets also call this ESR, it appears after a quick look. It's either in there as impedance or ESR. It's not initially an issue if you are using the capacitor as a DC reservoir, but if you use it in an AC coupling situation then things get interesting. A high impedance, or ESR will block what a low one won't. In this example, it's as simple as the Amplfier either being able to power a speaker or not. Higher capacity caps will have lower impedance. See the picture. Other brands put impedance in a graph, or just call it impedance. 
+
+\includegraphics[scale=0.5]{../pics/esr_impedance_capacitance.png}
+\captionof{figure}{Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.}
+
+\subsubsection{Wikipedia on Impedance}
+
+\emph{In general, a capacitor is seen as a storage component for electric energy. But this is only one capacitor function. A capacitor can also act as an AC resistor. Especially aluminum electrolytic capacitors are used in many applications as a decoupling capacitors to filter or bypass undesired biased AC frequencies to the ground or for capacitive coupling of audio AC signals. Then the dielectric is used only for blocking DC. For such applications the AC resistance, the impedance is as important as the capacitance value. }
+\begin{verbatim} https://en.wikipedia.org/w/index.php\title=Aluminum_electrolytic
+_capacitor&oldid=940281525
+\end{verbatim}
+Essentially, what I learned today.
+
+\section{DIY Amp}
+I was flipping through Practical Electronics for Inventors\cite{Scherz}(page 959), when I came across an audio amplifier. He also gives one at the chapter on Semiconductors (pg. 467), although the former is more detailed. With a reasonably simple schematic available, and a high likelihood of it working, I say why not: let's build it up.
+
+I've noticed that the ``Lvpin LP-838'' amplifier I'm using is underpowered for my two front speakers \footnote{Although it seems it would work for one channel, so two of them might be enough. It's rated for 20W, so that is about 15-20W per channel req'd. It works at 20W for both, just that it heats up too much. Multiple ebay sellers have it misquoted at 200W. Just an extra 0, no biggie. Based on all this, it appears each channel of my car speaker needs about 15 watts to be on the safe side. The example schematic is 16 watts. Two should suffice.}, so I will make two of the provided 16 watt amps.
+
+\subsection{LM383 is Obsolete}
+That explains why I haven't heard of it. The chip is obsolete. Some sell it on ebay for about \$5 each.
+
+As a different route, could I use some other power amplifier op amp, with the same pinout? Hm...
+
+\section{References}
+\begin{thebibliography}{99}
+\bibitem{Scherz}
+  Paul Scherz, and Simon Monk,
+  \emph{Practical Electronics for Inventors}, fourth edition - 2016, McGraw Hill.
+
+  \end{thebibliography}
+
+\end{document}

Car_Stereo_Replacement/docs/14.aux

@@ -0,0 +1,20 @@
+\relax 
+\@writefile{toc}{\contentsline {section}{\numberline {1}Overview}{1}}
+\@writefile{lof}{\contentsline {figure}{\numberline {1}{\ignorespaces PCB rev 1\relax }}{1}}
+\@writefile{toc}{\contentsline {section}{\numberline {2}Items Included}{2}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {2.1}I2C OLED display}{2}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {2.2}Internal AVR Temperature Sensor}{3}}
+\@writefile{toc}{\contentsline {section}{\numberline {3}Wiring Pinout is wrong on Internet - Cable has labels}{3}}
+\@writefile{toc}{\contentsline {section}{\numberline {4}Arduino VReg Blowout}{3}}
+\@writefile{toc}{\contentsline {section}{\numberline {5}Amplifier}{3}}
+\@writefile{toc}{\contentsline {section}{\numberline {6}AC Audio Coupling to Remove DC Noise from Auto}{4}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {6.1}Ground Isolator}{4}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {6.2}Capacitor Audio Coupling}{4}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {6.2.1}Impedance / ESR of capacitors failing to pass enough power of signal}{5}}
+\@writefile{lof}{\contentsline {figure}{\numberline {2}{\ignorespaces Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.\relax }}{5}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {6.2.2}Wikipedia on Impedance}{5}}
+\citation{Scherz}
+\bibcite{Scherz}{1}
+\@writefile{toc}{\contentsline {section}{\numberline {7}DIY Amp}{6}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {7.1}LM383 is Obsolete}{6}}
+\@writefile{toc}{\contentsline {section}{\numberline {8}References}{7}}

Car_Stereo_Replacement/docs/14.log

@@ -0,0 +1,244 @@
+This is pdfTeX, Version 3.14159265-2.6-1.40.17 (TeX Live 2016/Debian) (preloaded format=pdflatex 2019.8.17)  19 FEB 2020 00:12
+entering extended mode
+ restricted \write18 enabled.
+ %&-line parsing enabled.
+**/home/layoutdev/Desktop/code/documentation_general/Electronics_Projects_2019/
+Car_Stereo_Replacement/docs/14.tex
+
+(/home/layoutdev/Desktop/code/documentation_general/Electronics_Projects_2019/C
+ar_Stereo_Replacement/docs/14.tex
+LaTeX2e <2017/01/01> patch level 3
+Babel <3.9r> and hyphenation patterns for 3 language(s) loaded.
+(/usr/share/texlive/texmf-dist/tex/latex/base/article.cls
+Document Class: article 2014/09/29 v1.4h Standard LaTeX document class
+(/usr/share/texlive/texmf-dist/tex/latex/base/size11.clo
+File: size11.clo 2014/09/29 v1.4h Standard LaTeX file (size option)
+)
+\c@part=\count79
+\c@section=\count80
+\c@subsection=\count81
+\c@subsubsection=\count82
+\c@paragraph=\count83
+\c@subparagraph=\count84
+\c@figure=\count85
+\c@table=\count86
+\abovecaptionskip=\skip41
+\belowcaptionskip=\skip42
+\bibindent=\dimen102
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/graphicx.sty
+Package: graphicx 2014/10/28 v1.0g Enhanced LaTeX Graphics (DPC,SPQR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/keyval.sty
+Package: keyval 2014/10/28 v1.15 key=value parser (DPC)
+\KV@toks@=\toks14
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/graphics.sty
+Package: graphics 2016/10/09 v1.0u Standard LaTeX Graphics (DPC,SPQR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/trig.sty
+Package: trig 2016/01/03 v1.10 sin cos tan (DPC)
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics-cfg/graphics.cfg
+File: graphics.cfg 2016/06/04 v1.11 sample graphics configuration
+)
+Package graphics Info: Driver file: pdftex.def on input line 99.
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics-def/pdftex.def
+File: pdftex.def 2017/01/12 v0.06k Graphics/color for pdfTeX
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/infwarerr.sty
+Package: infwarerr 2016/05/16 v1.4 Providing info/warning/error messages (HO)
+)
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ltxcmds.sty
+Package: ltxcmds 2016/05/16 v1.23 LaTeX kernel commands for general use (HO)
+)
+\Gread@gobject=\count87
+))
+\Gin@req@height=\dimen103
+\Gin@req@width=\dimen104
+)
+(/usr/share/texlive/texmf-dist/tex/latex/caption/caption.sty
+Package: caption 2016/02/21 v3.3-144 Customizing captions (AR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/caption/caption3.sty
+Package: caption3 2016/05/22 v1.7-166 caption3 kernel (AR)
+Package caption3 Info: TeX engine: e-TeX on input line 67.
+\captionmargin=\dimen105
+\captionmargin@=\dimen106
+\captionwidth=\dimen107
+\caption@tempdima=\dimen108
+\caption@indent=\dimen109
+\caption@parindent=\dimen110
+\caption@hangindent=\dimen111
+)
+\c@ContinuedFloat=\count88
+) (./14.aux)
+\openout1 = `14.aux'.
+
+LaTeX Font Info:    Checking defaults for OML/cmm/m/it on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for T1/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OT1/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OMS/cmsy/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OMX/cmex/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for U/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+
+(/usr/share/texlive/texmf-dist/tex/context/base/mkii/supp-pdf.mkii
+[Loading MPS to PDF converter (version 2006.09.02).]
+\scratchcounter=\count89
+\scratchdimen=\dimen112
+\scratchbox=\box26
+\nofMPsegments=\count90
+\nofMParguments=\count91
+\everyMPshowfont=\toks15
+\MPscratchCnt=\count92
+\MPscratchDim=\dimen113
+\MPnumerator=\count93
+\makeMPintoPDFobject=\count94
+\everyMPtoPDFconversion=\toks16
+) (/usr/share/texlive/texmf-dist/tex/generic/oberdiek/pdftexcmds.sty
+Package: pdftexcmds 2016/05/21 v0.22 Utility functions of pdfTeX for LuaTeX (HO
+)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ifluatex.sty
+Package: ifluatex 2016/05/16 v1.4 Provides the ifluatex switch (HO)
+Package ifluatex Info: LuaTeX not detected.
+)
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ifpdf.sty
+Package: ifpdf 2016/05/14 v3.1 Provides the ifpdf switch
+)
+Package pdftexcmds Info: LuaTeX not detected.
+Package pdftexcmds Info: \pdf@primitive is available.
+Package pdftexcmds Info: \pdf@ifprimitive is available.
+Package pdftexcmds Info: \pdfdraftmode found.
+)
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/epstopdf-base.sty
+Package: epstopdf-base 2016/05/15 v2.6 Base part for package epstopdf
+
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/grfext.sty
+Package: grfext 2016/05/16 v1.2 Manage graphics extensions (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/kvdefinekeys.sty
+Package: kvdefinekeys 2016/05/16 v1.4 Define keys (HO)
+))
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/kvoptions.sty
+Package: kvoptions 2016/05/16 v3.12 Key value format for package options (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/kvsetkeys.sty
+Package: kvsetkeys 2016/05/16 v1.17 Key value parser (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/etexcmds.sty
+Package: etexcmds 2016/05/16 v1.6 Avoid name clashes with e-TeX commands (HO)
+Package etexcmds Info: Could not find \expanded.
+(etexcmds)             That can mean that you are not using pdfTeX 1.50 or
+(etexcmds)             that some package has redefined \expanded.
+(etexcmds)             In the latter case, load this package earlier.
+)))
+Package epstopdf-base Info: Redefining graphics rule for `.eps' on input line 4
+38.
+Package grfext Info: Graphics extension search list:
+(grfext)             [.png,.pdf,.jpg,.mps,.jpeg,.jbig2,.jb2,.PNG,.PDF,.JPG,.JPE
+G,.JBIG2,.JB2,.eps]
+(grfext)             \AppendGraphicsExtensions on input line 456.
+
+(/usr/share/texlive/texmf-dist/tex/latex/latexconfig/epstopdf-sys.cfg
+File: epstopdf-sys.cfg 2010/07/13 v1.3 Configuration of (r)epstopdf for TeX Liv
+e
+))
+Package caption Info: Begin \AtBeginDocument code.
+Package caption Info: End \AtBeginDocument code.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <12> on input line 9.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <8> on input line 9.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <6> on input line 9.
+
+
+LaTeX Warning: No \author given.
+
+
+Underfull \hbox (badness 10000) in paragraph at lines 12--14
+
+ []
+
+<../pics/DSCN2180.JPG, id=1, 803.0pt x 602.25pt>
+File: ../pics/DSCN2180.JPG Graphic file (type jpg)
+ <use ../pics/DSCN2180.JPG>
+Package pdftex.def Info: ../pics/DSCN2180.JPG used on input line 15.
+(pdftex.def)             Requested size: 321.1943pt x 240.89572pt.
+
+
+Package caption Warning: \captionsetup{type*=...} or \captionof
+(caption)                outside box or environment on input line 16.
+See the caption package documentation for explanation.
+
+[1
+
+{/var/lib/texmf/fonts/map/pdftex/updmap/pdftex.map} <../pics/DSCN2180.JPG>]
+LaTeX Font Info:    Try loading font information for OMS+cmr on input line 21.
+
+(/usr/share/texlive/texmf-dist/tex/latex/base/omscmr.fd
+File: omscmr.fd 2014/09/29 v2.5h Standard LaTeX font definitions
+)
+LaTeX Font Info:    Font shape `OMS/cmr/m/n' in size <10.95> not available
+(Font)              Font shape `OMS/cmsy/m/n' tried instead on input line 21.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <10.95> on input line 30.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <9> on input line 30.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <5> on input line 30.
+
+Underfull \hbox (badness 10000) in paragraph at lines 46--47
+[]\OT1/cmr/m/n/10.95 https://thecavepearlproject.org/2019/02/25/no-parts-temper
+ature-
+ []
+
+[2] [3] [4]
+<../pics/esr_impedance_capacitance.png, id=24, 697.10437pt x 421.69917pt>
+File: ../pics/esr_impedance_capacitance.png Graphic file (type png)
+
+<use ../pics/esr_impedance_capacitance.png>
+Package pdftex.def Info: ../pics/esr_impedance_capacitance.png used on input li
+ne 75.
+(pdftex.def)             Requested size: 348.55133pt x 210.84906pt.
+
+Overfull \hbox (13.6647pt too wide) in paragraph at lines 83--83
+[] \OT1/cmtt/m/n/10.95 https://en.wikipedia.org/w/index.php\title=Aluminum_elec
+trolytic 
+ []
+
+[5 <../pics/esr_impedance_capacitance.png (PNG copy)>] [6] [7] (./14.aux) ) 
+Here is how much of TeX's memory you used:
+ 2610 strings out of 494945
+ 41777 string characters out of 6181032
+ 96833 words of memory out of 5000000
+ 5895 multiletter control sequences out of 15000+600000
+ 10544 words of font info for 37 fonts, out of 8000000 for 9000
+ 14 hyphenation exceptions out of 8191
+ 39i,8n,39p,867b,229s stack positions out of 5000i,500n,10000p,200000b,80000s
+</us
+r/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmbx10.pfb></usr/shar
+e/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmbx12.pfb></usr/share/texl
+ive/texmf-dist/fonts/type1/public/amsfonts/cm/cmr10.pfb></usr/share/texlive/tex
+mf-dist/fonts/type1/public/amsfonts/cm/cmr12.pfb></usr/share/texlive/texmf-dist
+/fonts/type1/public/amsfonts/cm/cmr6.pfb></usr/share/texlive/texmf-dist/fonts/t
+ype1/public/amsfonts/cm/cmr8.pfb></usr/share/texlive/texmf-dist/fonts/type1/pub
+lic/amsfonts/cm/cmr9.pfb></usr/share/texlive/texmf-dist/fonts/type1/public/amsf
+onts/cm/cmsy10.pfb></usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/c
+m/cmti10.pfb></usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmtt
+10.pfb>
+Output written on 14.pdf (7 pages, 388737 bytes).
+PDF statistics:
+ 70 PDF objects out of 1000 (max. 8388607)
+ 48 compressed objects within 1 object stream
+ 0 named destinations out of 1000 (max. 500000)
+ 11 words of extra memory for PDF output out of 10000 (max. 10000000)
+

Car_Stereo_Replacement/docs/14.tex

@@ -0,0 +1,108 @@
+\documentclass[11pt]{article}
+%Gummi|065|=)
+\title{\textbf{Car Stereo Replacement}}
+\usepackage{graphicx,caption}
+%\author{Steak Electronics}
+\date{02/13/20}
+\begin{document}
+
+\maketitle
+
+\section{Overview}
+Replacing a car stereo. I could just go to ebay, and buy a used car stereo, but where's the fun in that? Let's DIY a car stereo from a PCB used as a frontplate, a connector for my vehicle, and an audio amplifier. I'll connect in signal from an audio player.
+\\
+
+\includegraphics[scale=0.4]{../pics/DSCN2180.JPG}
+\captionof{figure}{PCB rev 1}
+
+\section{Items Included}
+I thought I would include the following:
+\begin{itemize}
+\item Arduino Nano
+\item Voltage and Gnd Breakout
+\item I2C Display
+\item Voltage Readout (of BAT)
+\item Current Readout (being drawn)
+\item Amplifier ``Lvpin LP-838''
+\end{itemize}
+I also wanted to have the connectors that eurorack and synth designers use for mono audio cables, but the cables turned out too expensive. The current readout didn't work initially, and I haven't gotten to fixing it yet.
+\subsection{I2C OLED display}
+Just for fun, I bought an I2C oled display and am going to use it to display something.\footnote{It's an Arduino Uno, you can put almost anything on this.} Notes on this:
+Using the adafruit SSD1306 and GFX library (this procedure is well covered in other places), you can load an example sketch and get it running. First thing to change is to remove the Adafruit logo and replace it with my own. Let's do that.
+
+From https://design.goeszen.com/convert-image-for-oled-display.html
+\begin{verbatim}
+I'm on Linux here and found that the readily-available 
+ImageMagick package will do the trick for you without
+ any scripting. And runs on the CLI! Simple as that:
+
+    convert some_image.png some.image.mono
+\end{verbatim}
+That's efficient. But it didn't really work out. Too much work, I don't need it that bad. Have to convert it to something the c compiler can read. I instead, just deleted their logo. Good enough for now.
+\subsection{Internal AVR Temperature Sensor}
+
+I setup the code to read from the internal temp sensor on the duino. However there is also this:
+
+https://thecavepearlproject.org/2019/02/25/no-parts-temperature-measurement-with-arduino-pro-mini-to-0-005c-or-better/
+
+This would be something to do for more resolution. The built in sensor is not very good, so this above link would be great. Hack a day also covers it. 
+
+\section{Wiring Pinout is wrong on Internet - Cable has labels}
+I looked at the picture I have detailing the pinout of my car connector (Delco Delphi radio wiring diagram.jpg in resources). It's close, but not 100\% correct. I found that the cable itself has small text labels on each wire which explain which everything does. I didn't notice earlier, as I didn't look close enough (and no one mentioned this).
+
+\section{Arduino VReg Blowout}
+I had a knock off Arduino Nano, and the vreg blew out. I have some other vregs to replace it. I didn't have this problem with an Uno that I use as a ceiling dome light. Although that one is not left on as long, usually. 
+
+\section{Amplifier}
+The amplifier I used is one of the cheapest avialable on ebay. I'm not proud. I'm poor. I had to take it apart, and reseat the amplifier ICs as the tab was not making contact with the chassis for one of them. I also added thermal paste. This amp is underpowered for my car, and may need replacing. It gets a bit hot.
+
+Some other issues with this amplifier are that the output connectors can get pushed back, there is only one output connector option, and it must run on battery power, as a 12V 1A or 2A will not power it. Finally, there is a 6V DC bias on output. No output audio isolation, which means you get car noise.
+
+\section{AC Audio Coupling to Remove DC Noise from Auto}
+I had some fun with this one. Many videos on this in the video folder. I started with the speakers being directly fed by the amplifier. This worked, but there was some noise coming through. Cars are noisy, this is not surprising. I would've preferred the amplifier to isolate the outputs, but no luck... At this point, I considered two options to block DC and allow AC. 1) Use a transformer. 2) Use capacitors.\footnote{A third option would've been to use a second set of batteries, but that would be laborious.}
+
+\subsection{Ground Isolator}
+I had been given a Ground isolator, which was two small transformers on a pcb intended to pass audio from a car powered signal source into the car speakers. I tried this isolator on the output of the speakers, and while it worked, the volume was lower, and it was impractical. I knew as soon as I heard the volume, that the issue was an impedance matching problem. The transformers were too small. They were intended for signal sources, not amplifier outputs. Onto option \#2.
+
+\subsection{Capacitor Audio Coupling}
+My initial thoughts here were: ``Let's be careful and use non polarized caps''. I bought some 0.22uf and 0.022uf polyester film capacitors at Electronics Plus, the local radioshack replacement, and tried them. No sound. After adjusting the connectors on the amp (which were admittedly loose - it's easy to push them back on the amplifier if you are not careful) I found that the capacitors didn't work. One problem was evident in the oscope. I only used one capacitor on the + output of the speaker amp, but the Amp biases the signal 6 volts. So I needed two. After that was resolved, the signal came through on the output of the capacitor, as viewed on the scope, however there was no sound output. I tried the safe way. It's time to break some rules. 
+
+I grabbed some 1uf (electrolytic polarized) caps I had, and tried these. Again, no sound. Not giving up, I grabbed some 1000uf 'lytics, and tried once more. Now it worked.
+
+\subsubsection{Impedance / ESR of capacitors failing to pass enough power of signal}
+Capacitors are rated for impedance. Some data sheets also call this ESR, it appears after a quick look. It's either in there as impedance or ESR. It's not initially an issue if you are using the capacitor as a DC reservoir, but if you use it in an AC coupling situation then things get interesting. A high impedance, or ESR will block what a low one won't. In this example, it's as simple as the Amplfier either being able to power a speaker or not. Higher capacity caps will have lower impedance. See the picture. Other brands put impedance in a graph, or just call it impedance. 
+
+\includegraphics[scale=0.5]{../pics/esr_impedance_capacitance.png}
+\captionof{figure}{Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.}
+
+\subsubsection{Wikipedia on Impedance}
+
+\emph{In general, a capacitor is seen as a storage component for electric energy. But this is only one capacitor function. A capacitor can also act as an AC resistor. Especially aluminum electrolytic capacitors are used in many applications as a decoupling capacitors to filter or bypass undesired biased AC frequencies to the ground or for capacitive coupling of audio AC signals. Then the dielectric is used only for blocking DC. For such applications the AC resistance, the impedance is as important as the capacitance value. }
+\begin{verbatim} https://en.wikipedia.org/w/index.php\title=Aluminum_electrolytic
+_capacitor&oldid=940281525
+\end{verbatim}
+Essentially, what I learned today.
+
+\section{DIY Amp}
+I was flipping through Practical Electronics for Inventors\cite{Scherz}(page 959), when I came across an audio amplifier. He also gives one at the chapter on Semiconductors (pg. 467), although the former is more detailed. With a reasonably simple schematic available, and a high likelihood of it working, I say why not: let's build it up.
+
+I've noticed that the ``Lvpin LP-838'' amplifier I'm using is underpowered for my two front speakers \footnote{Although it seems it would work for one channel, so two of them might be enough. It's rated for 20W, so that is about 15-20W per channel req'd. It works at 20W for both, just that it heats up too much. Multiple ebay sellers have it misquoted at 200W. Just an extra 0, no biggie. Based on all this, it appears each channel of my car speaker needs about 15 watts to be on the safe side. The example schematic is 16 watts. Two should suffice.}, so I will make two of the provided 16 watt amps.
+
+\subsection{LM383 is Obsolete}
+That explains why I haven't heard of it. The chip is obsolete. Some sell it on ebay for about \$5 each.
+
+As a different route, could I use some other power amplifier op amp, with the same pinout? Hm... Aha, the LM1875 has the same pinout. Let's use that.\footnote{How did I find this? I searched Digikey for the LM383 sold by rochester, noted it was it the category of Linear - Amplifiers - Audio, chose that, then searched for everything in the same package (TO220-5). Came right up. If this hadn't worked, I would've wanted to try other sites: Farnells, Mouser, etc...}
+
+Will it work with the same schematic? Questionable. May still need to buy a LM383, along with the LM1875, as backup. Amplfiers are expensive bom item here.
+
+ 
+
+\section{References}
+\begin{thebibliography}{99}
+\bibitem{Scherz}
+  Paul Scherz, and Simon Monk,
+  \emph{Practical Electronics for Inventors}, fourth edition - 2016, McGraw Hill.
+
+  \end{thebibliography}
+
+\end{document}

Car_Stereo_Replacement/docs/14.tex~

@@ -0,0 +1,107 @@
+\documentclass[11pt]{article}
+%Gummi|065|=)
+\title{\textbf{Car Stereo Replacement}}
+\usepackage{graphicx,caption}
+%\author{Steak Electronics}
+\date{02/13/20}
+\begin{document}
+
+\maketitle
+
+\section{Overview}
+Replacing a car stereo. I could just go to ebay, and buy a used car stereo, but where's the fun in that? Let's DIY a car stereo from a PCB used as a frontplate, a connector for my vehicle, and an audio amplifier. I'll connect in signal from an audio player.
+\\
+
+\includegraphics[scale=0.4]{../pics/DSCN2180.JPG}
+\captionof{figure}{PCB rev 1}
+
+\section{Items Included}
+I thought I would include the following:
+\begin{itemize}
+\item Arduino Nano
+\item Voltage and Gnd Breakout
+\item I2C Display
+\item Voltage Readout (of BAT)
+\item Current Readout (being drawn)
+\item Amplifier ``Lvpin LP-838''
+\end{itemize}
+I also wanted to have the connectors that eurorack and synth designers use for mono audio cables, but the cables turned out too expensive. The current readout didn't work initially, and I haven't gotten to fixing it yet.
+\subsection{I2C OLED display}
+Just for fun, I bought an I2C oled display and am going to use it to display something.\footnote{It's an Arduino Uno, you can put almost anything on this.} Notes on this:
+Using the adafruit SSD1306 and GFX library (this procedure is well covered in other places), you can load an example sketch and get it running. First thing to change is to remove the Adafruit logo and replace it with my own. Let's do that.
+
+From https://design.goeszen.com/convert-image-for-oled-display.html
+\begin{verbatim}
+I'm on Linux here and found that the readily-available 
+ImageMagick package will do the trick for you without
+ any scripting. And runs on the CLI! Simple as that:
+
+    convert some_image.png some.image.mono
+\end{verbatim}
+That's efficient. But it didn't really work out. Too much work, I don't need it that bad. Have to convert it to something the c compiler can read. I instead, just deleted their logo. Good enough for now.
+\subsection{Internal AVR Temperature Sensor}
+
+I setup the code to read from the internal temp sensor on the duino. However there is also this:
+
+https://thecavepearlproject.org/2019/02/25/no-parts-temperature-measurement-with-arduino-pro-mini-to-0-005c-or-better/
+
+This would be something to do for more resolution. The built in sensor is not very good, so this above link would be great. Hack a day also covers it. 
+
+\section{Wiring Pinout is wrong on Internet - Cable has labels}
+I looked at the picture I have detailing the pinout of my car connector (Delco Delphi radio wiring diagram.jpg in resources). It's close, but not 100\% correct. I found that the cable itself has small text labels on each wire which explain which everything does. I didn't notice earlier, as I didn't look close enough (and no one mentioned this).
+
+\section{Arduino VReg Blowout}
+I had a knock off Arduino Nano, and the vreg blew out. I have some other vregs to replace it. I didn't have this problem with an Uno that I use as a ceiling dome light. Although that one is not left on as long, usually. 
+
+\section{Amplifier}
+The amplifier I used is one of the cheapest avialable on ebay. I'm not proud. I'm poor. I had to take it apart, and reseat the amplifier ICs as the tab was not making contact with the chassis for one of them. I also added thermal paste. This amp is underpowered for my car, and may need replacing. It gets a bit hot.
+
+Some other issues with this amplifier are that the output connectors can get pushed back, there is only one output connector option, and it must run on battery power, as a 12V 1A or 2A will not power it. Finally, there is a 6V DC bias on output. No output audio isolation, which means you get car noise.
+
+\section{AC Audio Coupling to Remove DC Noise from Auto}
+I had some fun with this one. Many videos on this in the video folder. I started with the speakers being directly fed by the amplifier. This worked, but there was some noise coming through. Cars are noisy, this is not surprising. I would've preferred the amplifier to isolate the outputs, but no luck... At this point, I considered two options to block DC and allow AC. 1) Use a transformer. 2) Use capacitors.\footnote{A third option would've been to use a second set of batteries, but that would be laborious.}
+
+\subsection{Ground Isolator}
+I had been given a Ground isolator, which was two small transformers on a pcb intended to pass audio from a car powered signal source into the car speakers. I tried this isolator on the output of the speakers, and while it worked, the volume was lower, and it was impractical. I knew as soon as I heard the volume, that the issue was an impedance matching problem. The transformers were too small. They were intended for signal sources, not amplifier outputs. Onto option \#2.
+
+\subsection{Capacitor Audio Coupling}
+My initial thoughts here were: ``Let's be careful and use non polarized caps''. I bought some 0.22uf and 0.022uf polyester film capacitors at Electronics Plus, the local radioshack replacement, and tried them. No sound. After adjusting the connectors on the amp (which were admittedly loose - it's easy to push them back on the amplifier if you are not careful) I found that the capacitors didn't work. One problem was evident in the oscope. I only used one capacitor on the + output of the speaker amp, but the Amp biases the signal 6 volts. So I needed two. After that was resolved, the signal came through on the output of the capacitor, as viewed on the scope, however there was no sound output. I tried the safe way. It's time to break some rules. 
+
+I grabbed some 1uf (electrolytic polarized) caps I had, and tried these. Again, no sound. Not giving up, I grabbed some 1000uf 'lytics, and tried once more. Now it worked.
+
+\subsubsection{Impedance / ESR of capacitors failing to pass enough power of signal}
+Capacitors are rated for impedance. Some data sheets also call this ESR, it appears after a quick look. It's either in there as impedance or ESR. It's not initially an issue if you are using the capacitor as a DC reservoir, but if you use it in an AC coupling situation then things get interesting. A high impedance, or ESR will block what a low one won't. In this example, it's as simple as the Amplfier either being able to power a speaker or not. Higher capacity caps will have lower impedance. See the picture. Other brands put impedance in a graph, or just call it impedance. 
+
+\includegraphics[scale=0.5]{../pics/esr_impedance_capacitance.png}
+\captionof{figure}{Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.}
+
+\subsubsection{Wikipedia on Impedance}
+
+\emph{In general, a capacitor is seen as a storage component for electric energy. But this is only one capacitor function. A capacitor can also act as an AC resistor. Especially aluminum electrolytic capacitors are used in many applications as a decoupling capacitors to filter or bypass undesired biased AC frequencies to the ground or for capacitive coupling of audio AC signals. Then the dielectric is used only for blocking DC. For such applications the AC resistance, the impedance is as important as the capacitance value. }
+\begin{verbatim} https://en.wikipedia.org/w/index.php\title=Aluminum_electrolytic
+_capacitor&oldid=940281525
+\end{verbatim}
+Essentially, what I learned today.
+
+\section{DIY Amp}
+I was flipping through Practical Electronics for Inventors\cite{Scherz}(page 959), when I came across an audio amplifier. He also gives one at the chapter on Semiconductors (pg. 467), although the former is more detailed. With a reasonably simple schematic available, and a high likelihood of it working, I say why not: let's build it up.
+
+I've noticed that the ``Lvpin LP-838'' amplifier I'm using is underpowered for my two front speakers \footnote{Although it seems it would work for one channel, so two of them might be enough. It's rated for 20W, so that is about 15-20W per channel req'd. It works at 20W for both, just that it heats up too much. Multiple ebay sellers have it misquoted at 200W. Just an extra 0, no biggie. Based on all this, it appears each channel of my car speaker needs about 15 watts to be on the safe side. The example schematic is 16 watts. Two should suffice.}, so I will make two of the provided 16 watt amps.
+
+\subsection{LM383 is Obsolete}
+That explains why I haven't heard of it. The chip is obsolete. Some sell it on ebay for about \$5 each.
+
+As a different route, could I use some other power amplifier op amp, with the same pinout? Hm... Aha, the LM1875 has the same pinout. Let's use that.\footnote{How did I find this? I searched Digikey for the LM383 sold by rochester, noted it was it the category of Linear - Amplifiers - Audio, chose that, then searched for everything in the same package (TO220-5). Came right up.
+
+
+ 
+
+\section{References}
+\begin{thebibliography}{99}
+\bibitem{Scherz}
+  Paul Scherz, and Simon Monk,
+  \emph{Practical Electronics for Inventors}, fourth edition - 2016, McGraw Hill.
+
+  \end{thebibliography}
+
+\end{document}

Car_Stereo_Replacement/docs/15.aux

@@ -0,0 +1,20 @@
+\relax 
+\@writefile{toc}{\contentsline {section}{\numberline {1}Overview}{1}}
+\@writefile{lof}{\contentsline {figure}{\numberline {1}{\ignorespaces PCB rev 1\relax }}{1}}
+\@writefile{toc}{\contentsline {section}{\numberline {2}Items Included}{2}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {2.1}I2C OLED display}{2}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {2.2}Internal AVR Temperature Sensor}{3}}
+\@writefile{toc}{\contentsline {section}{\numberline {3}Wiring Pinout is wrong on Internet - Cable has labels}{3}}
+\@writefile{toc}{\contentsline {section}{\numberline {4}Arduino VReg Blowout}{3}}
+\@writefile{toc}{\contentsline {section}{\numberline {5}Amplifier}{3}}
+\@writefile{toc}{\contentsline {section}{\numberline {6}AC Audio Coupling to Remove DC Noise from Auto}{4}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {6.1}Ground Isolator}{4}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {6.2}Capacitor Audio Coupling}{4}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {6.2.1}Impedance / ESR of capacitors failing to pass enough power of signal}{5}}
+\@writefile{lof}{\contentsline {figure}{\numberline {2}{\ignorespaces Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.\relax }}{5}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {6.2.2}Wikipedia on Impedance}{5}}
+\citation{Scherz}
+\bibcite{Scherz}{1}
+\@writefile{toc}{\contentsline {section}{\numberline {7}DIY Amp}{6}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {7.1}LM383 is Obsolete}{6}}
+\@writefile{toc}{\contentsline {section}{\numberline {8}References}{7}}

Car_Stereo_Replacement/docs/15.log

@@ -0,0 +1,244 @@
+This is pdfTeX, Version 3.14159265-2.6-1.40.17 (TeX Live 2016/Debian) (preloaded format=pdflatex 2019.8.17)  21 FEB 2020 01:01
+entering extended mode
+ restricted \write18 enabled.
+ %&-line parsing enabled.
+**/home/layoutdev/Desktop/code/documentation_general/Electronics_Projects_2019/
+Car_Stereo_Replacement/docs/15.tex
+
+(/home/layoutdev/Desktop/code/documentation_general/Electronics_Projects_2019/C
+ar_Stereo_Replacement/docs/15.tex
+LaTeX2e <2017/01/01> patch level 3
+Babel <3.9r> and hyphenation patterns for 3 language(s) loaded.
+(/usr/share/texlive/texmf-dist/tex/latex/base/article.cls
+Document Class: article 2014/09/29 v1.4h Standard LaTeX document class
+(/usr/share/texlive/texmf-dist/tex/latex/base/size11.clo
+File: size11.clo 2014/09/29 v1.4h Standard LaTeX file (size option)
+)
+\c@part=\count79
+\c@section=\count80
+\c@subsection=\count81
+\c@subsubsection=\count82
+\c@paragraph=\count83
+\c@subparagraph=\count84
+\c@figure=\count85
+\c@table=\count86
+\abovecaptionskip=\skip41
+\belowcaptionskip=\skip42
+\bibindent=\dimen102
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/graphicx.sty
+Package: graphicx 2014/10/28 v1.0g Enhanced LaTeX Graphics (DPC,SPQR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/keyval.sty
+Package: keyval 2014/10/28 v1.15 key=value parser (DPC)
+\KV@toks@=\toks14
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/graphics.sty
+Package: graphics 2016/10/09 v1.0u Standard LaTeX Graphics (DPC,SPQR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/trig.sty
+Package: trig 2016/01/03 v1.10 sin cos tan (DPC)
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics-cfg/graphics.cfg
+File: graphics.cfg 2016/06/04 v1.11 sample graphics configuration
+)
+Package graphics Info: Driver file: pdftex.def on input line 99.
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics-def/pdftex.def
+File: pdftex.def 2017/01/12 v0.06k Graphics/color for pdfTeX
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/infwarerr.sty
+Package: infwarerr 2016/05/16 v1.4 Providing info/warning/error messages (HO)
+)
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ltxcmds.sty
+Package: ltxcmds 2016/05/16 v1.23 LaTeX kernel commands for general use (HO)
+)
+\Gread@gobject=\count87
+))
+\Gin@req@height=\dimen103
+\Gin@req@width=\dimen104
+)
+(/usr/share/texlive/texmf-dist/tex/latex/caption/caption.sty
+Package: caption 2016/02/21 v3.3-144 Customizing captions (AR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/caption/caption3.sty
+Package: caption3 2016/05/22 v1.7-166 caption3 kernel (AR)
+Package caption3 Info: TeX engine: e-TeX on input line 67.
+\captionmargin=\dimen105
+\captionmargin@=\dimen106
+\captionwidth=\dimen107
+\caption@tempdima=\dimen108
+\caption@indent=\dimen109
+\caption@parindent=\dimen110
+\caption@hangindent=\dimen111
+)
+\c@ContinuedFloat=\count88
+) (./15.aux)
+\openout1 = `15.aux'.
+
+LaTeX Font Info:    Checking defaults for OML/cmm/m/it on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for T1/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OT1/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OMS/cmsy/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OMX/cmex/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for U/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+
+(/usr/share/texlive/texmf-dist/tex/context/base/mkii/supp-pdf.mkii
+[Loading MPS to PDF converter (version 2006.09.02).]
+\scratchcounter=\count89
+\scratchdimen=\dimen112
+\scratchbox=\box26
+\nofMPsegments=\count90
+\nofMParguments=\count91
+\everyMPshowfont=\toks15
+\MPscratchCnt=\count92
+\MPscratchDim=\dimen113
+\MPnumerator=\count93
+\makeMPintoPDFobject=\count94
+\everyMPtoPDFconversion=\toks16
+) (/usr/share/texlive/texmf-dist/tex/generic/oberdiek/pdftexcmds.sty
+Package: pdftexcmds 2016/05/21 v0.22 Utility functions of pdfTeX for LuaTeX (HO
+)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ifluatex.sty
+Package: ifluatex 2016/05/16 v1.4 Provides the ifluatex switch (HO)
+Package ifluatex Info: LuaTeX not detected.
+)
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ifpdf.sty
+Package: ifpdf 2016/05/14 v3.1 Provides the ifpdf switch
+)
+Package pdftexcmds Info: LuaTeX not detected.
+Package pdftexcmds Info: \pdf@primitive is available.
+Package pdftexcmds Info: \pdf@ifprimitive is available.
+Package pdftexcmds Info: \pdfdraftmode found.
+)
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/epstopdf-base.sty
+Package: epstopdf-base 2016/05/15 v2.6 Base part for package epstopdf
+
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/grfext.sty
+Package: grfext 2016/05/16 v1.2 Manage graphics extensions (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/kvdefinekeys.sty
+Package: kvdefinekeys 2016/05/16 v1.4 Define keys (HO)
+))
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/kvoptions.sty
+Package: kvoptions 2016/05/16 v3.12 Key value format for package options (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/kvsetkeys.sty
+Package: kvsetkeys 2016/05/16 v1.17 Key value parser (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/etexcmds.sty
+Package: etexcmds 2016/05/16 v1.6 Avoid name clashes with e-TeX commands (HO)
+Package etexcmds Info: Could not find \expanded.
+(etexcmds)             That can mean that you are not using pdfTeX 1.50 or
+(etexcmds)             that some package has redefined \expanded.
+(etexcmds)             In the latter case, load this package earlier.
+)))
+Package epstopdf-base Info: Redefining graphics rule for `.eps' on input line 4
+38.
+Package grfext Info: Graphics extension search list:
+(grfext)             [.png,.pdf,.jpg,.mps,.jpeg,.jbig2,.jb2,.PNG,.PDF,.JPG,.JPE
+G,.JBIG2,.JB2,.eps]
+(grfext)             \AppendGraphicsExtensions on input line 456.
+
+(/usr/share/texlive/texmf-dist/tex/latex/latexconfig/epstopdf-sys.cfg
+File: epstopdf-sys.cfg 2010/07/13 v1.3 Configuration of (r)epstopdf for TeX Liv
+e
+))
+Package caption Info: Begin \AtBeginDocument code.
+Package caption Info: End \AtBeginDocument code.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <12> on input line 9.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <8> on input line 9.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <6> on input line 9.
+
+
+LaTeX Warning: No \author given.
+
+
+Underfull \hbox (badness 10000) in paragraph at lines 12--14
+
+ []
+
+<../pics/DSCN2180.JPG, id=1, 803.0pt x 602.25pt>
+File: ../pics/DSCN2180.JPG Graphic file (type jpg)
+ <use ../pics/DSCN2180.JPG>
+Package pdftex.def Info: ../pics/DSCN2180.JPG used on input line 15.
+(pdftex.def)             Requested size: 321.1943pt x 240.89572pt.
+
+
+Package caption Warning: \captionsetup{type*=...} or \captionof
+(caption)                outside box or environment on input line 16.
+See the caption package documentation for explanation.
+
+[1
+
+{/var/lib/texmf/fonts/map/pdftex/updmap/pdftex.map} <../pics/DSCN2180.JPG>]
+LaTeX Font Info:    Try loading font information for OMS+cmr on input line 21.
+
+(/usr/share/texlive/texmf-dist/tex/latex/base/omscmr.fd
+File: omscmr.fd 2014/09/29 v2.5h Standard LaTeX font definitions
+)
+LaTeX Font Info:    Font shape `OMS/cmr/m/n' in size <10.95> not available
+(Font)              Font shape `OMS/cmsy/m/n' tried instead on input line 21.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <10.95> on input line 30.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <9> on input line 30.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <5> on input line 30.
+
+Underfull \hbox (badness 10000) in paragraph at lines 46--47
+[]\OT1/cmr/m/n/10.95 https://thecavepearlproject.org/2019/02/25/no-parts-temper
+ature-
+ []
+
+[2] [3] [4]
+<../pics/esr_impedance_capacitance.png, id=24, 697.10437pt x 421.69917pt>
+File: ../pics/esr_impedance_capacitance.png Graphic file (type png)
+
+<use ../pics/esr_impedance_capacitance.png>
+Package pdftex.def Info: ../pics/esr_impedance_capacitance.png used on input li
+ne 75.
+(pdftex.def)             Requested size: 348.55133pt x 210.84906pt.
+
+Overfull \hbox (13.6647pt too wide) in paragraph at lines 83--83
+[] \OT1/cmtt/m/n/10.95 https://en.wikipedia.org/w/index.php\title=Aluminum_elec
+trolytic 
+ []
+
+[5 <../pics/esr_impedance_capacitance.png (PNG copy)>] [6] [7] (./15.aux) ) 
+Here is how much of TeX's memory you used:
+ 2610 strings out of 494945
+ 41777 string characters out of 6181032
+ 96833 words of memory out of 5000000
+ 5895 multiletter control sequences out of 15000+600000
+ 10544 words of font info for 37 fonts, out of 8000000 for 9000
+ 14 hyphenation exceptions out of 8191
+ 39i,8n,39p,867b,229s stack positions out of 5000i,500n,10000p,200000b,80000s
+</us
+r/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmbx10.pfb></usr/shar
+e/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmbx12.pfb></usr/share/texl
+ive/texmf-dist/fonts/type1/public/amsfonts/cm/cmr10.pfb></usr/share/texlive/tex
+mf-dist/fonts/type1/public/amsfonts/cm/cmr12.pfb></usr/share/texlive/texmf-dist
+/fonts/type1/public/amsfonts/cm/cmr6.pfb></usr/share/texlive/texmf-dist/fonts/t
+ype1/public/amsfonts/cm/cmr8.pfb></usr/share/texlive/texmf-dist/fonts/type1/pub
+lic/amsfonts/cm/cmr9.pfb></usr/share/texlive/texmf-dist/fonts/type1/public/amsf
+onts/cm/cmsy10.pfb></usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/c
+m/cmti10.pfb></usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmtt
+10.pfb>
+Output written on 15.pdf (7 pages, 388776 bytes).
+PDF statistics:
+ 70 PDF objects out of 1000 (max. 8388607)
+ 48 compressed objects within 1 object stream
+ 0 named destinations out of 1000 (max. 500000)
+ 11 words of extra memory for PDF output out of 10000 (max. 10000000)
+

Car_Stereo_Replacement/docs/15.tex

@@ -0,0 +1,110 @@
+\documentclass[11pt]{article}
+%Gummi|065|=)
+\title{\textbf{Car Stereo Replacement}}
+\usepackage{graphicx,caption}
+%\author{Steak Electronics}
+\date{02/13/20}
+\begin{document}
+
+\maketitle
+
+\section{Overview}
+Replacing a car stereo. I could just go to ebay, and buy a used car stereo, but where's the fun in that? Let's DIY a car stereo from a PCB used as a frontplate, a connector for my vehicle, and an audio amplifier. I'll connect in signal from an audio player.
+\\
+
+\includegraphics[scale=0.4]{../pics/DSCN2180.JPG}
+\captionof{figure}{PCB rev 1}
+
+\section{Items Included}
+I thought I would include the following:
+\begin{itemize}
+\item Arduino Nano
+\item Voltage and Gnd Breakout
+\item I2C Display
+\item Voltage Readout (of BAT)
+\item Current Readout (being drawn)
+\item Amplifier ``Lvpin LP-838''
+\end{itemize}
+I also wanted to have the connectors that eurorack and synth designers use for mono audio cables, but the cables turned out too expensive. The current readout didn't work initially, and I haven't gotten to fixing it yet.
+\subsection{I2C OLED display}
+Just for fun, I bought an I2C oled display and am going to use it to display something.\footnote{It's an Arduino Uno, you can put almost anything on this.} Notes on this:
+Using the adafruit SSD1306 and GFX library (this procedure is well covered in other places), you can load an example sketch and get it running. First thing to change is to remove the Adafruit logo and replace it with my own. Let's do that.
+
+From https://design.goeszen.com/convert-image-for-oled-display.html
+\begin{verbatim}
+I'm on Linux here and found that the readily-available 
+ImageMagick package will do the trick for you without
+ any scripting. And runs on the CLI! Simple as that:
+
+    convert some_image.png some.image.mono
+\end{verbatim}
+That's efficient. But it didn't really work out. Too much work, I don't need it that bad. Have to convert it to something the c compiler can read. I instead, just deleted their logo. Good enough for now.
+\subsection{Internal AVR Temperature Sensor}
+
+I setup the code to read from the internal temp sensor on the duino. However there is also this:
+
+https://thecavepearlproject.org/2019/02/25/no-parts-temperature-measurement-with-arduino-pro-mini-to-0-005c-or-better/
+
+This would be something to do for more resolution. The built in sensor is not very good, so this above link would be great. Hack a day also covers it. 
+
+\section{Wiring Pinout is wrong on Internet - Cable has labels}
+I looked at the picture I have detailing the pinout of my car connector (Delco Delphi radio wiring diagram.jpg in resources). It's close, but not 100\% correct. I found that the cable itself has small text labels on each wire which explain which everything does. I didn't notice earlier, as I didn't look close enough (and no one mentioned this).
+
+\section{Arduino VReg Blowout}
+I had a knock off Arduino Nano, and the vreg blew out. I have some other vregs to replace it. I didn't have this problem with an Uno that I use as a ceiling dome light. Although that one is not left on as long, usually. 
+
+\section{Amplifier}
+The amplifier I used is one of the cheapest avialable on ebay. I'm not proud. I'm poor. I had to take it apart, and reseat the amplifier ICs as the tab was not making contact with the chassis for one of them. I also added thermal paste. This amp is underpowered for my car, and may need replacing. It gets a bit hot.
+
+Some other issues with this amplifier are that the output connectors can get pushed back, there is only one output connector option, and it must run on battery power, as a 12V 1A or 2A will not power it. Finally, there is a 6V DC bias on output. No output audio isolation, which means you get car noise.
+
+\section{AC Audio Coupling to Remove DC Noise from Auto}
+I had some fun with this one. Many videos on this in the video folder. I started with the speakers being directly fed by the amplifier. This worked, but there was some noise coming through. Cars are noisy, this is not surprising. I would've preferred the amplifier to isolate the outputs, but no luck... At this point, I considered two options to block DC and allow AC. 1) Use a transformer. 2) Use capacitors.\footnote{A third option would've been to use a second set of batteries, but that would be laborious.}
+
+\subsection{Ground Isolator}
+I had been given a Ground isolator, which was two small transformers on a pcb intended to pass audio from a car powered signal source into the car speakers. I tried this isolator on the output of the speakers, and while it worked, the volume was lower, and it was impractical. I knew as soon as I heard the volume, that the issue was an impedance matching problem. The transformers were too small. They were intended for signal sources, not amplifier outputs. Onto option \#2.
+
+\subsection{Capacitor Audio Coupling}
+My initial thoughts here were: ``Let's be careful and use non polarized caps''. I bought some 0.22uf and 0.022uf polyester film capacitors at Electronics Plus, the local radioshack replacement, and tried them. No sound. After adjusting the connectors on the amp (which were admittedly loose - it's easy to push them back on the amplifier if you are not careful) I found that the capacitors didn't work. One problem was evident in the oscope. I only used one capacitor on the + output of the speaker amp, but the Amp biases the signal 6 volts. So I needed two. After that was resolved, the signal came through on the output of the capacitor, as viewed on the scope, however there was no sound output. I tried the safe way. It's time to break some rules. 
+
+I grabbed some 1uf (electrolytic polarized) caps I had, and tried these. Again, no sound. Not giving up, I grabbed some 1000uf 'lytics, and tried once more. Now it worked.
+
+\subsubsection{Impedance / ESR of capacitors failing to pass enough power of signal}
+Capacitors are rated for impedance. Some data sheets also call this ESR, it appears after a quick look. It's either in there as impedance or ESR. It's not initially an issue if you are using the capacitor as a DC reservoir, but if you use it in an AC coupling situation then things get interesting. A high impedance, or ESR will block what a low one won't. In this example, it's as simple as the Amplfier either being able to power a speaker or not. Higher capacity caps will have lower impedance. See the picture. Other brands put impedance in a graph, or just call it impedance. 
+
+\includegraphics[scale=0.5]{../pics/esr_impedance_capacitance.png}
+\captionof{figure}{Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.}
+
+\subsubsection{Wikipedia on Impedance}
+
+\emph{In general, a capacitor is seen as a storage component for electric energy. But this is only one capacitor function. A capacitor can also act as an AC resistor. Especially aluminum electrolytic capacitors are used in many applications as a decoupling capacitors to filter or bypass undesired biased AC frequencies to the ground or for capacitive coupling of audio AC signals. Then the dielectric is used only for blocking DC. For such applications the AC resistance, the impedance is as important as the capacitance value. }
+\begin{verbatim} https://en.wikipedia.org/w/index.php\title=Aluminum_electrolytic
+_capacitor&oldid=940281525
+\end{verbatim}
+Essentially, what I learned today.
+
+\section{DIY Amp}
+I was flipping through Practical Electronics for Inventors\cite{Scherz}(page 959), when I came across an audio amplifier. He also gives one at the chapter on Semiconductors (pg. 467), although the former is more detailed. With a reasonably simple schematic available, and a high likelihood of it working, I say why not: let's build it up.
+
+I've noticed that the ``Lvpin LP-838'' amplifier I'm using is underpowered for my two front speakers \footnote{Although it seems it would work for one channel, so two of them might be enough. It's rated for 20W, so that is about 15-20W per channel req'd. It works at 20W for both, just that it heats up too much. Multiple ebay sellers have it misquoted at 200W. Just an extra 0, no biggie. Based on all this, it appears each channel of my car speaker needs about 15 watts to be on the safe side. The example schematic is 16 watts. Two should suffice.}, so I will make two of the provided 16 watt amps.
+
+\subsection{LM383 is Obsolete}
+That explains why I haven't heard of it. The chip is obsolete. Some sell it on ebay for about \$5 each.
+
+As a different route, could I use some other power amplifier op amp, with the same pinout? Hm... Aha, the LM1875 has the same pinout. Let's use that.\footnote{How did I find this? I searched Digikey for the LM383 sold by rochester, noted it was it the category of Linear - Amplifiers - Audio, chose that, then searched for everything in the same package (TO220-5). Came right up. If this hadn't worked, I would've wanted to try other sites: Farnells, Mouser, etc...}
+
+Will it work with the same schematic? Questionable. May still need to buy a LM383, along with the LM1875, as backup. I might also try a generic power op amp.
+
+Amplfiers are the expensive bom item here.
+
+ 
+
+\section{References}
+\begin{thebibliography}{99}
+\bibitem{Scherz}
+  Paul Scherz, and Simon Monk,
+  \emph{Practical Electronics for Inventors}, fourth edition - 2016, McGraw Hill.
+
+  \end{thebibliography}
+
+\end{document}

Car_Stereo_Replacement/docs/15.tex~

@@ -0,0 +1,108 @@
+\documentclass[11pt]{article}
+%Gummi|065|=)
+\title{\textbf{Car Stereo Replacement}}
+\usepackage{graphicx,caption}
+%\author{Steak Electronics}
+\date{02/13/20}
+\begin{document}
+
+\maketitle
+
+\section{Overview}
+Replacing a car stereo. I could just go to ebay, and buy a used car stereo, but where's the fun in that? Let's DIY a car stereo from a PCB used as a frontplate, a connector for my vehicle, and an audio amplifier. I'll connect in signal from an audio player.
+\\
+
+\includegraphics[scale=0.4]{../pics/DSCN2180.JPG}
+\captionof{figure}{PCB rev 1}
+
+\section{Items Included}
+I thought I would include the following:
+\begin{itemize}
+\item Arduino Nano
+\item Voltage and Gnd Breakout
+\item I2C Display
+\item Voltage Readout (of BAT)
+\item Current Readout (being drawn)
+\item Amplifier ``Lvpin LP-838''
+\end{itemize}
+I also wanted to have the connectors that eurorack and synth designers use for mono audio cables, but the cables turned out too expensive. The current readout didn't work initially, and I haven't gotten to fixing it yet.
+\subsection{I2C OLED display}
+Just for fun, I bought an I2C oled display and am going to use it to display something.\footnote{It's an Arduino Uno, you can put almost anything on this.} Notes on this:
+Using the adafruit SSD1306 and GFX library (this procedure is well covered in other places), you can load an example sketch and get it running. First thing to change is to remove the Adafruit logo and replace it with my own. Let's do that.
+
+From https://design.goeszen.com/convert-image-for-oled-display.html
+\begin{verbatim}
+I'm on Linux here and found that the readily-available 
+ImageMagick package will do the trick for you without
+ any scripting. And runs on the CLI! Simple as that:
+
+    convert some_image.png some.image.mono
+\end{verbatim}
+That's efficient. But it didn't really work out. Too much work, I don't need it that bad. Have to convert it to something the c compiler can read. I instead, just deleted their logo. Good enough for now.
+\subsection{Internal AVR Temperature Sensor}
+
+I setup the code to read from the internal temp sensor on the duino. However there is also this:
+
+https://thecavepearlproject.org/2019/02/25/no-parts-temperature-measurement-with-arduino-pro-mini-to-0-005c-or-better/
+
+This would be something to do for more resolution. The built in sensor is not very good, so this above link would be great. Hack a day also covers it. 
+
+\section{Wiring Pinout is wrong on Internet - Cable has labels}
+I looked at the picture I have detailing the pinout of my car connector (Delco Delphi radio wiring diagram.jpg in resources). It's close, but not 100\% correct. I found that the cable itself has small text labels on each wire which explain which everything does. I didn't notice earlier, as I didn't look close enough (and no one mentioned this).
+
+\section{Arduino VReg Blowout}
+I had a knock off Arduino Nano, and the vreg blew out. I have some other vregs to replace it. I didn't have this problem with an Uno that I use as a ceiling dome light. Although that one is not left on as long, usually. 
+
+\section{Amplifier}
+The amplifier I used is one of the cheapest avialable on ebay. I'm not proud. I'm poor. I had to take it apart, and reseat the amplifier ICs as the tab was not making contact with the chassis for one of them. I also added thermal paste. This amp is underpowered for my car, and may need replacing. It gets a bit hot.
+
+Some other issues with this amplifier are that the output connectors can get pushed back, there is only one output connector option, and it must run on battery power, as a 12V 1A or 2A will not power it. Finally, there is a 6V DC bias on output. No output audio isolation, which means you get car noise.
+
+\section{AC Audio Coupling to Remove DC Noise from Auto}
+I had some fun with this one. Many videos on this in the video folder. I started with the speakers being directly fed by the amplifier. This worked, but there was some noise coming through. Cars are noisy, this is not surprising. I would've preferred the amplifier to isolate the outputs, but no luck... At this point, I considered two options to block DC and allow AC. 1) Use a transformer. 2) Use capacitors.\footnote{A third option would've been to use a second set of batteries, but that would be laborious.}
+
+\subsection{Ground Isolator}
+I had been given a Ground isolator, which was two small transformers on a pcb intended to pass audio from a car powered signal source into the car speakers. I tried this isolator on the output of the speakers, and while it worked, the volume was lower, and it was impractical. I knew as soon as I heard the volume, that the issue was an impedance matching problem. The transformers were too small. They were intended for signal sources, not amplifier outputs. Onto option \#2.
+
+\subsection{Capacitor Audio Coupling}
+My initial thoughts here were: ``Let's be careful and use non polarized caps''. I bought some 0.22uf and 0.022uf polyester film capacitors at Electronics Plus, the local radioshack replacement, and tried them. No sound. After adjusting the connectors on the amp (which were admittedly loose - it's easy to push them back on the amplifier if you are not careful) I found that the capacitors didn't work. One problem was evident in the oscope. I only used one capacitor on the + output of the speaker amp, but the Amp biases the signal 6 volts. So I needed two. After that was resolved, the signal came through on the output of the capacitor, as viewed on the scope, however there was no sound output. I tried the safe way. It's time to break some rules. 
+
+I grabbed some 1uf (electrolytic polarized) caps I had, and tried these. Again, no sound. Not giving up, I grabbed some 1000uf 'lytics, and tried once more. Now it worked.
+
+\subsubsection{Impedance / ESR of capacitors failing to pass enough power of signal}
+Capacitors are rated for impedance. Some data sheets also call this ESR, it appears after a quick look. It's either in there as impedance or ESR. It's not initially an issue if you are using the capacitor as a DC reservoir, but if you use it in an AC coupling situation then things get interesting. A high impedance, or ESR will block what a low one won't. In this example, it's as simple as the Amplfier either being able to power a speaker or not. Higher capacity caps will have lower impedance. See the picture. Other brands put impedance in a graph, or just call it impedance. 
+
+\includegraphics[scale=0.5]{../pics/esr_impedance_capacitance.png}
+\captionof{figure}{Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.}
+
+\subsubsection{Wikipedia on Impedance}
+
+\emph{In general, a capacitor is seen as a storage component for electric energy. But this is only one capacitor function. A capacitor can also act as an AC resistor. Especially aluminum electrolytic capacitors are used in many applications as a decoupling capacitors to filter or bypass undesired biased AC frequencies to the ground or for capacitive coupling of audio AC signals. Then the dielectric is used only for blocking DC. For such applications the AC resistance, the impedance is as important as the capacitance value. }
+\begin{verbatim} https://en.wikipedia.org/w/index.php\title=Aluminum_electrolytic
+_capacitor&oldid=940281525
+\end{verbatim}
+Essentially, what I learned today.
+
+\section{DIY Amp}
+I was flipping through Practical Electronics for Inventors\cite{Scherz}(page 959), when I came across an audio amplifier. He also gives one at the chapter on Semiconductors (pg. 467), although the former is more detailed. With a reasonably simple schematic available, and a high likelihood of it working, I say why not: let's build it up.
+
+I've noticed that the ``Lvpin LP-838'' amplifier I'm using is underpowered for my two front speakers \footnote{Although it seems it would work for one channel, so two of them might be enough. It's rated for 20W, so that is about 15-20W per channel req'd. It works at 20W for both, just that it heats up too much. Multiple ebay sellers have it misquoted at 200W. Just an extra 0, no biggie. Based on all this, it appears each channel of my car speaker needs about 15 watts to be on the safe side. The example schematic is 16 watts. Two should suffice.}, so I will make two of the provided 16 watt amps.
+
+\subsection{LM383 is Obsolete}
+That explains why I haven't heard of it. The chip is obsolete. Some sell it on ebay for about \$5 each.
+
+As a different route, could I use some other power amplifier op amp, with the same pinout? Hm... Aha, the LM1875 has the same pinout. Let's use that.\footnote{How did I find this? I searched Digikey for the LM383 sold by rochester, noted it was it the category of Linear - Amplifiers - Audio, chose that, then searched for everything in the same package (TO220-5). Came right up. If this hadn't worked, I would've wanted to try other sites: Farnells, Mouser, etc...}
+
+Will it work with the same schematic? Questionable. May still need to buy a LM383, along with the LM1875, as backup. Amplfiers are expensive bom item here.
+
+ 
+
+\section{References}
+\begin{thebibliography}{99}
+\bibitem{Scherz}
+  Paul Scherz, and Simon Monk,
+  \emph{Practical Electronics for Inventors}, fourth edition - 2016, McGraw Hill.
+
+  \end{thebibliography}
+
+\end{document}

Car_Stereo_Replacement/docs/16.aux

@@ -0,0 +1,20 @@
+\relax 
+\@writefile{toc}{\contentsline {section}{\numberline {1}Overview}{1}}
+\@writefile{lof}{\contentsline {figure}{\numberline {1}{\ignorespaces PCB rev 1\relax }}{1}}
+\@writefile{toc}{\contentsline {section}{\numberline {2}Items Included}{2}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {2.1}I2C OLED display}{2}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {2.2}Internal AVR Temperature Sensor}{3}}
+\@writefile{toc}{\contentsline {section}{\numberline {3}Wiring Pinout is wrong on Internet - Cable has labels}{3}}
+\@writefile{toc}{\contentsline {section}{\numberline {4}Arduino VReg Blowout}{3}}
+\@writefile{toc}{\contentsline {section}{\numberline {5}Amplifier}{3}}
+\@writefile{toc}{\contentsline {section}{\numberline {6}AC Audio Coupling to Remove DC Noise from Auto}{4}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {6.1}Ground Isolator}{4}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {6.2}Capacitor Audio Coupling}{4}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {6.2.1}Impedance / ESR of capacitors failing to pass enough power of signal}{5}}
+\@writefile{lof}{\contentsline {figure}{\numberline {2}{\ignorespaces Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.\relax }}{5}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {6.2.2}Wikipedia on Impedance}{5}}
+\citation{Scherz}
+\bibcite{Scherz}{1}
+\@writefile{toc}{\contentsline {section}{\numberline {7}DIY Amp}{6}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {7.1}LM383 is Obsolete}{6}}
+\@writefile{toc}{\contentsline {section}{\numberline {8}References}{7}}

Car_Stereo_Replacement/docs/16.log

@@ -0,0 +1,244 @@
+This is pdfTeX, Version 3.14159265-2.6-1.40.17 (TeX Live 2016/Debian) (preloaded format=pdflatex 2019.8.17)  21 FEB 2020 01:01
+entering extended mode
+ restricted \write18 enabled.
+ %&-line parsing enabled.
+**/home/layoutdev/Desktop/code/documentation_general/Electronics_Projects_2019/
+Car_Stereo_Replacement/docs/16.tex
+
+(/home/layoutdev/Desktop/code/documentation_general/Electronics_Projects_2019/C
+ar_Stereo_Replacement/docs/16.tex
+LaTeX2e <2017/01/01> patch level 3
+Babel <3.9r> and hyphenation patterns for 3 language(s) loaded.
+(/usr/share/texlive/texmf-dist/tex/latex/base/article.cls
+Document Class: article 2014/09/29 v1.4h Standard LaTeX document class
+(/usr/share/texlive/texmf-dist/tex/latex/base/size11.clo
+File: size11.clo 2014/09/29 v1.4h Standard LaTeX file (size option)
+)
+\c@part=\count79
+\c@section=\count80
+\c@subsection=\count81
+\c@subsubsection=\count82
+\c@paragraph=\count83
+\c@subparagraph=\count84
+\c@figure=\count85
+\c@table=\count86
+\abovecaptionskip=\skip41
+\belowcaptionskip=\skip42
+\bibindent=\dimen102
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/graphicx.sty
+Package: graphicx 2014/10/28 v1.0g Enhanced LaTeX Graphics (DPC,SPQR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/keyval.sty
+Package: keyval 2014/10/28 v1.15 key=value parser (DPC)
+\KV@toks@=\toks14
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/graphics.sty
+Package: graphics 2016/10/09 v1.0u Standard LaTeX Graphics (DPC,SPQR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/trig.sty
+Package: trig 2016/01/03 v1.10 sin cos tan (DPC)
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics-cfg/graphics.cfg
+File: graphics.cfg 2016/06/04 v1.11 sample graphics configuration
+)
+Package graphics Info: Driver file: pdftex.def on input line 99.
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics-def/pdftex.def
+File: pdftex.def 2017/01/12 v0.06k Graphics/color for pdfTeX
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/infwarerr.sty
+Package: infwarerr 2016/05/16 v1.4 Providing info/warning/error messages (HO)
+)
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ltxcmds.sty
+Package: ltxcmds 2016/05/16 v1.23 LaTeX kernel commands for general use (HO)
+)
+\Gread@gobject=\count87
+))
+\Gin@req@height=\dimen103
+\Gin@req@width=\dimen104
+)
+(/usr/share/texlive/texmf-dist/tex/latex/caption/caption.sty
+Package: caption 2016/02/21 v3.3-144 Customizing captions (AR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/caption/caption3.sty
+Package: caption3 2016/05/22 v1.7-166 caption3 kernel (AR)
+Package caption3 Info: TeX engine: e-TeX on input line 67.
+\captionmargin=\dimen105
+\captionmargin@=\dimen106
+\captionwidth=\dimen107
+\caption@tempdima=\dimen108
+\caption@indent=\dimen109
+\caption@parindent=\dimen110
+\caption@hangindent=\dimen111
+)
+\c@ContinuedFloat=\count88
+) (./16.aux)
+\openout1 = `16.aux'.
+
+LaTeX Font Info:    Checking defaults for OML/cmm/m/it on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for T1/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OT1/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OMS/cmsy/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OMX/cmex/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for U/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+
+(/usr/share/texlive/texmf-dist/tex/context/base/mkii/supp-pdf.mkii
+[Loading MPS to PDF converter (version 2006.09.02).]
+\scratchcounter=\count89
+\scratchdimen=\dimen112
+\scratchbox=\box26
+\nofMPsegments=\count90
+\nofMParguments=\count91
+\everyMPshowfont=\toks15
+\MPscratchCnt=\count92
+\MPscratchDim=\dimen113
+\MPnumerator=\count93
+\makeMPintoPDFobject=\count94
+\everyMPtoPDFconversion=\toks16
+) (/usr/share/texlive/texmf-dist/tex/generic/oberdiek/pdftexcmds.sty
+Package: pdftexcmds 2016/05/21 v0.22 Utility functions of pdfTeX for LuaTeX (HO
+)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ifluatex.sty
+Package: ifluatex 2016/05/16 v1.4 Provides the ifluatex switch (HO)
+Package ifluatex Info: LuaTeX not detected.
+)
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ifpdf.sty
+Package: ifpdf 2016/05/14 v3.1 Provides the ifpdf switch
+)
+Package pdftexcmds Info: LuaTeX not detected.
+Package pdftexcmds Info: \pdf@primitive is available.
+Package pdftexcmds Info: \pdf@ifprimitive is available.
+Package pdftexcmds Info: \pdfdraftmode found.
+)
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/epstopdf-base.sty
+Package: epstopdf-base 2016/05/15 v2.6 Base part for package epstopdf
+
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/grfext.sty
+Package: grfext 2016/05/16 v1.2 Manage graphics extensions (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/kvdefinekeys.sty
+Package: kvdefinekeys 2016/05/16 v1.4 Define keys (HO)
+))
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/kvoptions.sty
+Package: kvoptions 2016/05/16 v3.12 Key value format for package options (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/kvsetkeys.sty
+Package: kvsetkeys 2016/05/16 v1.17 Key value parser (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/etexcmds.sty
+Package: etexcmds 2016/05/16 v1.6 Avoid name clashes with e-TeX commands (HO)
+Package etexcmds Info: Could not find \expanded.
+(etexcmds)             That can mean that you are not using pdfTeX 1.50 or
+(etexcmds)             that some package has redefined \expanded.
+(etexcmds)             In the latter case, load this package earlier.
+)))
+Package epstopdf-base Info: Redefining graphics rule for `.eps' on input line 4
+38.
+Package grfext Info: Graphics extension search list:
+(grfext)             [.png,.pdf,.jpg,.mps,.jpeg,.jbig2,.jb2,.PNG,.PDF,.JPG,.JPE
+G,.JBIG2,.JB2,.eps]
+(grfext)             \AppendGraphicsExtensions on input line 456.
+
+(/usr/share/texlive/texmf-dist/tex/latex/latexconfig/epstopdf-sys.cfg
+File: epstopdf-sys.cfg 2010/07/13 v1.3 Configuration of (r)epstopdf for TeX Liv
+e
+))
+Package caption Info: Begin \AtBeginDocument code.
+Package caption Info: End \AtBeginDocument code.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <12> on input line 9.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <8> on input line 9.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <6> on input line 9.
+
+
+LaTeX Warning: No \author given.
+
+
+Underfull \hbox (badness 10000) in paragraph at lines 12--14
+
+ []
+
+<../pics/DSCN2180.JPG, id=1, 803.0pt x 602.25pt>
+File: ../pics/DSCN2180.JPG Graphic file (type jpg)
+ <use ../pics/DSCN2180.JPG>
+Package pdftex.def Info: ../pics/DSCN2180.JPG used on input line 15.
+(pdftex.def)             Requested size: 321.1943pt x 240.89572pt.
+
+
+Package caption Warning: \captionsetup{type*=...} or \captionof
+(caption)                outside box or environment on input line 16.
+See the caption package documentation for explanation.
+
+[1
+
+{/var/lib/texmf/fonts/map/pdftex/updmap/pdftex.map} <../pics/DSCN2180.JPG>]
+LaTeX Font Info:    Try loading font information for OMS+cmr on input line 21.
+
+(/usr/share/texlive/texmf-dist/tex/latex/base/omscmr.fd
+File: omscmr.fd 2014/09/29 v2.5h Standard LaTeX font definitions
+)
+LaTeX Font Info:    Font shape `OMS/cmr/m/n' in size <10.95> not available
+(Font)              Font shape `OMS/cmsy/m/n' tried instead on input line 21.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <10.95> on input line 30.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <9> on input line 30.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <5> on input line 30.
+
+Underfull \hbox (badness 10000) in paragraph at lines 46--47
+[]\OT1/cmr/m/n/10.95 https://thecavepearlproject.org/2019/02/25/no-parts-temper
+ature-
+ []
+
+[2] [3] [4]
+<../pics/esr_impedance_capacitance.png, id=24, 697.10437pt x 421.69917pt>
+File: ../pics/esr_impedance_capacitance.png Graphic file (type png)
+
+<use ../pics/esr_impedance_capacitance.png>
+Package pdftex.def Info: ../pics/esr_impedance_capacitance.png used on input li
+ne 75.
+(pdftex.def)             Requested size: 348.55133pt x 210.84906pt.
+
+Overfull \hbox (13.6647pt too wide) in paragraph at lines 83--83
+[] \OT1/cmtt/m/n/10.95 https://en.wikipedia.org/w/index.php\title=Aluminum_elec
+trolytic 
+ []
+
+[5 <../pics/esr_impedance_capacitance.png (PNG copy)>] [6] [7] (./16.aux) ) 
+Here is how much of TeX's memory you used:
+ 2610 strings out of 494945
+ 41777 string characters out of 6181032
+ 96833 words of memory out of 5000000
+ 5895 multiletter control sequences out of 15000+600000
+ 10544 words of font info for 37 fonts, out of 8000000 for 9000
+ 14 hyphenation exceptions out of 8191
+ 39i,8n,39p,867b,229s stack positions out of 5000i,500n,10000p,200000b,80000s
+</us
+r/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmbx10.pfb></usr/shar
+e/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmbx12.pfb></usr/share/texl
+ive/texmf-dist/fonts/type1/public/amsfonts/cm/cmr10.pfb></usr/share/texlive/tex
+mf-dist/fonts/type1/public/amsfonts/cm/cmr12.pfb></usr/share/texlive/texmf-dist
+/fonts/type1/public/amsfonts/cm/cmr6.pfb></usr/share/texlive/texmf-dist/fonts/t
+ype1/public/amsfonts/cm/cmr8.pfb></usr/share/texlive/texmf-dist/fonts/type1/pub
+lic/amsfonts/cm/cmr9.pfb></usr/share/texlive/texmf-dist/fonts/type1/public/amsf
+onts/cm/cmsy10.pfb></usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/c
+m/cmti10.pfb></usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmtt
+10.pfb>
+Output written on 16.pdf (7 pages, 388776 bytes).
+PDF statistics:
+ 70 PDF objects out of 1000 (max. 8388607)
+ 48 compressed objects within 1 object stream
+ 0 named destinations out of 1000 (max. 500000)
+ 11 words of extra memory for PDF output out of 10000 (max. 10000000)
+

Car_Stereo_Replacement/docs/16.tex

@@ -0,0 +1,110 @@
+\documentclass[11pt]{article}
+%Gummi|065|=)
+\title{\textbf{Car Stereo Replacement}}
+\usepackage{graphicx,caption}
+%\author{Steak Electronics}
+\date{02/13/20}
+\begin{document}
+
+\maketitle
+
+\section{Overview}
+Replacing a car stereo. I could just go to ebay, and buy a used car stereo, but where's the fun in that? Let's DIY a car stereo from a PCB used as a frontplate, a connector for my vehicle, and an audio amplifier. I'll connect in signal from an audio player.
+\\
+
+\includegraphics[scale=0.4]{../pics/DSCN2180.JPG}
+\captionof{figure}{PCB rev 1}
+
+\section{Items Included}
+I thought I would include the following:
+\begin{itemize}
+\item Arduino Nano
+\item Voltage and Gnd Breakout
+\item I2C Display
+\item Voltage Readout (of BAT)
+\item Current Readout (being drawn)
+\item Amplifier ``Lvpin LP-838''
+\end{itemize}
+I also wanted to have the connectors that eurorack and synth designers use for mono audio cables, but the cables turned out too expensive. The current readout didn't work initially, and I haven't gotten to fixing it yet.
+\subsection{I2C OLED display}
+Just for fun, I bought an I2C oled display and am going to use it to display something.\footnote{It's an Arduino Uno, you can put almost anything on this.} Notes on this:
+Using the adafruit SSD1306 and GFX library (this procedure is well covered in other places), you can load an example sketch and get it running. First thing to change is to remove the Adafruit logo and replace it with my own. Let's do that.
+
+From https://design.goeszen.com/convert-image-for-oled-display.html
+\begin{verbatim}
+I'm on Linux here and found that the readily-available 
+ImageMagick package will do the trick for you without
+ any scripting. And runs on the CLI! Simple as that:
+
+    convert some_image.png some.image.mono
+\end{verbatim}
+That's efficient. But it didn't really work out. Too much work, I don't need it that bad. Have to convert it to something the c compiler can read. I instead, just deleted their logo. Good enough for now.
+\subsection{Internal AVR Temperature Sensor}
+
+I setup the code to read from the internal temp sensor on the duino. However there is also this:
+
+https://thecavepearlproject.org/2019/02/25/no-parts-temperature-measurement-with-arduino-pro-mini-to-0-005c-or-better/
+
+This would be something to do for more resolution. The built in sensor is not very good, so this above link would be great. Hack a day also covers it. 
+
+\section{Wiring Pinout is wrong on Internet - Cable has labels}
+I looked at the picture I have detailing the pinout of my car connector (Delco Delphi radio wiring diagram.jpg in resources). It's close, but not 100\% correct. I found that the cable itself has small text labels on each wire which explain which everything does. I didn't notice earlier, as I didn't look close enough (and no one mentioned this).
+
+\section{Arduino VReg Blowout}
+I had a knock off Arduino Nano, and the vreg blew out. I have some other vregs to replace it. I didn't have this problem with an Uno that I use as a ceiling dome light. Although that one is not left on as long, usually. 
+
+\section{Amplifier}
+The amplifier I used is one of the cheapest avialable on ebay. I'm not proud. I'm poor. I had to take it apart, and reseat the amplifier ICs as the tab was not making contact with the chassis for one of them. I also added thermal paste. This amp is underpowered for my car, and may need replacing. It gets a bit hot.
+
+Some other issues with this amplifier are that the output connectors can get pushed back, there is only one output connector option, and it must run on battery power, as a 12V 1A or 2A will not power it. Finally, there is a 6V DC bias on output. No output audio isolation, which means you get car noise.
+
+\section{AC Audio Coupling to Remove DC Noise from Auto}
+I had some fun with this one. Many videos on this in the video folder. I started with the speakers being directly fed by the amplifier. This worked, but there was some noise coming through. Cars are noisy, this is not surprising. I would've preferred the amplifier to isolate the outputs, but no luck... At this point, I considered two options to block DC and allow AC. 1) Use a transformer. 2) Use capacitors.\footnote{A third option would've been to use a second set of batteries, but that would be laborious.}
+
+\subsection{Ground Isolator}
+I had been given a Ground isolator, which was two small transformers on a pcb intended to pass audio from a car powered signal source into the car speakers. I tried this isolator on the output of the speakers, and while it worked, the volume was lower, and it was impractical. I knew as soon as I heard the volume, that the issue was an impedance matching problem. The transformers were too small. They were intended for signal sources, not amplifier outputs. Onto option \#2.
+
+\subsection{Capacitor Audio Coupling}
+My initial thoughts here were: ``Let's be careful and use non polarized caps''. I bought some 0.22uf and 0.022uf polyester film capacitors at Electronics Plus, the local radioshack replacement, and tried them. No sound. After adjusting the connectors on the amp (which were admittedly loose - it's easy to push them back on the amplifier if you are not careful) I found that the capacitors didn't work. One problem was evident in the oscope. I only used one capacitor on the + output of the speaker amp, but the Amp biases the signal 6 volts. So I needed two. After that was resolved, the signal came through on the output of the capacitor, as viewed on the scope, however there was no sound output. I tried the safe way. It's time to break some rules. 
+
+I grabbed some 1uf (electrolytic polarized) caps I had, and tried these. Again, no sound. Not giving up, I grabbed some 1000uf 'lytics, and tried once more. Now it worked.
+
+\subsubsection{Impedance / ESR of capacitors failing to pass enough power of signal}
+Capacitors are rated for impedance. Some data sheets also call this ESR, it appears after a quick look. It's either in there as impedance or ESR. It's not initially an issue if you are using the capacitor as a DC reservoir, but if you use it in an AC coupling situation then things get interesting. A high impedance, or ESR will block what a low one won't. In this example, it's as simple as the Amplfier either being able to power a speaker or not. Higher capacity caps will have lower impedance. See the picture. Other brands put impedance in a graph, or just call it impedance. 
+
+\includegraphics[scale=0.5]{../pics/esr_impedance_capacitance.png}
+\captionof{figure}{Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.}
+
+\subsubsection{Wikipedia on Impedance}
+
+\emph{In general, a capacitor is seen as a storage component for electric energy. But this is only one capacitor function. A capacitor can also act as an AC resistor. Especially aluminum electrolytic capacitors are used in many applications as a decoupling capacitors to filter or bypass undesired biased AC frequencies to the ground or for capacitive coupling of audio AC signals. Then the dielectric is used only for blocking DC. For such applications the AC resistance, the impedance is as important as the capacitance value. }
+\begin{verbatim} https://en.wikipedia.org/w/index.php\title=Aluminum_electrolytic
+_capacitor&oldid=940281525
+\end{verbatim}
+Essentially, what I learned today.
+
+\section{DIY Amp}
+I was flipping through Practical Electronics for Inventors\cite{Scherz}(page 959), when I came across an audio amplifier. He also gives one at the chapter on Semiconductors (pg. 467), although the former is more detailed. With a reasonably simple schematic available, and a high likelihood of it working, I say why not: let's build it up.
+
+I've noticed that the ``Lvpin LP-838'' amplifier I'm using is underpowered for my two front speakers \footnote{Although it seems it would work for one channel, so two of them might be enough. It's rated for 20W, so that is about 15-20W per channel req'd. It works at 20W for both, just that it heats up too much. Multiple ebay sellers have it misquoted at 200W. Just an extra 0, no biggie. Based on all this, it appears each channel of my car speaker needs about 15 watts to be on the safe side. The example schematic is 16 watts. Two should suffice.}, so I will make two of the provided 16 watt amps.
+
+\subsection{LM383 is Obsolete}
+That explains why I haven't heard of it. The chip is obsolete. Some sell it on ebay for about \$5 each.
+
+As a different route, could I use some other power amplifier op amp, with the same pinout? Hm... Aha, the LM1875 has the same pinout. Let's use that.\footnote{How did I find this? I searched Digikey for the LM383 sold by rochester, noted it was it the category of Linear - Amplifiers - Audio, chose that, then searched for everything in the same package (TO220-5). Came right up. If this hadn't worked, I would've wanted to try other sites: Farnells, Mouser, etc...}
+
+Will it work with the same schematic? Questionable. May still need to buy a LM383, along with the LM1875, as backup. I might also try a generic power op amp.
+
+Amplfiers are the expensive bom item here.
+
+ 
+
+\section{References}
+\begin{thebibliography}{99}
+\bibitem{Scherz}
+  Paul Scherz, and Simon Monk,
+  \emph{Practical Electronics for Inventors}, fourth edition - 2016, McGraw Hill.
+
+  \end{thebibliography}
+
+\end{document}

Car_Stereo_Replacement/docs/17.aux

@@ -0,0 +1,24 @@
+\relax 
+\@writefile{toc}{\contentsline {section}{\numberline {1}Overview}{1}}
+\@writefile{lof}{\contentsline {figure}{\numberline {1}{\ignorespaces PCB rev 1\relax }}{1}}
+\@writefile{toc}{\contentsline {section}{\numberline {2}Items Included}{2}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {2.1}I2C OLED display}{2}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {2.2}Internal AVR Temperature Sensor}{3}}
+\@writefile{toc}{\contentsline {section}{\numberline {3}Wiring Pinout is wrong on Internet - Cable has labels}{3}}
+\@writefile{toc}{\contentsline {section}{\numberline {4}Arduino VReg Blowout}{3}}
+\@writefile{toc}{\contentsline {section}{\numberline {5}Amplifier}{3}}
+\@writefile{toc}{\contentsline {section}{\numberline {6}AC Audio Coupling to Remove DC Noise from Auto}{4}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {6.1}Ground Isolator}{4}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {6.2}Capacitor Audio Coupling}{4}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {6.2.1}Impedance / ESR of capacitors failing to pass enough power of signal}{5}}
+\@writefile{lof}{\contentsline {figure}{\numberline {2}{\ignorespaces Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.\relax }}{5}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {6.2.2}Wikipedia on Impedance}{5}}
+\citation{Scherz}
+\citation{eevblog}
+\@writefile{toc}{\contentsline {section}{\numberline {7}DIY Amp}{6}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {7.1}LM383 is Obsolete}{6}}
+\@writefile{toc}{\contentsline {section}{\numberline {8}Noise remains with Speaker Isolation}{6}}
+\bibcite{Scherz}{1}
+\bibcite{eevblog}{2}
+\bibcite{partofthe}{3}
+\@writefile{toc}{\contentsline {section}{\numberline {9}References}{7}}

Car_Stereo_Replacement/docs/17.log

@@ -0,0 +1,267 @@
+This is pdfTeX, Version 3.14159265-2.6-1.40.17 (TeX Live 2016/Debian) (preloaded format=pdflatex 2019.8.17)  26 FEB 2020 03:19
+entering extended mode
+ restricted \write18 enabled.
+ %&-line parsing enabled.
+**/home/layoutdev/Desktop/code/documentation_general/Electronics_Projects_2019/
+Car_Stereo_Replacement/docs/17.tex
+
+(/home/layoutdev/Desktop/code/documentation_general/Electronics_Projects_2019/C
+ar_Stereo_Replacement/docs/17.tex
+LaTeX2e <2017/01/01> patch level 3
+Babel <3.9r> and hyphenation patterns for 3 language(s) loaded.
+(/usr/share/texlive/texmf-dist/tex/latex/base/article.cls
+Document Class: article 2014/09/29 v1.4h Standard LaTeX document class
+(/usr/share/texlive/texmf-dist/tex/latex/base/size11.clo
+File: size11.clo 2014/09/29 v1.4h Standard LaTeX file (size option)
+)
+\c@part=\count79
+\c@section=\count80
+\c@subsection=\count81
+\c@subsubsection=\count82
+\c@paragraph=\count83
+\c@subparagraph=\count84
+\c@figure=\count85
+\c@table=\count86
+\abovecaptionskip=\skip41
+\belowcaptionskip=\skip42
+\bibindent=\dimen102
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/graphicx.sty
+Package: graphicx 2014/10/28 v1.0g Enhanced LaTeX Graphics (DPC,SPQR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/keyval.sty
+Package: keyval 2014/10/28 v1.15 key=value parser (DPC)
+\KV@toks@=\toks14
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/graphics.sty
+Package: graphics 2016/10/09 v1.0u Standard LaTeX Graphics (DPC,SPQR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/trig.sty
+Package: trig 2016/01/03 v1.10 sin cos tan (DPC)
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics-cfg/graphics.cfg
+File: graphics.cfg 2016/06/04 v1.11 sample graphics configuration
+)
+Package graphics Info: Driver file: pdftex.def on input line 99.
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics-def/pdftex.def
+File: pdftex.def 2017/01/12 v0.06k Graphics/color for pdfTeX
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/infwarerr.sty
+Package: infwarerr 2016/05/16 v1.4 Providing info/warning/error messages (HO)
+)
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ltxcmds.sty
+Package: ltxcmds 2016/05/16 v1.23 LaTeX kernel commands for general use (HO)
+)
+\Gread@gobject=\count87
+))
+\Gin@req@height=\dimen103
+\Gin@req@width=\dimen104
+)
+(/usr/share/texlive/texmf-dist/tex/latex/caption/caption.sty
+Package: caption 2016/02/21 v3.3-144 Customizing captions (AR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/caption/caption3.sty
+Package: caption3 2016/05/22 v1.7-166 caption3 kernel (AR)
+Package caption3 Info: TeX engine: e-TeX on input line 67.
+\captionmargin=\dimen105
+\captionmargin@=\dimen106
+\captionwidth=\dimen107
+\caption@tempdima=\dimen108
+\caption@indent=\dimen109
+\caption@parindent=\dimen110
+\caption@hangindent=\dimen111
+)
+\c@ContinuedFloat=\count88
+) (./17.aux)
+\openout1 = `17.aux'.
+
+LaTeX Font Info:    Checking defaults for OML/cmm/m/it on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for T1/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OT1/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OMS/cmsy/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OMX/cmex/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for U/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+
+(/usr/share/texlive/texmf-dist/tex/context/base/mkii/supp-pdf.mkii
+[Loading MPS to PDF converter (version 2006.09.02).]
+\scratchcounter=\count89
+\scratchdimen=\dimen112
+\scratchbox=\box26
+\nofMPsegments=\count90
+\nofMParguments=\count91
+\everyMPshowfont=\toks15
+\MPscratchCnt=\count92
+\MPscratchDim=\dimen113
+\MPnumerator=\count93
+\makeMPintoPDFobject=\count94
+\everyMPtoPDFconversion=\toks16
+) (/usr/share/texlive/texmf-dist/tex/generic/oberdiek/pdftexcmds.sty
+Package: pdftexcmds 2016/05/21 v0.22 Utility functions of pdfTeX for LuaTeX (HO
+)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ifluatex.sty
+Package: ifluatex 2016/05/16 v1.4 Provides the ifluatex switch (HO)
+Package ifluatex Info: LuaTeX not detected.
+)
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ifpdf.sty
+Package: ifpdf 2016/05/14 v3.1 Provides the ifpdf switch
+)
+Package pdftexcmds Info: LuaTeX not detected.
+Package pdftexcmds Info: \pdf@primitive is available.
+Package pdftexcmds Info: \pdf@ifprimitive is available.
+Package pdftexcmds Info: \pdfdraftmode found.
+)
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/epstopdf-base.sty
+Package: epstopdf-base 2016/05/15 v2.6 Base part for package epstopdf
+
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/grfext.sty
+Package: grfext 2016/05/16 v1.2 Manage graphics extensions (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/kvdefinekeys.sty
+Package: kvdefinekeys 2016/05/16 v1.4 Define keys (HO)
+))
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/kvoptions.sty
+Package: kvoptions 2016/05/16 v3.12 Key value format for package options (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/kvsetkeys.sty
+Package: kvsetkeys 2016/05/16 v1.17 Key value parser (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/etexcmds.sty
+Package: etexcmds 2016/05/16 v1.6 Avoid name clashes with e-TeX commands (HO)
+Package etexcmds Info: Could not find \expanded.
+(etexcmds)             That can mean that you are not using pdfTeX 1.50 or
+(etexcmds)             that some package has redefined \expanded.
+(etexcmds)             In the latter case, load this package earlier.
+)))
+Package epstopdf-base Info: Redefining graphics rule for `.eps' on input line 4
+38.
+Package grfext Info: Graphics extension search list:
+(grfext)             [.png,.pdf,.jpg,.mps,.jpeg,.jbig2,.jb2,.PNG,.PDF,.JPG,.JPE
+G,.JBIG2,.JB2,.eps]
+(grfext)             \AppendGraphicsExtensions on input line 456.
+
+(/usr/share/texlive/texmf-dist/tex/latex/latexconfig/epstopdf-sys.cfg
+File: epstopdf-sys.cfg 2010/07/13 v1.3 Configuration of (r)epstopdf for TeX Liv
+e
+))
+Package caption Info: Begin \AtBeginDocument code.
+Package caption Info: End \AtBeginDocument code.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <12> on input line 9.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <8> on input line 9.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <6> on input line 9.
+
+
+LaTeX Warning: No \author given.
+
+
+Underfull \hbox (badness 10000) in paragraph at lines 12--14
+
+ []
+
+<../pics/DSCN2180.JPG, id=1, 803.0pt x 602.25pt>
+File: ../pics/DSCN2180.JPG Graphic file (type jpg)
+ <use ../pics/DSCN2180.JPG>
+Package pdftex.def Info: ../pics/DSCN2180.JPG used on input line 15.
+(pdftex.def)             Requested size: 321.1943pt x 240.89572pt.
+
+
+Package caption Warning: \captionsetup{type*=...} or \captionof
+(caption)                outside box or environment on input line 16.
+See the caption package documentation for explanation.
+
+[1
+
+{/var/lib/texmf/fonts/map/pdftex/updmap/pdftex.map} <../pics/DSCN2180.JPG>]
+LaTeX Font Info:    Try loading font information for OMS+cmr on input line 21.
+
+(/usr/share/texlive/texmf-dist/tex/latex/base/omscmr.fd
+File: omscmr.fd 2014/09/29 v2.5h Standard LaTeX font definitions
+)
+LaTeX Font Info:    Font shape `OMS/cmr/m/n' in size <10.95> not available
+(Font)              Font shape `OMS/cmsy/m/n' tried instead on input line 21.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <10.95> on input line 30.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <9> on input line 30.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <5> on input line 30.
+
+Underfull \hbox (badness 10000) in paragraph at lines 46--47
+[]\OT1/cmr/m/n/10.95 https://thecavepearlproject.org/2019/02/25/no-parts-temper
+ature-
+ []
+
+[2] [3] [4]
+<../pics/esr_impedance_capacitance.png, id=24, 697.10437pt x 421.69917pt>
+File: ../pics/esr_impedance_capacitance.png Graphic file (type png)
+
+<use ../pics/esr_impedance_capacitance.png>
+Package pdftex.def Info: ../pics/esr_impedance_capacitance.png used on input li
+ne 75.
+(pdftex.def)             Requested size: 348.55133pt x 210.84906pt.
+
+Overfull \hbox (13.6647pt too wide) in paragraph at lines 83--83
+[] \OT1/cmtt/m/n/10.95 https://en.wikipedia.org/w/index.php\title=Aluminum_elec
+trolytic 
+ []
+
+[5 <../pics/esr_impedance_capacitance.png (PNG copy)>] [6]
+Underfull \hbox (badness 10000) in paragraph at lines 113--114
+[]\OT1/cmr/m/n/10.95 Various, \OT1/cmr/m/it/10.95 https://www.eevblog.com/forum
+/projects/dreaded-
+ []
+
+
+Underfull \hbox (badness 10000) in paragraph at lines 113--114
+\OT1/cmr/m/it/10.95 alternator-whine-in-car-stereo/25/ \OT1/cmr/m/n/10.95 Re-tr
+ieved 2020-02-21. see
+ []
+
+
+Underfull \hbox (badness 10000) in paragraph at lines 113--114
+\OT1/cmr/m/n/10.95 also https://www.eevblog.com/forum/beginners/car-engine-sign
+al-
+ []
+
+
+Underfull \hbox (badness 10000) in paragraph at lines 116--117
+[]\OT1/cmr/m/it/10.95 https://partofthething.com/thoughts/building-a-low-pass-f
+ilter-to-
+ []
+
+[7] (./17.aux) ) 
+Here is how much of TeX's memory you used:
+ 2611 strings out of 494945
+ 41795 string characters out of 6181032
+ 96839 words of memory out of 5000000
+ 5897 multiletter control sequences out of 15000+600000
+ 10544 words of font info for 37 fonts, out of 8000000 for 9000
+ 14 hyphenation exceptions out of 8191
+ 39i,8n,39p,867b,229s stack positions out of 5000i,500n,10000p,200000b,80000s
+</usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/c
+mbx10.pfb></usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmbx12.
+pfb></usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmr10.pfb></u
+sr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmr12.pfb></usr/shar
+e/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmr6.pfb></usr/share/texliv
+e/texmf-dist/fonts/type1/public/amsfonts/cm/cmr8.pfb></usr/share/texlive/texmf-
+dist/fonts/type1/public/amsfonts/cm/cmr9.pfb></usr/share/texlive/texmf-dist/fon
+ts/type1/public/amsfonts/cm/cmsy10.pfb></usr/share/texlive/texmf-dist/fonts/typ
+e1/public/amsfonts/cm/cmti10.pfb></usr/share/texlive/texmf-dist/fonts/type1/pub
+lic/amsfonts/cm/cmtt10.pfb>
+Output written on 17.pdf (7 pages, 391358 bytes).
+PDF statistics:
+ 70 PDF objects out of 1000 (max. 8388607)
+ 48 compressed objects within 1 object stream
+ 0 named destinations out of 1000 (max. 500000)
+ 11 words of extra memory for PDF output out of 10000 (max. 10000000)
+

Car_Stereo_Replacement/docs/17.tex

@@ -0,0 +1,119 @@
+\documentclass[11pt]{article}
+%Gummi|065|=)
+\title{\textbf{Car Stereo Replacement}}
+\usepackage{graphicx,caption}
+%\author{Steak Electronics}
+\date{02/13/20}
+\begin{document}
+
+\maketitle
+
+\section{Overview}
+Replacing a car stereo. I could just go to ebay, and buy a used car stereo, but where's the fun in that? Let's DIY a car stereo from a PCB used as a frontplate, a connector for my vehicle, and an audio amplifier. I'll connect in signal from an audio player.
+\\
+
+\includegraphics[scale=0.4]{../pics/DSCN2180.JPG}
+\captionof{figure}{PCB rev 1}
+
+\section{Items Included}
+I thought I would include the following:
+\begin{itemize}
+\item Arduino Nano
+\item Voltage and Gnd Breakout
+\item I2C Display
+\item Voltage Readout (of BAT)
+\item Current Readout (being drawn)
+\item Amplifier ``Lvpin LP-838''
+\end{itemize}
+I also wanted to have the connectors that eurorack and synth designers use for mono audio cables, but the cables turned out too expensive. The current readout didn't work initially, and I haven't gotten to fixing it yet.
+\subsection{I2C OLED display}
+Just for fun, I bought an I2C oled display and am going to use it to display something.\footnote{It's an Arduino Uno, you can put almost anything on this.} Notes on this:
+Using the adafruit SSD1306 and GFX library (this procedure is well covered in other places), you can load an example sketch and get it running. First thing to change is to remove the Adafruit logo and replace it with my own. Let's do that.
+
+From https://design.goeszen.com/convert-image-for-oled-display.html
+\begin{verbatim}
+I'm on Linux here and found that the readily-available 
+ImageMagick package will do the trick for you without
+ any scripting. And runs on the CLI! Simple as that:
+
+    convert some_image.png some.image.mono
+\end{verbatim}
+That's efficient. But it didn't really work out. Too much work, I don't need it that bad. Have to convert it to something the c compiler can read. I instead, just deleted their logo. Good enough for now.
+\subsection{Internal AVR Temperature Sensor}
+
+I setup the code to read from the internal temp sensor on the duino. However there is also this:
+
+https://thecavepearlproject.org/2019/02/25/no-parts-temperature-measurement-with-arduino-pro-mini-to-0-005c-or-better/
+
+This would be something to do for more resolution. The built in sensor is not very good, so this above link would be great. Hack a day also covers it. 
+
+\section{Wiring Pinout is wrong on Internet - Cable has labels}
+I looked at the picture I have detailing the pinout of my car connector (Delco Delphi radio wiring diagram.jpg in resources). It's close, but not 100\% correct. I found that the cable itself has small text labels on each wire which explain which everything does. I didn't notice earlier, as I didn't look close enough (and no one mentioned this).
+
+\section{Arduino VReg Blowout}
+I had a knock off Arduino Nano, and the vreg blew out. I have some other vregs to replace it. I didn't have this problem with an Uno that I use as a ceiling dome light. Although that one is not left on as long, usually. 
+
+\section{Amplifier}
+The amplifier I used is one of the cheapest avialable on ebay. I'm not proud. I'm poor. I had to take it apart, and reseat the amplifier ICs as the tab was not making contact with the chassis for one of them. I also added thermal paste. This amp is underpowered for my car, and may need replacing. It gets a bit hot.
+
+Some other issues with this amplifier are that the output connectors can get pushed back, there is only one output connector option, and it must run on battery power, as a 12V 1A or 2A will not power it. Finally, there is a 6V DC bias on output. No output audio isolation, which means you get car noise.
+
+\section{AC Audio Coupling to Remove DC Noise from Auto}
+I had some fun with this one. Many videos on this in the video folder. I started with the speakers being directly fed by the amplifier. This worked, but there was some noise coming through. Cars are noisy, this is not surprising. I would've preferred the amplifier to isolate the outputs, but no luck... At this point, I considered two options to block DC and allow AC. 1) Use a transformer. 2) Use capacitors.\footnote{A third option would've been to use a second set of batteries, but that would be laborious.}
+
+\subsection{Ground Isolator}
+I had been given a Ground isolator, which was two small transformers on a pcb intended to pass audio from a car powered signal source into the car speakers. I tried this isolator on the output of the speakers, and while it worked, the volume was lower, and it was impractical. I knew as soon as I heard the volume, that the issue was an impedance matching problem. The transformers were too small. They were intended for signal sources, not amplifier outputs. Onto option \#2.
+
+\subsection{Capacitor Audio Coupling}
+My initial thoughts here were: ``Let's be careful and use non polarized caps''. I bought some 0.22uf and 0.022uf polyester film capacitors at Electronics Plus, the local radioshack replacement, and tried them. No sound. After adjusting the connectors on the amp (which were admittedly loose - it's easy to push them back on the amplifier if you are not careful) I found that the capacitors didn't work. One problem was evident in the oscope. I only used one capacitor on the + output of the speaker amp, but the Amp biases the signal 6 volts. So I needed two. After that was resolved, the signal came through on the output of the capacitor, as viewed on the scope, however there was no sound output. I tried the safe way. It's time to break some rules. 
+
+I grabbed some 1uf (electrolytic polarized) caps I had, and tried these. Again, no sound. Not giving up, I grabbed some 1000uf 'lytics, and tried once more. Now it worked.
+
+\subsubsection{Impedance / ESR of capacitors failing to pass enough power of signal}
+Capacitors are rated for impedance. Some data sheets also call this ESR, it appears after a quick look. It's either in there as impedance or ESR. It's not initially an issue if you are using the capacitor as a DC reservoir, but if you use it in an AC coupling situation then things get interesting. A high impedance, or ESR will block what a low one won't. In this example, it's as simple as the Amplfier either being able to power a speaker or not. Higher capacity caps will have lower impedance. See the picture. Other brands put impedance in a graph, or just call it impedance. 
+
+\includegraphics[scale=0.5]{../pics/esr_impedance_capacitance.png}
+\captionof{figure}{Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.}
+
+\subsubsection{Wikipedia on Impedance}
+
+\emph{In general, a capacitor is seen as a storage component for electric energy. But this is only one capacitor function. A capacitor can also act as an AC resistor. Especially aluminum electrolytic capacitors are used in many applications as a decoupling capacitors to filter or bypass undesired biased AC frequencies to the ground or for capacitive coupling of audio AC signals. Then the dielectric is used only for blocking DC. For such applications the AC resistance, the impedance is as important as the capacitance value. }
+\begin{verbatim} https://en.wikipedia.org/w/index.php\title=Aluminum_electrolytic
+_capacitor&oldid=940281525
+\end{verbatim}
+Essentially, what I learned today.
+
+\section{DIY Amp}
+I was flipping through Practical Electronics for Inventors\cite{Scherz}(page 959), when I came across an audio amplifier. He also gives one at the chapter on Semiconductors (pg. 467), although the former is more detailed. With a reasonably simple schematic available, and a high likelihood of it working, I say why not: let's build it up.
+
+I've noticed that the ``Lvpin LP-838'' amplifier I'm using is underpowered for my two front speakers \footnote{Although it seems it would work for one channel, so two of them might be enough. It's rated for 20W, so that is about 15-20W per channel req'd. It works at 20W for both, just that it heats up too much. Multiple ebay sellers have it misquoted at 200W. Just an extra 0, no biggie. Based on all this, it appears each channel of my car speaker needs about 15 watts to be on the safe side. The example schematic is 16 watts. Two should suffice.}, so I will make two of the provided 16 watt amps.
+
+\subsection{LM383 is Obsolete}
+That explains why I haven't heard of it. The chip is obsolete. Some sell it on ebay for about \$5 each.
+
+As a different route, could I use some other power amplifier op amp, with the same pinout? Hm... Aha, the LM1875 has the same pinout. Let's use that.\footnote{How did I find this? I searched Digikey for the LM383 sold by rochester, noted it was it the category of Linear - Amplifiers - Audio, chose that, then searched for everything in the same package (TO220-5). Came right up. If this hadn't worked, I would've wanted to try other sites: Farnells, Mouser, etc...}
+
+Will it work with the same schematic? Questionable. May still need to buy a LM383, along with the LM1875, as backup. I might also try a generic power op amp.
+
+Amplfiers are the expensive bom item here.
+
+\section{Noise remains with Speaker Isolation}
+I've isolated the speakers from DC with the caps, but noise remains. My next idea was a DC-DC isolated supply. But, I found two threads on eevblog forums\cite{eevblog}, and they recommend a power line filter (they also mention the isolated supply). A filter with a coil and cap (2200uf even low enough) I can quickly build up.
+
+I also want to fix up my portable CRO, I obtained the other day. That needs batteries.
+ 
+
+\section{References}
+\begin{thebibliography}{99}
+\bibitem{Scherz}
+  Paul Scherz, and Simon Monk,
+  \emph{Practical Electronics for Inventors}, fourth edition - 2016, McGraw Hill.
+
+\bibitem{eevblog}
+  Various, \emph{https://www.eevblog.com/forum/projects/dreaded-alternator-whine-in-car-stereo/25/} Retrieved 2020-02-21. see also https://www.eevblog.com/forum/beginners/car-engine-signal-interference-with-cell-phone/
+
+\bibitem{partofthe}
+  \emph{https://partofthething.com/thoughts/building-a-low-pass-filter-to-remove-alternator-whine-in-my-car/}. Picture guide and showing basic build in project box. Eevblog users mention you may be able to use the secondary of a transformer, to avoid building the coil.
+  \end{thebibliography}
+
+\end{document}

Car_Stereo_Replacement/docs/17.tex~

@@ -0,0 +1,117 @@
+\documentclass[11pt]{article}
+%Gummi|065|=)
+\title{\textbf{Car Stereo Replacement}}
+\usepackage{graphicx,caption}
+%\author{Steak Electronics}
+\date{02/13/20}
+\begin{document}
+
+\maketitle
+
+\section{Overview}
+Replacing a car stereo. I could just go to ebay, and buy a used car stereo, but where's the fun in that? Let's DIY a car stereo from a PCB used as a frontplate, a connector for my vehicle, and an audio amplifier. I'll connect in signal from an audio player.
+\\
+
+\includegraphics[scale=0.4]{../pics/DSCN2180.JPG}
+\captionof{figure}{PCB rev 1}
+
+\section{Items Included}
+I thought I would include the following:
+\begin{itemize}
+\item Arduino Nano
+\item Voltage and Gnd Breakout
+\item I2C Display
+\item Voltage Readout (of BAT)
+\item Current Readout (being drawn)
+\item Amplifier ``Lvpin LP-838''
+\end{itemize}
+I also wanted to have the connectors that eurorack and synth designers use for mono audio cables, but the cables turned out too expensive. The current readout didn't work initially, and I haven't gotten to fixing it yet.
+\subsection{I2C OLED display}
+Just for fun, I bought an I2C oled display and am going to use it to display something.\footnote{It's an Arduino Uno, you can put almost anything on this.} Notes on this:
+Using the adafruit SSD1306 and GFX library (this procedure is well covered in other places), you can load an example sketch and get it running. First thing to change is to remove the Adafruit logo and replace it with my own. Let's do that.
+
+From https://design.goeszen.com/convert-image-for-oled-display.html
+\begin{verbatim}
+I'm on Linux here and found that the readily-available 
+ImageMagick package will do the trick for you without
+ any scripting. And runs on the CLI! Simple as that:
+
+    convert some_image.png some.image.mono
+\end{verbatim}
+That's efficient. But it didn't really work out. Too much work, I don't need it that bad. Have to convert it to something the c compiler can read. I instead, just deleted their logo. Good enough for now.
+\subsection{Internal AVR Temperature Sensor}
+
+I setup the code to read from the internal temp sensor on the duino. However there is also this:
+
+https://thecavepearlproject.org/2019/02/25/no-parts-temperature-measurement-with-arduino-pro-mini-to-0-005c-or-better/
+
+This would be something to do for more resolution. The built in sensor is not very good, so this above link would be great. Hack a day also covers it. 
+
+\section{Wiring Pinout is wrong on Internet - Cable has labels}
+I looked at the picture I have detailing the pinout of my car connector (Delco Delphi radio wiring diagram.jpg in resources). It's close, but not 100\% correct. I found that the cable itself has small text labels on each wire which explain which everything does. I didn't notice earlier, as I didn't look close enough (and no one mentioned this).
+
+\section{Arduino VReg Blowout}
+I had a knock off Arduino Nano, and the vreg blew out. I have some other vregs to replace it. I didn't have this problem with an Uno that I use as a ceiling dome light. Although that one is not left on as long, usually. 
+
+\section{Amplifier}
+The amplifier I used is one of the cheapest avialable on ebay. I'm not proud. I'm poor. I had to take it apart, and reseat the amplifier ICs as the tab was not making contact with the chassis for one of them. I also added thermal paste. This amp is underpowered for my car, and may need replacing. It gets a bit hot.
+
+Some other issues with this amplifier are that the output connectors can get pushed back, there is only one output connector option, and it must run on battery power, as a 12V 1A or 2A will not power it. Finally, there is a 6V DC bias on output. No output audio isolation, which means you get car noise.
+
+\section{AC Audio Coupling to Remove DC Noise from Auto}
+I had some fun with this one. Many videos on this in the video folder. I started with the speakers being directly fed by the amplifier. This worked, but there was some noise coming through. Cars are noisy, this is not surprising. I would've preferred the amplifier to isolate the outputs, but no luck... At this point, I considered two options to block DC and allow AC. 1) Use a transformer. 2) Use capacitors.\footnote{A third option would've been to use a second set of batteries, but that would be laborious.}
+
+\subsection{Ground Isolator}
+I had been given a Ground isolator, which was two small transformers on a pcb intended to pass audio from a car powered signal source into the car speakers. I tried this isolator on the output of the speakers, and while it worked, the volume was lower, and it was impractical. I knew as soon as I heard the volume, that the issue was an impedance matching problem. The transformers were too small. They were intended for signal sources, not amplifier outputs. Onto option \#2.
+
+\subsection{Capacitor Audio Coupling}
+My initial thoughts here were: ``Let's be careful and use non polarized caps''. I bought some 0.22uf and 0.022uf polyester film capacitors at Electronics Plus, the local radioshack replacement, and tried them. No sound. After adjusting the connectors on the amp (which were admittedly loose - it's easy to push them back on the amplifier if you are not careful) I found that the capacitors didn't work. One problem was evident in the oscope. I only used one capacitor on the + output of the speaker amp, but the Amp biases the signal 6 volts. So I needed two. After that was resolved, the signal came through on the output of the capacitor, as viewed on the scope, however there was no sound output. I tried the safe way. It's time to break some rules. 
+
+I grabbed some 1uf (electrolytic polarized) caps I had, and tried these. Again, no sound. Not giving up, I grabbed some 1000uf 'lytics, and tried once more. Now it worked.
+
+\subsubsection{Impedance / ESR of capacitors failing to pass enough power of signal}
+Capacitors are rated for impedance. Some data sheets also call this ESR, it appears after a quick look. It's either in there as impedance or ESR. It's not initially an issue if you are using the capacitor as a DC reservoir, but if you use it in an AC coupling situation then things get interesting. A high impedance, or ESR will block what a low one won't. In this example, it's as simple as the Amplfier either being able to power a speaker or not. Higher capacity caps will have lower impedance. See the picture. Other brands put impedance in a graph, or just call it impedance. 
+
+\includegraphics[scale=0.5]{../pics/esr_impedance_capacitance.png}
+\captionof{figure}{Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.}
+
+\subsubsection{Wikipedia on Impedance}
+
+\emph{In general, a capacitor is seen as a storage component for electric energy. But this is only one capacitor function. A capacitor can also act as an AC resistor. Especially aluminum electrolytic capacitors are used in many applications as a decoupling capacitors to filter or bypass undesired biased AC frequencies to the ground or for capacitive coupling of audio AC signals. Then the dielectric is used only for blocking DC. For such applications the AC resistance, the impedance is as important as the capacitance value. }
+\begin{verbatim} https://en.wikipedia.org/w/index.php\title=Aluminum_electrolytic
+_capacitor&oldid=940281525
+\end{verbatim}
+Essentially, what I learned today.
+
+\section{DIY Amp}
+I was flipping through Practical Electronics for Inventors\cite{Scherz}(page 959), when I came across an audio amplifier. He also gives one at the chapter on Semiconductors (pg. 467), although the former is more detailed. With a reasonably simple schematic available, and a high likelihood of it working, I say why not: let's build it up.
+
+I've noticed that the ``Lvpin LP-838'' amplifier I'm using is underpowered for my two front speakers \footnote{Although it seems it would work for one channel, so two of them might be enough. It's rated for 20W, so that is about 15-20W per channel req'd. It works at 20W for both, just that it heats up too much. Multiple ebay sellers have it misquoted at 200W. Just an extra 0, no biggie. Based on all this, it appears each channel of my car speaker needs about 15 watts to be on the safe side. The example schematic is 16 watts. Two should suffice.}, so I will make two of the provided 16 watt amps.
+
+\subsection{LM383 is Obsolete}
+That explains why I haven't heard of it. The chip is obsolete. Some sell it on ebay for about \$5 each.
+
+As a different route, could I use some other power amplifier op amp, with the same pinout? Hm... Aha, the LM1875 has the same pinout. Let's use that.\footnote{How did I find this? I searched Digikey for the LM383 sold by rochester, noted it was it the category of Linear - Amplifiers - Audio, chose that, then searched for everything in the same package (TO220-5). Came right up. If this hadn't worked, I would've wanted to try other sites: Farnells, Mouser, etc...}
+
+Will it work with the same schematic? Questionable. May still need to buy a LM383, along with the LM1875, as backup. I might also try a generic power op amp.
+
+Amplfiers are the expensive bom item here.
+
+\section{Noise remains with Speaker Isolation}
+I've isolated the speakers from DC with the caps, but noise remains. My next idea was a DC-DC isolated supply. But, I found two threads on eevblog forums\cite{eevblogforums}, and they recommend a power line filter (they also mention the isolated supply). A filter with a coil and cap (2200uf even low enough) I can quickly build up. 
+ 
+
+\section{References}
+\begin{thebibliography}{99}
+\bibitem{Scherz}
+  Paul Scherz, and Simon Monk,
+  \emph{Practical Electronics for Inventors}, fourth edition - 2016, McGraw Hill.
+
+\bibitem{eevblogforums}
+  Various, \emph{https://www.eevblog.com/forum/projects/dreaded-alternator-whine-in-car-stereo/25/} Retrieved 2020-02-21.
+
+  see also https://www.eevblog.com/forum/beginners/car-engine-signal-interference-with-cell-phone/
+  
+  \end{thebibliography}
+
+\end{document}

Car_Stereo_Replacement/docs/18.aux

@@ -0,0 +1,25 @@
+\relax 
+\@writefile{toc}{\contentsline {section}{\numberline {1}Overview}{1}}
+\@writefile{lof}{\contentsline {figure}{\numberline {1}{\ignorespaces PCB rev 1\relax }}{1}}
+\@writefile{toc}{\contentsline {section}{\numberline {2}Items Included}{2}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {2.1}I2C OLED display}{2}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {2.2}Internal AVR Temperature Sensor}{3}}
+\@writefile{toc}{\contentsline {section}{\numberline {3}Wiring Pinout is wrong on Internet - Cable has labels}{3}}
+\@writefile{toc}{\contentsline {section}{\numberline {4}Arduino VReg Blowout}{3}}
+\@writefile{toc}{\contentsline {section}{\numberline {5}Amplifier}{3}}
+\@writefile{toc}{\contentsline {section}{\numberline {6}AC Audio Coupling to Remove DC Noise from Auto}{4}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {6.1}Ground Isolator}{4}}
+\@writefile{lof}{\contentsline {figure}{\numberline {2}{\ignorespaces Ground Loop Isolator.\relax }}{4}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {6.2}Capacitor Audio Coupling}{5}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {6.2.1}Impedance / ESR of capacitors failing to pass enough power of signal}{5}}
+\citation{Scherz}
+\@writefile{lof}{\contentsline {figure}{\numberline {3}{\ignorespaces Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.\relax }}{6}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {6.2.2}Wikipedia on Impedance}{6}}
+\@writefile{toc}{\contentsline {section}{\numberline {7}DIY Amp}{6}}
+\citation{eevblog}
+\bibcite{Scherz}{1}
+\@writefile{toc}{\contentsline {subsection}{\numberline {7.1}LM383 is Obsolete}{7}}
+\@writefile{toc}{\contentsline {section}{\numberline {8}Noise remains with Speaker Isolation}{7}}
+\bibcite{eevblog}{2}
+\bibcite{partofthe}{3}
+\@writefile{toc}{\contentsline {section}{\numberline {9}References}{8}}

Car_Stereo_Replacement/docs/18.log

@@ -0,0 +1,278 @@
+This is pdfTeX, Version 3.14159265-2.6-1.40.17 (TeX Live 2016/Debian) (preloaded format=pdflatex 2019.8.17)  26 FEB 2020 03:21
+entering extended mode
+ restricted \write18 enabled.
+ %&-line parsing enabled.
+**/home/layoutdev/Desktop/code/documentation_general/Electronics_Projects_2019/
+Car_Stereo_Replacement/docs/18.tex
+
+(/home/layoutdev/Desktop/code/documentation_general/Electronics_Projects_2019/C
+ar_Stereo_Replacement/docs/18.tex
+LaTeX2e <2017/01/01> patch level 3
+Babel <3.9r> and hyphenation patterns for 3 language(s) loaded.
+(/usr/share/texlive/texmf-dist/tex/latex/base/article.cls
+Document Class: article 2014/09/29 v1.4h Standard LaTeX document class
+(/usr/share/texlive/texmf-dist/tex/latex/base/size11.clo
+File: size11.clo 2014/09/29 v1.4h Standard LaTeX file (size option)
+)
+\c@part=\count79
+\c@section=\count80
+\c@subsection=\count81
+\c@subsubsection=\count82
+\c@paragraph=\count83
+\c@subparagraph=\count84
+\c@figure=\count85
+\c@table=\count86
+\abovecaptionskip=\skip41
+\belowcaptionskip=\skip42
+\bibindent=\dimen102
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/graphicx.sty
+Package: graphicx 2014/10/28 v1.0g Enhanced LaTeX Graphics (DPC,SPQR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/keyval.sty
+Package: keyval 2014/10/28 v1.15 key=value parser (DPC)
+\KV@toks@=\toks14
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/graphics.sty
+Package: graphics 2016/10/09 v1.0u Standard LaTeX Graphics (DPC,SPQR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/trig.sty
+Package: trig 2016/01/03 v1.10 sin cos tan (DPC)
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics-cfg/graphics.cfg
+File: graphics.cfg 2016/06/04 v1.11 sample graphics configuration
+)
+Package graphics Info: Driver file: pdftex.def on input line 99.
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics-def/pdftex.def
+File: pdftex.def 2017/01/12 v0.06k Graphics/color for pdfTeX
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/infwarerr.sty
+Package: infwarerr 2016/05/16 v1.4 Providing info/warning/error messages (HO)
+)
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ltxcmds.sty
+Package: ltxcmds 2016/05/16 v1.23 LaTeX kernel commands for general use (HO)
+)
+\Gread@gobject=\count87
+))
+\Gin@req@height=\dimen103
+\Gin@req@width=\dimen104
+)
+(/usr/share/texlive/texmf-dist/tex/latex/caption/caption.sty
+Package: caption 2016/02/21 v3.3-144 Customizing captions (AR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/caption/caption3.sty
+Package: caption3 2016/05/22 v1.7-166 caption3 kernel (AR)
+Package caption3 Info: TeX engine: e-TeX on input line 67.
+\captionmargin=\dimen105
+\captionmargin@=\dimen106
+\captionwidth=\dimen107
+\caption@tempdima=\dimen108
+\caption@indent=\dimen109
+\caption@parindent=\dimen110
+\caption@hangindent=\dimen111
+)
+\c@ContinuedFloat=\count88
+) (./18.aux)
+\openout1 = `18.aux'.
+
+LaTeX Font Info:    Checking defaults for OML/cmm/m/it on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for T1/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OT1/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OMS/cmsy/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OMX/cmex/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for U/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+
+(/usr/share/texlive/texmf-dist/tex/context/base/mkii/supp-pdf.mkii
+[Loading MPS to PDF converter (version 2006.09.02).]
+\scratchcounter=\count89
+\scratchdimen=\dimen112
+\scratchbox=\box26
+\nofMPsegments=\count90
+\nofMParguments=\count91
+\everyMPshowfont=\toks15
+\MPscratchCnt=\count92
+\MPscratchDim=\dimen113
+\MPnumerator=\count93
+\makeMPintoPDFobject=\count94
+\everyMPtoPDFconversion=\toks16
+) (/usr/share/texlive/texmf-dist/tex/generic/oberdiek/pdftexcmds.sty
+Package: pdftexcmds 2016/05/21 v0.22 Utility functions of pdfTeX for LuaTeX (HO
+)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ifluatex.sty
+Package: ifluatex 2016/05/16 v1.4 Provides the ifluatex switch (HO)
+Package ifluatex Info: LuaTeX not detected.
+)
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ifpdf.sty
+Package: ifpdf 2016/05/14 v3.1 Provides the ifpdf switch
+)
+Package pdftexcmds Info: LuaTeX not detected.
+Package pdftexcmds Info: \pdf@primitive is available.
+Package pdftexcmds Info: \pdf@ifprimitive is available.
+Package pdftexcmds Info: \pdfdraftmode found.
+)
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/epstopdf-base.sty
+Package: epstopdf-base 2016/05/15 v2.6 Base part for package epstopdf
+
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/grfext.sty
+Package: grfext 2016/05/16 v1.2 Manage graphics extensions (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/kvdefinekeys.sty
+Package: kvdefinekeys 2016/05/16 v1.4 Define keys (HO)
+))
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/kvoptions.sty
+Package: kvoptions 2016/05/16 v3.12 Key value format for package options (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/kvsetkeys.sty
+Package: kvsetkeys 2016/05/16 v1.17 Key value parser (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/etexcmds.sty
+Package: etexcmds 2016/05/16 v1.6 Avoid name clashes with e-TeX commands (HO)
+Package etexcmds Info: Could not find \expanded.
+(etexcmds)             That can mean that you are not using pdfTeX 1.50 or
+(etexcmds)             that some package has redefined \expanded.
+(etexcmds)             In the latter case, load this package earlier.
+)))
+Package epstopdf-base Info: Redefining graphics rule for `.eps' on input line 4
+38.
+Package grfext Info: Graphics extension search list:
+(grfext)             [.png,.pdf,.jpg,.mps,.jpeg,.jbig2,.jb2,.PNG,.PDF,.JPG,.JPE
+G,.JBIG2,.JB2,.eps]
+(grfext)             \AppendGraphicsExtensions on input line 456.
+
+(/usr/share/texlive/texmf-dist/tex/latex/latexconfig/epstopdf-sys.cfg
+File: epstopdf-sys.cfg 2010/07/13 v1.3 Configuration of (r)epstopdf for TeX Liv
+e
+))
+Package caption Info: Begin \AtBeginDocument code.
+Package caption Info: End \AtBeginDocument code.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <12> on input line 9.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <8> on input line 9.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <6> on input line 9.
+
+
+LaTeX Warning: No \author given.
+
+
+Underfull \hbox (badness 10000) in paragraph at lines 12--14
+
+ []
+
+<../pics/DSCN2180.JPG, id=1, 803.0pt x 602.25pt>
+File: ../pics/DSCN2180.JPG Graphic file (type jpg)
+ <use ../pics/DSCN2180.JPG>
+Package pdftex.def Info: ../pics/DSCN2180.JPG used on input line 15.
+(pdftex.def)             Requested size: 321.1943pt x 240.89572pt.
+
+
+Package caption Warning: \captionsetup{type*=...} or \captionof
+(caption)                outside box or environment on input line 16.
+See the caption package documentation for explanation.
+
+[1
+
+{/var/lib/texmf/fonts/map/pdftex/updmap/pdftex.map} <../pics/DSCN2180.JPG>]
+LaTeX Font Info:    Try loading font information for OMS+cmr on input line 21.
+
+(/usr/share/texlive/texmf-dist/tex/latex/base/omscmr.fd
+File: omscmr.fd 2014/09/29 v2.5h Standard LaTeX font definitions
+)
+LaTeX Font Info:    Font shape `OMS/cmr/m/n' in size <10.95> not available
+(Font)              Font shape `OMS/cmsy/m/n' tried instead on input line 21.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <10.95> on input line 30.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <9> on input line 30.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <5> on input line 30.
+
+Underfull \hbox (badness 10000) in paragraph at lines 46--47
+[]\OT1/cmr/m/n/10.95 https://thecavepearlproject.org/2019/02/25/no-parts-temper
+ature-
+ []
+
+[2] [3]
+Underfull \hbox (badness 10000) in paragraph at lines 65--67
+
+ []
+
+<../pics/DSCN2610.JPG, id=21, 803.0pt x 602.25pt>
+File: ../pics/DSCN2610.JPG Graphic file (type jpg)
+ <use ../pics/DSCN2610.JPG>
+Package pdftex.def Info: ../pics/DSCN2610.JPG used on input line 69.
+(pdftex.def)             Requested size: 281.05421pt x 210.79065pt.
+
+[4 <../pics/DSCN2610.JPG>]
+<../pics/esr_impedance_capacitance.png, id=25, 697.10437pt x 421.69917pt>
+File: ../pics/esr_impedance_capacitance.png Graphic file (type png)
+
+<use ../pics/esr_impedance_capacitance.png>
+Package pdftex.def Info: ../pics/esr_impedance_capacitance.png used on input li
+ne 80.
+(pdftex.def)             Requested size: 348.55133pt x 210.84906pt.
+ [5]
+Overfull \hbox (13.6647pt too wide) in paragraph at lines 88--88
+[] \OT1/cmtt/m/n/10.95 https://en.wikipedia.org/w/index.php\title=Aluminum_elec
+trolytic 
+ []
+
+[6 <../pics/esr_impedance_capacitance.png (PNG copy)>] [7]
+Underfull \hbox (badness 10000) in paragraph at lines 118--119
+[]\OT1/cmr/m/n/10.95 Various, \OT1/cmr/m/it/10.95 https://www.eevblog.com/forum
+/projects/dreaded-
+ []
+
+
+Underfull \hbox (badness 10000) in paragraph at lines 118--119
+\OT1/cmr/m/it/10.95 alternator-whine-in-car-stereo/25/ \OT1/cmr/m/n/10.95 Re-tr
+ieved 2020-02-21. see
+ []
+
+
+Underfull \hbox (badness 10000) in paragraph at lines 118--119
+\OT1/cmr/m/n/10.95 also https://www.eevblog.com/forum/beginners/car-engine-sign
+al-
+ []
+
+
+Underfull \hbox (badness 10000) in paragraph at lines 121--122
+[]\OT1/cmr/m/it/10.95 https://partofthething.com/thoughts/building-a-low-pass-f
+ilter-to-
+ []
+
+[8] (./18.aux) ) 
+Here is how much of TeX's memory you used:
+ 2617 strings out of 494945
+ 41908 string characters out of 6181032
+ 96839 words of memory out of 5000000
+ 5901 multiletter control sequences out of 15000+600000
+ 10544 words of font info for 37 fonts, out of 8000000 for 9000
+ 14 hyphenation exceptions out of 8191
+ 39i,8n,39p,867b,211s stack positions out of 5000i,500n,10000p,200000b,80000s
+</usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/c
+mbx10.pfb></usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmbx12.
+pfb></usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmr10.pfb></u
+sr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmr12.pfb></usr/shar
+e/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmr6.pfb></usr/share/texliv
+e/texmf-dist/fonts/type1/public/amsfonts/cm/cmr8.pfb></usr/share/texlive/texmf-
+dist/fonts/type1/public/amsfonts/cm/cmr9.pfb></usr/share/texlive/texmf-dist/fon
+ts/type1/public/amsfonts/cm/cmsy10.pfb></usr/share/texlive/texmf-dist/fonts/typ
+e1/public/amsfonts/cm/cmti10.pfb></usr/share/texlive/texmf-dist/fonts/type1/pub
+lic/amsfonts/cm/cmtt10.pfb>
+Output written on 18.pdf (8 pages, 542902 bytes).
+PDF statistics:
+ 74 PDF objects out of 1000 (max. 8388607)
+ 50 compressed objects within 1 object stream
+ 0 named destinations out of 1000 (max. 500000)
+ 16 words of extra memory for PDF output out of 10000 (max. 10000000)
+

Car_Stereo_Replacement/docs/18.tex

@@ -0,0 +1,124 @@
+\documentclass[11pt]{article}
+%Gummi|065|=)
+\title{\textbf{Car Stereo Replacement}}
+\usepackage{graphicx,caption}
+%\author{Steak Electronics}
+\date{02/13/20}
+\begin{document}
+
+\maketitle
+
+\section{Overview}
+Replacing a car stereo. I could just go to ebay, and buy a used car stereo, but where's the fun in that? Let's DIY a car stereo from a PCB used as a frontplate, a connector for my vehicle, and an audio amplifier. I'll connect in signal from an audio player.
+\\
+
+\includegraphics[scale=0.4]{../pics/DSCN2180.JPG}
+\captionof{figure}{PCB rev 1}
+
+\section{Items Included}
+I thought I would include the following:
+\begin{itemize}
+\item Arduino Nano
+\item Voltage and Gnd Breakout
+\item I2C Display
+\item Voltage Readout (of BAT)
+\item Current Readout (being drawn)
+\item Amplifier ``Lvpin LP-838''
+\end{itemize}
+I also wanted to have the connectors that eurorack and synth designers use for mono audio cables, but the cables turned out too expensive. The current readout didn't work initially, and I haven't gotten to fixing it yet.
+\subsection{I2C OLED display}
+Just for fun, I bought an I2C oled display and am going to use it to display something.\footnote{It's an Arduino Uno, you can put almost anything on this.} Notes on this:
+Using the adafruit SSD1306 and GFX library (this procedure is well covered in other places), you can load an example sketch and get it running. First thing to change is to remove the Adafruit logo and replace it with my own. Let's do that.
+
+From https://design.goeszen.com/convert-image-for-oled-display.html
+\begin{verbatim}
+I'm on Linux here and found that the readily-available 
+ImageMagick package will do the trick for you without
+ any scripting. And runs on the CLI! Simple as that:
+
+    convert some_image.png some.image.mono
+\end{verbatim}
+That's efficient. But it didn't really work out. Too much work, I don't need it that bad. Have to convert it to something the c compiler can read. I instead, just deleted their logo. Good enough for now.
+\subsection{Internal AVR Temperature Sensor}
+
+I setup the code to read from the internal temp sensor on the duino. However there is also this:
+
+https://thecavepearlproject.org/2019/02/25/no-parts-temperature-measurement-with-arduino-pro-mini-to-0-005c-or-better/
+
+This would be something to do for more resolution. The built in sensor is not very good, so this above link would be great. Hack a day also covers it. 
+
+\section{Wiring Pinout is wrong on Internet - Cable has labels}
+I looked at the picture I have detailing the pinout of my car connector (Delco Delphi radio wiring diagram.jpg in resources). It's close, but not 100\% correct. I found that the cable itself has small text labels on each wire which explain which everything does. I didn't notice earlier, as I didn't look close enough (and no one mentioned this).
+
+\section{Arduino VReg Blowout}
+I had a knock off Arduino Nano, and the vreg blew out. I have some other vregs to replace it. I didn't have this problem with an Uno that I use as a ceiling dome light. Although that one is not left on as long, usually. 
+
+\section{Amplifier}
+The amplifier I used is one of the cheapest avialable on ebay. I'm not proud. I'm poor. I had to take it apart, and reseat the amplifier ICs as the tab was not making contact with the chassis for one of them. I also added thermal paste. This amp is underpowered for my car, and may need replacing. It gets a bit hot.
+
+Some other issues with this amplifier are that the output connectors can get pushed back, there is only one output connector option, and it must run on battery power, as a 12V 1A or 2A will not power it. Finally, there is a 6V DC bias on output. No output audio isolation, which means you get car noise.
+
+\section{AC Audio Coupling to Remove DC Noise from Auto}
+I had some fun with this one. Many videos on this in the video folder. I started with the speakers being directly fed by the amplifier. This worked, but there was some noise coming through. Cars are noisy, this is not surprising. I would've preferred the amplifier to isolate the outputs, but no luck... At this point, I considered two options to block DC and allow AC. 1) Use a transformer. 2) Use capacitors.\footnote{A third option would've been to use a second set of batteries, but that would be laborious.}
+
+\subsection{Ground Isolator}
+I had been given a Ground isolator, which was two small transformers on a pcb intended to pass audio from a car powered signal source into the car speakers. I tried this isolator on the output of the speakers, and while it worked, the volume was lower, and it was impractical. I knew as soon as I heard the volume, that the issue was an impedance matching problem. The transformers were too small. They were intended for signal sources, not amplifier outputs. Onto option \#2.
+\\
+
+\begin{center}
+\includegraphics[scale=0.35]{../pics/DSCN2610.JPG}
+\captionof{figure}{Ground Loop Isolator.}
+\end{center}
+\subsection{Capacitor Audio Coupling}
+My initial thoughts here were: ``Let's be careful and use non polarized caps''. I bought some 0.22uf and 0.022uf polyester film capacitors at Electronics Plus, the local radioshack replacement, and tried them. No sound. After adjusting the connectors on the amp (which were admittedly loose - it's easy to push them back on the amplifier if you are not careful) I found that the capacitors didn't work. One problem was evident in the oscope. I only used one capacitor on the + output of the speaker amp, but the Amp biases the signal 6 volts. So I needed two. After that was resolved, the signal came through on the output of the capacitor, as viewed on the scope, however there was no sound output. I tried the safe way. It's time to break some rules. 
+
+I grabbed some 1uf (electrolytic polarized) caps I had, and tried these. Again, no sound. Not giving up, I grabbed some 1000uf 'lytics, and tried once more. Now it worked.
+
+\subsubsection{Impedance / ESR of capacitors failing to pass enough power of signal}
+Capacitors are rated for impedance. Some data sheets also call this ESR, it appears after a quick look. It's either in there as impedance or ESR. It's not initially an issue if you are using the capacitor as a DC reservoir, but if you use it in an AC coupling situation then things get interesting. A high impedance, or ESR will block what a low one won't. In this example, it's as simple as the Amplfier either being able to power a speaker or not. Higher capacity caps will have lower impedance. See the picture. Other brands put impedance in a graph, or just call it impedance. 
+
+\includegraphics[scale=0.5]{../pics/esr_impedance_capacitance.png}
+\captionof{figure}{Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.}
+
+\subsubsection{Wikipedia on Impedance}
+
+\emph{In general, a capacitor is seen as a storage component for electric energy. But this is only one capacitor function. A capacitor can also act as an AC resistor. Especially aluminum electrolytic capacitors are used in many applications as a decoupling capacitors to filter or bypass undesired biased AC frequencies to the ground or for capacitive coupling of audio AC signals. Then the dielectric is used only for blocking DC. For such applications the AC resistance, the impedance is as important as the capacitance value. }
+\begin{verbatim} https://en.wikipedia.org/w/index.php\title=Aluminum_electrolytic
+_capacitor&oldid=940281525
+\end{verbatim}
+Essentially, what I learned today.
+
+\section{DIY Amp}
+I was flipping through Practical Electronics for Inventors\cite{Scherz}(page 959), when I came across an audio amplifier. He also gives one at the chapter on Semiconductors (pg. 467), although the former is more detailed. With a reasonably simple schematic available, and a high likelihood of it working, I say why not: let's build it up.
+
+I've noticed that the ``Lvpin LP-838'' amplifier I'm using is underpowered for my two front speakers \footnote{Although it seems it would work for one channel, so two of them might be enough. It's rated for 20W, so that is about 15-20W per channel req'd. It works at 20W for both, just that it heats up too much. Multiple ebay sellers have it misquoted at 200W. Just an extra 0, no biggie. Based on all this, it appears each channel of my car speaker needs about 15 watts to be on the safe side. The example schematic is 16 watts. Two should suffice.}, so I will make two of the provided 16 watt amps.
+
+\subsection{LM383 is Obsolete}
+That explains why I haven't heard of it. The chip is obsolete. Some sell it on ebay for about \$5 each.
+
+As a different route, could I use some other power amplifier op amp, with the same pinout? Hm... Aha, the LM1875 has the same pinout. Let's use that.\footnote{How did I find this? I searched Digikey for the LM383 sold by rochester, noted it was it the category of Linear - Amplifiers - Audio, chose that, then searched for everything in the same package (TO220-5). Came right up. If this hadn't worked, I would've wanted to try other sites: Farnells, Mouser, etc...}
+
+Will it work with the same schematic? Questionable. May still need to buy a LM383, along with the LM1875, as backup. I might also try a generic power op amp.
+
+Amplfiers are the expensive bom item here.
+
+\section{Noise remains with Speaker Isolation}
+I've isolated the speakers from DC with the caps, but noise remains. My next idea was a DC-DC isolated supply. But, I found two threads on eevblog forums\cite{eevblog}, and they recommend a power line filter (they also mention the isolated supply). A filter with a coil and cap (2200uf even low enough) I can quickly build up.
+
+I also want to fix up my portable CRO, I obtained the other day. That needs batteries.
+ 
+
+\section{References}
+\begin{thebibliography}{99}
+\bibitem{Scherz}
+  Paul Scherz, and Simon Monk,
+  \emph{Practical Electronics for Inventors}, fourth edition - 2016, McGraw Hill.
+
+\bibitem{eevblog}
+  Various, \emph{https://www.eevblog.com/forum/projects/dreaded-alternator-whine-in-car-stereo/25/} Retrieved 2020-02-21. see also https://www.eevblog.com/forum/beginners/car-engine-signal-interference-with-cell-phone/
+
+\bibitem{partofthe}
+  \emph{https://partofthething.com/thoughts/building-a-low-pass-filter-to-remove-alternator-whine-in-my-car/}. Picture guide and showing basic build in project box. Eevblog users mention you may be able to use the secondary of a transformer, to avoid building the coil.
+  \end{thebibliography}
+
+\end{document}

Car_Stereo_Replacement/docs/18.tex~

@@ -0,0 +1,123 @@
+\documentclass[11pt]{article}
+%Gummi|065|=)
+\title{\textbf{Car Stereo Replacement}}
+\usepackage{graphicx,caption}
+%\author{Steak Electronics}
+\date{02/13/20}
+\begin{document}
+
+\maketitle
+
+\section{Overview}
+Replacing a car stereo. I could just go to ebay, and buy a used car stereo, but where's the fun in that? Let's DIY a car stereo from a PCB used as a frontplate, a connector for my vehicle, and an audio amplifier. I'll connect in signal from an audio player.
+\\
+
+\includegraphics[scale=0.4]{../pics/DSCN2180.JPG}
+\captionof{figure}{PCB rev 1}
+
+\section{Items Included}
+I thought I would include the following:
+\begin{itemize}
+\item Arduino Nano
+\item Voltage and Gnd Breakout
+\item I2C Display
+\item Voltage Readout (of BAT)
+\item Current Readout (being drawn)
+\item Amplifier ``Lvpin LP-838''
+\end{itemize}
+I also wanted to have the connectors that eurorack and synth designers use for mono audio cables, but the cables turned out too expensive. The current readout didn't work initially, and I haven't gotten to fixing it yet.
+\subsection{I2C OLED display}
+Just for fun, I bought an I2C oled display and am going to use it to display something.\footnote{It's an Arduino Uno, you can put almost anything on this.} Notes on this:
+Using the adafruit SSD1306 and GFX library (this procedure is well covered in other places), you can load an example sketch and get it running. First thing to change is to remove the Adafruit logo and replace it with my own. Let's do that.
+
+From https://design.goeszen.com/convert-image-for-oled-display.html
+\begin{verbatim}
+I'm on Linux here and found that the readily-available 
+ImageMagick package will do the trick for you without
+ any scripting. And runs on the CLI! Simple as that:
+
+    convert some_image.png some.image.mono
+\end{verbatim}
+That's efficient. But it didn't really work out. Too much work, I don't need it that bad. Have to convert it to something the c compiler can read. I instead, just deleted their logo. Good enough for now.
+\subsection{Internal AVR Temperature Sensor}
+
+I setup the code to read from the internal temp sensor on the duino. However there is also this:
+
+https://thecavepearlproject.org/2019/02/25/no-parts-temperature-measurement-with-arduino-pro-mini-to-0-005c-or-better/
+
+This would be something to do for more resolution. The built in sensor is not very good, so this above link would be great. Hack a day also covers it. 
+
+\section{Wiring Pinout is wrong on Internet - Cable has labels}
+I looked at the picture I have detailing the pinout of my car connector (Delco Delphi radio wiring diagram.jpg in resources). It's close, but not 100\% correct. I found that the cable itself has small text labels on each wire which explain which everything does. I didn't notice earlier, as I didn't look close enough (and no one mentioned this).
+
+\section{Arduino VReg Blowout}
+I had a knock off Arduino Nano, and the vreg blew out. I have some other vregs to replace it. I didn't have this problem with an Uno that I use as a ceiling dome light. Although that one is not left on as long, usually. 
+
+\section{Amplifier}
+The amplifier I used is one of the cheapest avialable on ebay. I'm not proud. I'm poor. I had to take it apart, and reseat the amplifier ICs as the tab was not making contact with the chassis for one of them. I also added thermal paste. This amp is underpowered for my car, and may need replacing. It gets a bit hot.
+
+Some other issues with this amplifier are that the output connectors can get pushed back, there is only one output connector option, and it must run on battery power, as a 12V 1A or 2A will not power it. Finally, there is a 6V DC bias on output. No output audio isolation, which means you get car noise.
+
+\section{AC Audio Coupling to Remove DC Noise from Auto}
+I had some fun with this one. Many videos on this in the video folder. I started with the speakers being directly fed by the amplifier. This worked, but there was some noise coming through. Cars are noisy, this is not surprising. I would've preferred the amplifier to isolate the outputs, but no luck... At this point, I considered two options to block DC and allow AC. 1) Use a transformer. 2) Use capacitors.\footnote{A third option would've been to use a second set of batteries, but that would be laborious.}
+
+\subsection{Ground Isolator}
+I had been given a Ground isolator, which was two small transformers on a pcb intended to pass audio from a car powered signal source into the car speakers. I tried this isolator on the output of the speakers, and while it worked, the volume was lower, and it was impractical. I knew as soon as I heard the volume, that the issue was an impedance matching problem. The transformers were too small. They were intended for signal sources, not amplifier outputs. Onto option \#2.
+
+
+\includegraphics[scale=0.5]{../pics/DSCN2610.JPG}
+\captionof{figure}{Ground Loop Isolator.}
+
+\subsection{Capacitor Audio Coupling}
+My initial thoughts here were: ``Let's be careful and use non polarized caps''. I bought some 0.22uf and 0.022uf polyester film capacitors at Electronics Plus, the local radioshack replacement, and tried them. No sound. After adjusting the connectors on the amp (which were admittedly loose - it's easy to push them back on the amplifier if you are not careful) I found that the capacitors didn't work. One problem was evident in the oscope. I only used one capacitor on the + output of the speaker amp, but the Amp biases the signal 6 volts. So I needed two. After that was resolved, the signal came through on the output of the capacitor, as viewed on the scope, however there was no sound output. I tried the safe way. It's time to break some rules. 
+
+I grabbed some 1uf (electrolytic polarized) caps I had, and tried these. Again, no sound. Not giving up, I grabbed some 1000uf 'lytics, and tried once more. Now it worked.
+
+\subsubsection{Impedance / ESR of capacitors failing to pass enough power of signal}
+Capacitors are rated for impedance. Some data sheets also call this ESR, it appears after a quick look. It's either in there as impedance or ESR. It's not initially an issue if you are using the capacitor as a DC reservoir, but if you use it in an AC coupling situation then things get interesting. A high impedance, or ESR will block what a low one won't. In this example, it's as simple as the Amplfier either being able to power a speaker or not. Higher capacity caps will have lower impedance. See the picture. Other brands put impedance in a graph, or just call it impedance. 
+
+\includegraphics[scale=0.5]{../pics/esr_impedance_capacitance.png}
+\captionof{figure}{Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.}
+
+\subsubsection{Wikipedia on Impedance}
+
+\emph{In general, a capacitor is seen as a storage component for electric energy. But this is only one capacitor function. A capacitor can also act as an AC resistor. Especially aluminum electrolytic capacitors are used in many applications as a decoupling capacitors to filter or bypass undesired biased AC frequencies to the ground or for capacitive coupling of audio AC signals. Then the dielectric is used only for blocking DC. For such applications the AC resistance, the impedance is as important as the capacitance value. }
+\begin{verbatim} https://en.wikipedia.org/w/index.php\title=Aluminum_electrolytic
+_capacitor&oldid=940281525
+\end{verbatim}
+Essentially, what I learned today.
+
+\section{DIY Amp}
+I was flipping through Practical Electronics for Inventors\cite{Scherz}(page 959), when I came across an audio amplifier. He also gives one at the chapter on Semiconductors (pg. 467), although the former is more detailed. With a reasonably simple schematic available, and a high likelihood of it working, I say why not: let's build it up.
+
+I've noticed that the ``Lvpin LP-838'' amplifier I'm using is underpowered for my two front speakers \footnote{Although it seems it would work for one channel, so two of them might be enough. It's rated for 20W, so that is about 15-20W per channel req'd. It works at 20W for both, just that it heats up too much. Multiple ebay sellers have it misquoted at 200W. Just an extra 0, no biggie. Based on all this, it appears each channel of my car speaker needs about 15 watts to be on the safe side. The example schematic is 16 watts. Two should suffice.}, so I will make two of the provided 16 watt amps.
+
+\subsection{LM383 is Obsolete}
+That explains why I haven't heard of it. The chip is obsolete. Some sell it on ebay for about \$5 each.
+
+As a different route, could I use some other power amplifier op amp, with the same pinout? Hm... Aha, the LM1875 has the same pinout. Let's use that.\footnote{How did I find this? I searched Digikey for the LM383 sold by rochester, noted it was it the category of Linear - Amplifiers - Audio, chose that, then searched for everything in the same package (TO220-5). Came right up. If this hadn't worked, I would've wanted to try other sites: Farnells, Mouser, etc...}
+
+Will it work with the same schematic? Questionable. May still need to buy a LM383, along with the LM1875, as backup. I might also try a generic power op amp.
+
+Amplfiers are the expensive bom item here.
+
+\section{Noise remains with Speaker Isolation}
+I've isolated the speakers from DC with the caps, but noise remains. My next idea was a DC-DC isolated supply. But, I found two threads on eevblog forums\cite{eevblog}, and they recommend a power line filter (they also mention the isolated supply). A filter with a coil and cap (2200uf even low enough) I can quickly build up.
+
+I also want to fix up my portable CRO, I obtained the other day. That needs batteries.
+ 
+
+\section{References}
+\begin{thebibliography}{99}
+\bibitem{Scherz}
+  Paul Scherz, and Simon Monk,
+  \emph{Practical Electronics for Inventors}, fourth edition - 2016, McGraw Hill.
+
+\bibitem{eevblog}
+  Various, \emph{https://www.eevblog.com/forum/projects/dreaded-alternator-whine-in-car-stereo/25/} Retrieved 2020-02-21. see also https://www.eevblog.com/forum/beginners/car-engine-signal-interference-with-cell-phone/
+
+\bibitem{partofthe}
+  \emph{https://partofthething.com/thoughts/building-a-low-pass-filter-to-remove-alternator-whine-in-my-car/}. Picture guide and showing basic build in project box. Eevblog users mention you may be able to use the secondary of a transformer, to avoid building the coil.
+  \end{thebibliography}
+
+\end{document}

Car_Stereo_Replacement/docs/19.aux

@@ -0,0 +1,25 @@
+\relax 
+\@writefile{toc}{\contentsline {section}{\numberline {1}Overview}{1}}
+\@writefile{lof}{\contentsline {figure}{\numberline {1}{\ignorespaces PCB rev 1\relax }}{1}}
+\@writefile{toc}{\contentsline {section}{\numberline {2}Items Included}{2}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {2.1}I2C OLED display}{2}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {2.2}Internal AVR Temperature Sensor}{3}}
+\@writefile{toc}{\contentsline {section}{\numberline {3}Wiring Pinout is wrong on Internet - Cable has labels}{3}}
+\@writefile{toc}{\contentsline {section}{\numberline {4}Arduino VReg Blowout}{3}}
+\@writefile{toc}{\contentsline {section}{\numberline {5}Amplifier}{3}}
+\@writefile{toc}{\contentsline {section}{\numberline {6}AC Audio Coupling to Remove DC Noise from Auto}{4}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {6.1}Ground Isolator}{4}}
+\@writefile{lof}{\contentsline {figure}{\numberline {2}{\ignorespaces Ground Loop Isolator.\relax }}{4}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {6.2}Capacitor Audio Coupling}{5}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {6.2.1}Impedance / ESR of capacitors failing to pass enough power of signal}{5}}
+\citation{Scherz}
+\@writefile{lof}{\contentsline {figure}{\numberline {3}{\ignorespaces Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.\relax }}{6}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {6.2.2}Wikipedia on Impedance}{6}}
+\@writefile{toc}{\contentsline {section}{\numberline {7}DIY Amp}{6}}
+\citation{eevblog}
+\bibcite{Scherz}{1}
+\@writefile{toc}{\contentsline {subsection}{\numberline {7.1}LM383 is Obsolete}{7}}
+\@writefile{toc}{\contentsline {section}{\numberline {8}Noise remains with Speaker Isolation}{7}}
+\bibcite{eevblog}{2}
+\bibcite{partofthe}{3}
+\@writefile{toc}{\contentsline {section}{\numberline {9}References}{8}}

Car_Stereo_Replacement/docs/19.log

@@ -0,0 +1,278 @@
+This is pdfTeX, Version 3.14159265-2.6-1.40.17 (TeX Live 2016/Debian) (preloaded format=pdflatex 2019.8.17)  5 MAR 2020 23:53
+entering extended mode
+ restricted \write18 enabled.
+ %&-line parsing enabled.
+**/home/layoutdev/Desktop/code/documentation_general/Electronics_Projects_2019/
+Car_Stereo_Replacement/docs/19.tex
+
+(/home/layoutdev/Desktop/code/documentation_general/Electronics_Projects_2019/C
+ar_Stereo_Replacement/docs/19.tex
+LaTeX2e <2017/01/01> patch level 3
+Babel <3.9r> and hyphenation patterns for 3 language(s) loaded.
+(/usr/share/texlive/texmf-dist/tex/latex/base/article.cls
+Document Class: article 2014/09/29 v1.4h Standard LaTeX document class
+(/usr/share/texlive/texmf-dist/tex/latex/base/size11.clo
+File: size11.clo 2014/09/29 v1.4h Standard LaTeX file (size option)
+)
+\c@part=\count79
+\c@section=\count80
+\c@subsection=\count81
+\c@subsubsection=\count82
+\c@paragraph=\count83
+\c@subparagraph=\count84
+\c@figure=\count85
+\c@table=\count86
+\abovecaptionskip=\skip41
+\belowcaptionskip=\skip42
+\bibindent=\dimen102
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/graphicx.sty
+Package: graphicx 2014/10/28 v1.0g Enhanced LaTeX Graphics (DPC,SPQR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/keyval.sty
+Package: keyval 2014/10/28 v1.15 key=value parser (DPC)
+\KV@toks@=\toks14
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/graphics.sty
+Package: graphics 2016/10/09 v1.0u Standard LaTeX Graphics (DPC,SPQR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/trig.sty
+Package: trig 2016/01/03 v1.10 sin cos tan (DPC)
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics-cfg/graphics.cfg
+File: graphics.cfg 2016/06/04 v1.11 sample graphics configuration
+)
+Package graphics Info: Driver file: pdftex.def on input line 99.
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics-def/pdftex.def
+File: pdftex.def 2017/01/12 v0.06k Graphics/color for pdfTeX
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/infwarerr.sty
+Package: infwarerr 2016/05/16 v1.4 Providing info/warning/error messages (HO)
+)
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ltxcmds.sty
+Package: ltxcmds 2016/05/16 v1.23 LaTeX kernel commands for general use (HO)
+)
+\Gread@gobject=\count87
+))
+\Gin@req@height=\dimen103
+\Gin@req@width=\dimen104
+)
+(/usr/share/texlive/texmf-dist/tex/latex/caption/caption.sty
+Package: caption 2016/02/21 v3.3-144 Customizing captions (AR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/caption/caption3.sty
+Package: caption3 2016/05/22 v1.7-166 caption3 kernel (AR)
+Package caption3 Info: TeX engine: e-TeX on input line 67.
+\captionmargin=\dimen105
+\captionmargin@=\dimen106
+\captionwidth=\dimen107
+\caption@tempdima=\dimen108
+\caption@indent=\dimen109
+\caption@parindent=\dimen110
+\caption@hangindent=\dimen111
+)
+\c@ContinuedFloat=\count88
+) (./19.aux)
+\openout1 = `19.aux'.
+
+LaTeX Font Info:    Checking defaults for OML/cmm/m/it on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for T1/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OT1/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OMS/cmsy/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OMX/cmex/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for U/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+
+(/usr/share/texlive/texmf-dist/tex/context/base/mkii/supp-pdf.mkii
+[Loading MPS to PDF converter (version 2006.09.02).]
+\scratchcounter=\count89
+\scratchdimen=\dimen112
+\scratchbox=\box26
+\nofMPsegments=\count90
+\nofMParguments=\count91
+\everyMPshowfont=\toks15
+\MPscratchCnt=\count92
+\MPscratchDim=\dimen113
+\MPnumerator=\count93
+\makeMPintoPDFobject=\count94
+\everyMPtoPDFconversion=\toks16
+) (/usr/share/texlive/texmf-dist/tex/generic/oberdiek/pdftexcmds.sty
+Package: pdftexcmds 2016/05/21 v0.22 Utility functions of pdfTeX for LuaTeX (HO
+)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ifluatex.sty
+Package: ifluatex 2016/05/16 v1.4 Provides the ifluatex switch (HO)
+Package ifluatex Info: LuaTeX not detected.
+)
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ifpdf.sty
+Package: ifpdf 2016/05/14 v3.1 Provides the ifpdf switch
+)
+Package pdftexcmds Info: LuaTeX not detected.
+Package pdftexcmds Info: \pdf@primitive is available.
+Package pdftexcmds Info: \pdf@ifprimitive is available.
+Package pdftexcmds Info: \pdfdraftmode found.
+)
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/epstopdf-base.sty
+Package: epstopdf-base 2016/05/15 v2.6 Base part for package epstopdf
+
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/grfext.sty
+Package: grfext 2016/05/16 v1.2 Manage graphics extensions (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/kvdefinekeys.sty
+Package: kvdefinekeys 2016/05/16 v1.4 Define keys (HO)
+))
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/kvoptions.sty
+Package: kvoptions 2016/05/16 v3.12 Key value format for package options (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/kvsetkeys.sty
+Package: kvsetkeys 2016/05/16 v1.17 Key value parser (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/etexcmds.sty
+Package: etexcmds 2016/05/16 v1.6 Avoid name clashes with e-TeX commands (HO)
+Package etexcmds Info: Could not find \expanded.
+(etexcmds)             That can mean that you are not using pdfTeX 1.50 or
+(etexcmds)             that some package has redefined \expanded.
+(etexcmds)             In the latter case, load this package earlier.
+)))
+Package epstopdf-base Info: Redefining graphics rule for `.eps' on input line 4
+38.
+Package grfext Info: Graphics extension search list:
+(grfext)             [.png,.pdf,.jpg,.mps,.jpeg,.jbig2,.jb2,.PNG,.PDF,.JPG,.JPE
+G,.JBIG2,.JB2,.eps]
+(grfext)             \AppendGraphicsExtensions on input line 456.
+
+(/usr/share/texlive/texmf-dist/tex/latex/latexconfig/epstopdf-sys.cfg
+File: epstopdf-sys.cfg 2010/07/13 v1.3 Configuration of (r)epstopdf for TeX Liv
+e
+))
+Package caption Info: Begin \AtBeginDocument code.
+Package caption Info: End \AtBeginDocument code.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <12> on input line 9.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <8> on input line 9.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <6> on input line 9.
+
+
+LaTeX Warning: No \author given.
+
+
+Underfull \hbox (badness 10000) in paragraph at lines 12--14
+
+ []
+
+<../pics/DSCN2180.JPG, id=1, 803.0pt x 602.25pt>
+File: ../pics/DSCN2180.JPG Graphic file (type jpg)
+ <use ../pics/DSCN2180.JPG>
+Package pdftex.def Info: ../pics/DSCN2180.JPG used on input line 15.
+(pdftex.def)             Requested size: 321.1943pt x 240.89572pt.
+
+
+Package caption Warning: \captionsetup{type*=...} or \captionof
+(caption)                outside box or environment on input line 16.
+See the caption package documentation for explanation.
+
+[1
+
+{/var/lib/texmf/fonts/map/pdftex/updmap/pdftex.map} <../pics/DSCN2180.JPG>]
+LaTeX Font Info:    Try loading font information for OMS+cmr on input line 21.
+
+(/usr/share/texlive/texmf-dist/tex/latex/base/omscmr.fd
+File: omscmr.fd 2014/09/29 v2.5h Standard LaTeX font definitions
+)
+LaTeX Font Info:    Font shape `OMS/cmr/m/n' in size <10.95> not available
+(Font)              Font shape `OMS/cmsy/m/n' tried instead on input line 21.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <10.95> on input line 30.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <9> on input line 30.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <5> on input line 30.
+
+Underfull \hbox (badness 10000) in paragraph at lines 46--47
+[]\OT1/cmr/m/n/10.95 https://thecavepearlproject.org/2019/02/25/no-parts-temper
+ature-
+ []
+
+[2] [3]
+Underfull \hbox (badness 10000) in paragraph at lines 65--67
+
+ []
+
+<../pics/DSCN2610.JPG, id=21, 803.0pt x 602.25pt>
+File: ../pics/DSCN2610.JPG Graphic file (type jpg)
+ <use ../pics/DSCN2610.JPG>
+Package pdftex.def Info: ../pics/DSCN2610.JPG used on input line 69.
+(pdftex.def)             Requested size: 281.05421pt x 210.79065pt.
+
+[4 <../pics/DSCN2610.JPG>]
+<../pics/esr_impedance_capacitance.png, id=25, 697.10437pt x 421.69917pt>
+File: ../pics/esr_impedance_capacitance.png Graphic file (type png)
+
+<use ../pics/esr_impedance_capacitance.png>
+Package pdftex.def Info: ../pics/esr_impedance_capacitance.png used on input li
+ne 80.
+(pdftex.def)             Requested size: 348.55133pt x 210.84906pt.
+ [5]
+Overfull \hbox (13.6647pt too wide) in paragraph at lines 88--88
+[] \OT1/cmtt/m/n/10.95 https://en.wikipedia.org/w/index.php\title=Aluminum_elec
+trolytic 
+ []
+
+[6 <../pics/esr_impedance_capacitance.png (PNG copy)>] [7]
+Underfull \hbox (badness 10000) in paragraph at lines 118--119
+[]\OT1/cmr/m/n/10.95 Various, \OT1/cmr/m/it/10.95 https://www.eevblog.com/forum
+/projects/dreaded-
+ []
+
+
+Underfull \hbox (badness 10000) in paragraph at lines 118--119
+\OT1/cmr/m/it/10.95 alternator-whine-in-car-stereo/25/ \OT1/cmr/m/n/10.95 Re-tr
+ieved 2020-02-21. see
+ []
+
+
+Underfull \hbox (badness 10000) in paragraph at lines 118--119
+\OT1/cmr/m/n/10.95 also https://www.eevblog.com/forum/beginners/car-engine-sign
+al-
+ []
+
+
+Underfull \hbox (badness 10000) in paragraph at lines 121--122
+[]\OT1/cmr/m/it/10.95 https://partofthething.com/thoughts/building-a-low-pass-f
+ilter-to-
+ []
+
+[8] (./19.aux) ) 
+Here is how much of TeX's memory you used:
+ 2617 strings out of 494945
+ 41908 string characters out of 6181032
+ 96839 words of memory out of 5000000
+ 5901 multiletter control sequences out of 15000+600000
+ 10544 words of font info for 37 fonts, out of 8000000 for 9000
+ 14 hyphenation exceptions out of 8191
+ 39i,8n,39p,867b,211s stack positions out of 5000i,500n,10000p,200000b,80000s
+</usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/c
+mbx10.pfb></usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmbx12.
+pfb></usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmr10.pfb></u
+sr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmr12.pfb></usr/shar
+e/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmr6.pfb></usr/share/texliv
+e/texmf-dist/fonts/type1/public/amsfonts/cm/cmr8.pfb></usr/share/texlive/texmf-
+dist/fonts/type1/public/amsfonts/cm/cmr9.pfb></usr/share/texlive/texmf-dist/fon
+ts/type1/public/amsfonts/cm/cmsy10.pfb></usr/share/texlive/texmf-dist/fonts/typ
+e1/public/amsfonts/cm/cmti10.pfb></usr/share/texlive/texmf-dist/fonts/type1/pub
+lic/amsfonts/cm/cmtt10.pfb>
+Output written on 19.pdf (8 pages, 542902 bytes).
+PDF statistics:
+ 74 PDF objects out of 1000 (max. 8388607)
+ 50 compressed objects within 1 object stream
+ 0 named destinations out of 1000 (max. 500000)
+ 16 words of extra memory for PDF output out of 10000 (max. 10000000)
+

Car_Stereo_Replacement/docs/19.tex

@@ -0,0 +1,124 @@
+\documentclass[11pt]{article}
+%Gummi|065|=)
+\title{\textbf{Car Stereo Replacement}}
+\usepackage{graphicx,caption}
+%\author{Steak Electronics}
+\date{02/13/20}
+\begin{document}
+
+\maketitle
+
+\section{Overview}
+Replacing a car stereo. I could just go to ebay, and buy a used car stereo, but where's the fun in that? Let's DIY a car stereo from a PCB used as a frontplate, a connector for my vehicle, and an audio amplifier. I'll connect in signal from an audio player.
+\\
+
+\includegraphics[scale=0.4]{../pics/DSCN2180.JPG}
+\captionof{figure}{PCB rev 1}
+
+\section{Items Included}
+I thought I would include the following:
+\begin{itemize}
+\item Arduino Nano
+\item Voltage and Gnd Breakout
+\item I2C Display
+\item Voltage Readout (of BAT)
+\item Current Readout (being drawn)
+\item Amplifier ``Lvpin LP-838''
+\end{itemize}
+I also wanted to have the connectors that eurorack and synth designers use for mono audio cables, but the cables turned out too expensive. The current readout didn't work initially, and I haven't gotten to fixing it yet.
+\subsection{I2C OLED display}
+Just for fun, I bought an I2C oled display and am going to use it to display something.\footnote{It's an Arduino Uno, you can put almost anything on this.} Notes on this:
+Using the adafruit SSD1306 and GFX library (this procedure is well covered in other places), you can load an example sketch and get it running. First thing to change is to remove the Adafruit logo and replace it with my own. Let's do that.
+
+From https://design.goeszen.com/convert-image-for-oled-display.html
+\begin{verbatim}
+I'm on Linux here and found that the readily-available 
+ImageMagick package will do the trick for you without
+ any scripting. And runs on the CLI! Simple as that:
+
+    convert some_image.png some.image.mono
+\end{verbatim}
+That's efficient. But it didn't really work out. Too much work, I don't need it that bad. Have to convert it to something the c compiler can read. I instead, just deleted their logo. Good enough for now.
+\subsection{Internal AVR Temperature Sensor}
+
+I setup the code to read from the internal temp sensor on the duino. However there is also this:
+
+https://thecavepearlproject.org/2019/02/25/no-parts-temperature-measurement-with-arduino-pro-mini-to-0-005c-or-better/
+
+This would be something to do for more resolution. The built in sensor is not very good, so this above link would be great. Hack a day also covers it. 
+
+\section{Wiring Pinout is wrong on Internet - Cable has labels}
+I looked at the picture I have detailing the pinout of my car connector (Delco Delphi radio wiring diagram.jpg in resources). It's close, but not 100\% correct. I found that the cable itself has small text labels on each wire which explain which everything does. I didn't notice earlier, as I didn't look close enough (and no one mentioned this).
+
+\section{Arduino VReg Blowout}
+I had a knock off Arduino Nano, and the vreg blew out. I have some other vregs to replace it. I didn't have this problem with an Uno that I use as a ceiling dome light. Although that one is not left on as long, usually. 
+
+\section{Amplifier}
+The amplifier I used is one of the cheapest avialable on ebay. I'm not proud. I'm poor. I had to take it apart, and reseat the amplifier ICs as the tab was not making contact with the chassis for one of them. I also added thermal paste. This amp is underpowered for my car, and may need replacing. It gets a bit hot.
+
+Some other issues with this amplifier are that the output connectors can get pushed back, there is only one output connector option, and it must run on battery power, as a 12V 1A or 2A will not power it. Finally, there is a 6V DC bias on output. No output audio isolation, which means you get car noise.
+
+\section{AC Audio Coupling to Remove DC Noise from Auto}
+I had some fun with this one. Many videos on this in the video folder. I started with the speakers being directly fed by the amplifier. This worked, but there was some noise coming through. Cars are noisy, this is not surprising. I would've preferred the amplifier to isolate the outputs, but no luck... At this point, I considered two options to block DC and allow AC. 1) Use a transformer. 2) Use capacitors.\footnote{A third option would've been to use a second set of batteries, but that would be laborious.}
+
+\subsection{Ground Isolator}
+I had been given a Ground isolator, which was two small transformers on a pcb intended to pass audio from a car powered signal source into the car speakers. I tried this isolator on the output of the speakers, and while it worked, the volume was lower, and it was impractical. I knew as soon as I heard the volume, that the issue was an impedance matching problem. The transformers were too small. They were intended for signal sources, not amplifier outputs. Onto option \#2.
+\\
+
+\begin{center}
+\includegraphics[scale=0.35]{../pics/DSCN2610.JPG}
+\captionof{figure}{Ground Loop Isolator.}
+\end{center}
+\subsection{Capacitor Audio Coupling}
+My initial thoughts here were: ``Let's be careful and use non polarized caps''. I bought some 0.22uf and 0.022uf polyester film capacitors at Electronics Plus, the local radioshack replacement, and tried them. No sound. After adjusting the connectors on the amp (which were admittedly loose - it's easy to push them back on the amplifier if you are not careful) I found that the capacitors didn't work. One problem was evident in the oscope. I only used one capacitor on the + output of the speaker amp, but the Amp biases the signal 6 volts. So I needed two. After that was resolved, the signal came through on the output of the capacitor, as viewed on the scope, however there was no sound output. I tried the safe way. It's time to break some rules. 
+
+I grabbed some 1uf (electrolytic polarized) caps I had, and tried these. Again, no sound. Not giving up, I grabbed some 1000uf 'lytics, and tried once more. Now it worked.
+
+\subsubsection{Impedance / ESR of capacitors failing to pass enough power of signal}
+Capacitors are rated for impedance. Some data sheets also call this ESR, it appears after a quick look. It's either in there as impedance or ESR. It's not initially an issue if you are using the capacitor as a DC reservoir, but if you use it in an AC coupling situation then things get interesting. A high impedance, or ESR will block what a low one won't. In this example, it's as simple as the Amplfier either being able to power a speaker or not. Higher capacity caps will have lower impedance. See the picture. Other brands put impedance in a graph, or just call it impedance. 
+
+\includegraphics[scale=0.5]{../pics/esr_impedance_capacitance.png}
+\captionof{figure}{Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.}
+
+\subsubsection{Wikipedia on Impedance}
+
+\emph{In general, a capacitor is seen as a storage component for electric energy. But this is only one capacitor function. A capacitor can also act as an AC resistor. Especially aluminum electrolytic capacitors are used in many applications as a decoupling capacitors to filter or bypass undesired biased AC frequencies to the ground or for capacitive coupling of audio AC signals. Then the dielectric is used only for blocking DC. For such applications the AC resistance, the impedance is as important as the capacitance value. }
+\begin{verbatim} https://en.wikipedia.org/w/index.php\title=Aluminum_electrolytic
+_capacitor&oldid=940281525
+\end{verbatim}
+Essentially, what I learned today.
+
+\section{DIY Amp}
+I was flipping through Practical Electronics for Inventors\cite{Scherz}(page 959), when I came across an audio amplifier. He also gives one at the chapter on Semiconductors (pg. 467), although the former is more detailed. With a reasonably simple schematic available, and a high likelihood of it working, I say why not: let's build it up.
+
+I've noticed that the ``Lvpin LP-838'' amplifier I'm using is underpowered for my two front speakers \footnote{Although it seems it would work for one channel, so two of them might be enough. It's rated for 20W, so that is about 15-20W per channel req'd. It works at 20W for both, just that it heats up too much. Multiple ebay sellers have it misquoted at 200W. Just an extra 0, no biggie. Based on all this, it appears each channel of my car speaker needs about 15 watts to be on the safe side. The example schematic is 16 watts. Two should suffice.}, so I will make two of the provided 16 watt amps.
+
+\subsection{LM383 is Obsolete}
+That explains why I haven't heard of it. The chip is obsolete. Some sell it on ebay for about \$5 each.
+
+As a different route, could I use some other power amplifier op amp, with the same pinout? Hm... Aha, the LM1875 has the same pinout. Let's use that.\footnote{How did I find this? I searched Digikey for the LM383 sold by rochester, noted it was it the category of Linear - Amplifiers - Audio, chose that, then searched for everything in the same package (TO220-5). Came right up. If this hadn't worked, I would've wanted to try other sites: Farnells, Mouser, etc...}
+
+Will it work with the same schematic? Questionable. May still need to buy a LM383, along with the LM1875, as backup. I might also try a generic power op amp.
+
+Amplfiers are the expensive bom item here.
+
+\section{Noise remains with Speaker Isolation}
+I've isolated the speakers from DC with the caps, but noise remains. My next idea was a DC-DC isolated supply. But, I found two threads on eevblog forums\cite{eevblog}, and they recommend a power line filter (they also mention the isolated supply). A filter with a coil and cap (2200uf even low enough) I can quickly build up.
+
+I also want to fix up my portable CRO, I obtained the other day. That needs batteries.
+ 
+
+\section{References}
+\begin{thebibliography}{99}
+\bibitem{Scherz}
+  Paul Scherz, and Simon Monk,
+  \emph{Practical Electronics for Inventors}, fourth edition - 2016, McGraw Hill.
+
+\bibitem{eevblog}
+  Various, \emph{https://www.eevblog.com/forum/projects/dreaded-alternator-whine-in-car-stereo/25/} Retrieved 2020-02-21. see also https://www.eevblog.com/forum/beginners/car-engine-signal-interference-with-cell-phone/
+
+\bibitem{partofthe}
+  \emph{https://partofthething.com/thoughts/building-a-low-pass-filter-to-remove-alternator-whine-in-my-car/}. Picture guide and showing basic build in project box. Eevblog users mention you may be able to use the secondary of a transformer, to avoid building the coil.
+  \end{thebibliography}
+
+\end{document}

Car_Stereo_Replacement/docs/20.aux

@@ -0,0 +1,25 @@
+\relax 
+\@writefile{toc}{\contentsline {section}{\numberline {1}Car Stereo Replacement}{1}}
+\@writefile{lof}{\contentsline {figure}{\numberline {1}{\ignorespaces PCB rev 1\relax }}{1}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.1}Items Included}{2}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.1.1}I2C OLED display}{2}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.1.2}Internal AVR Temperature Sensor}{3}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.2}Wiring Pinout is wrong on Internet - Cable has labels}{3}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.3}Arduino VReg Blowout}{3}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.4}Amplifier}{3}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.5}AC Audio Coupling to Remove DC Noise from Auto}{3}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.5.1}Ground Isolator}{4}}
+\@writefile{lof}{\contentsline {figure}{\numberline {2}{\ignorespaces Ground Loop Isolator.\relax }}{4}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.5.2}Capacitor Audio Coupling}{4}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.5.3}Impedance / ESR of capacitors failing to pass enough power of signal}{5}}
+\@writefile{lof}{\contentsline {figure}{\numberline {3}{\ignorespaces Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.\relax }}{5}}
+\citation{Scherz}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.5.4}Wikipedia on Impedance}{6}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.6}DIY Amp}{6}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.6.1}LM383 is Obsolete}{6}}
+\citation{eevblog}
+\bibcite{Scherz}{1}
+\bibcite{eevblog}{2}
+\bibcite{partofthe}{3}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.7}Noise remains with Speaker Isolation}{7}}
+\@writefile{toc}{\contentsline {section}{\numberline {2}References}{7}}

Car_Stereo_Replacement/docs/20.log

@@ -0,0 +1,282 @@
+This is pdfTeX, Version 3.14159265-2.6-1.40.17 (TeX Live 2016/Debian) (preloaded format=pdflatex 2019.8.17)  5 MAR 2020 23:55
+entering extended mode
+ restricted \write18 enabled.
+ %&-line parsing enabled.
+**/home/layoutdev/Desktop/code/documentation_general/Electronics_Projects_2019/
+Car_Stereo_Replacement/docs/20.tex
+
+(/home/layoutdev/Desktop/code/documentation_general/Electronics_Projects_2019/C
+ar_Stereo_Replacement/docs/20.tex
+LaTeX2e <2017/01/01> patch level 3
+Babel <3.9r> and hyphenation patterns for 3 language(s) loaded.
+(/usr/share/texlive/texmf-dist/tex/latex/base/article.cls
+Document Class: article 2014/09/29 v1.4h Standard LaTeX document class
+(/usr/share/texlive/texmf-dist/tex/latex/base/size11.clo
+File: size11.clo 2014/09/29 v1.4h Standard LaTeX file (size option)
+)
+\c@part=\count79
+\c@section=\count80
+\c@subsection=\count81
+\c@subsubsection=\count82
+\c@paragraph=\count83
+\c@subparagraph=\count84
+\c@figure=\count85
+\c@table=\count86
+\abovecaptionskip=\skip41
+\belowcaptionskip=\skip42
+\bibindent=\dimen102
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/graphicx.sty
+Package: graphicx 2014/10/28 v1.0g Enhanced LaTeX Graphics (DPC,SPQR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/keyval.sty
+Package: keyval 2014/10/28 v1.15 key=value parser (DPC)
+\KV@toks@=\toks14
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/graphics.sty
+Package: graphics 2016/10/09 v1.0u Standard LaTeX Graphics (DPC,SPQR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/trig.sty
+Package: trig 2016/01/03 v1.10 sin cos tan (DPC)
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics-cfg/graphics.cfg
+File: graphics.cfg 2016/06/04 v1.11 sample graphics configuration
+)
+Package graphics Info: Driver file: pdftex.def on input line 99.
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics-def/pdftex.def
+File: pdftex.def 2017/01/12 v0.06k Graphics/color for pdfTeX
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/infwarerr.sty
+Package: infwarerr 2016/05/16 v1.4 Providing info/warning/error messages (HO)
+)
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ltxcmds.sty
+Package: ltxcmds 2016/05/16 v1.23 LaTeX kernel commands for general use (HO)
+)
+\Gread@gobject=\count87
+))
+\Gin@req@height=\dimen103
+\Gin@req@width=\dimen104
+)
+(/usr/share/texlive/texmf-dist/tex/latex/caption/caption.sty
+Package: caption 2016/02/21 v3.3-144 Customizing captions (AR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/caption/caption3.sty
+Package: caption3 2016/05/22 v1.7-166 caption3 kernel (AR)
+Package caption3 Info: TeX engine: e-TeX on input line 67.
+\captionmargin=\dimen105
+\captionmargin@=\dimen106
+\captionwidth=\dimen107
+\caption@tempdima=\dimen108
+\caption@indent=\dimen109
+\caption@parindent=\dimen110
+\caption@hangindent=\dimen111
+)
+\c@ContinuedFloat=\count88
+) (./20.aux)
+\openout1 = `20.aux'.
+
+LaTeX Font Info:    Checking defaults for OML/cmm/m/it on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for T1/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OT1/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OMS/cmsy/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OMX/cmex/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for U/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+
+(/usr/share/texlive/texmf-dist/tex/context/base/mkii/supp-pdf.mkii
+[Loading MPS to PDF converter (version 2006.09.02).]
+\scratchcounter=\count89
+\scratchdimen=\dimen112
+\scratchbox=\box26
+\nofMPsegments=\count90
+\nofMParguments=\count91
+\everyMPshowfont=\toks15
+\MPscratchCnt=\count92
+\MPscratchDim=\dimen113
+\MPnumerator=\count93
+\makeMPintoPDFobject=\count94
+\everyMPtoPDFconversion=\toks16
+) (/usr/share/texlive/texmf-dist/tex/generic/oberdiek/pdftexcmds.sty
+Package: pdftexcmds 2016/05/21 v0.22 Utility functions of pdfTeX for LuaTeX (HO
+)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ifluatex.sty
+Package: ifluatex 2016/05/16 v1.4 Provides the ifluatex switch (HO)
+Package ifluatex Info: LuaTeX not detected.
+)
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ifpdf.sty
+Package: ifpdf 2016/05/14 v3.1 Provides the ifpdf switch
+)
+Package pdftexcmds Info: LuaTeX not detected.
+Package pdftexcmds Info: \pdf@primitive is available.
+Package pdftexcmds Info: \pdf@ifprimitive is available.
+Package pdftexcmds Info: \pdfdraftmode found.
+)
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/epstopdf-base.sty
+Package: epstopdf-base 2016/05/15 v2.6 Base part for package epstopdf
+
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/grfext.sty
+Package: grfext 2016/05/16 v1.2 Manage graphics extensions (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/kvdefinekeys.sty
+Package: kvdefinekeys 2016/05/16 v1.4 Define keys (HO)
+))
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/kvoptions.sty
+Package: kvoptions 2016/05/16 v3.12 Key value format for package options (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/kvsetkeys.sty
+Package: kvsetkeys 2016/05/16 v1.17 Key value parser (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/etexcmds.sty
+Package: etexcmds 2016/05/16 v1.6 Avoid name clashes with e-TeX commands (HO)
+Package etexcmds Info: Could not find \expanded.
+(etexcmds)             That can mean that you are not using pdfTeX 1.50 or
+(etexcmds)             that some package has redefined \expanded.
+(etexcmds)             In the latter case, load this package earlier.
+)))
+Package epstopdf-base Info: Redefining graphics rule for `.eps' on input line 4
+38.
+Package grfext Info: Graphics extension search list:
+(grfext)             [.png,.pdf,.jpg,.mps,.jpeg,.jbig2,.jb2,.PNG,.PDF,.JPG,.JPE
+G,.JBIG2,.JB2,.eps]
+(grfext)             \AppendGraphicsExtensions on input line 456.
+
+(/usr/share/texlive/texmf-dist/tex/latex/latexconfig/epstopdf-sys.cfg
+File: epstopdf-sys.cfg 2010/07/13 v1.3 Configuration of (r)epstopdf for TeX Liv
+e
+))
+Package caption Info: Begin \AtBeginDocument code.
+Package caption Info: End \AtBeginDocument code.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <12> on input line 9.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <8> on input line 9.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <6> on input line 9.
+
+
+LaTeX Warning: No \author given.
+
+No file 20.toc.
+\tf@toc=\write3
+\openout3 = `20.toc'.
+
+
+Underfull \hbox (badness 10000) in paragraph at lines 13--15
+
+ []
+
+<../pics/DSCN2180.JPG, id=1, 803.0pt x 602.25pt>
+File: ../pics/DSCN2180.JPG Graphic file (type jpg)
+ <use ../pics/DSCN2180.JPG>
+Package pdftex.def Info: ../pics/DSCN2180.JPG used on input line 16.
+(pdftex.def)             Requested size: 321.1943pt x 240.89572pt.
+
+
+Package caption Warning: \captionsetup{type*=...} or \captionof
+(caption)                outside box or environment on input line 17.
+See the caption package documentation for explanation.
+
+[1
+
+{/var/lib/texmf/fonts/map/pdftex/updmap/pdftex.map} <../pics/DSCN2180.JPG>]
+LaTeX Font Info:    Try loading font information for OMS+cmr on input line 22.
+
+(/usr/share/texlive/texmf-dist/tex/latex/base/omscmr.fd
+File: omscmr.fd 2014/09/29 v2.5h Standard LaTeX font definitions
+)
+LaTeX Font Info:    Font shape `OMS/cmr/m/n' in size <10.95> not available
+(Font)              Font shape `OMS/cmsy/m/n' tried instead on input line 22.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <10.95> on input line 31.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <9> on input line 31.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <5> on input line 31.
+
+Underfull \hbox (badness 10000) in paragraph at lines 47--48
+[]\OT1/cmr/m/n/10.95 https://thecavepearlproject.org/2019/02/25/no-parts-temper
+ature-
+ []
+
+[2] [3]
+Underfull \hbox (badness 10000) in paragraph at lines 66--68
+
+ []
+
+<../pics/DSCN2610.JPG, id=22, 803.0pt x 602.25pt>
+File: ../pics/DSCN2610.JPG Graphic file (type jpg)
+ <use ../pics/DSCN2610.JPG>
+Package pdftex.def Info: ../pics/DSCN2610.JPG used on input line 70.
+(pdftex.def)             Requested size: 281.05421pt x 210.79065pt.
+
+[4 <../pics/DSCN2610.JPG>]
+<../pics/esr_impedance_capacitance.png, id=26, 697.10437pt x 421.69917pt>
+File: ../pics/esr_impedance_capacitance.png Graphic file (type png)
+
+<use ../pics/esr_impedance_capacitance.png>
+Package pdftex.def Info: ../pics/esr_impedance_capacitance.png used on input li
+ne 81.
+(pdftex.def)             Requested size: 348.55133pt x 210.84906pt.
+ [5 <../pics/esr_impedance_capacitance.png (PNG copy)>]
+Overfull \hbox (13.6647pt too wide) in paragraph at lines 89--89
+[] \OT1/cmtt/m/n/10.95 https://en.wikipedia.org/w/index.php\title=Aluminum_elec
+trolytic 
+ []
+
+[6]
+Underfull \hbox (badness 10000) in paragraph at lines 121--122
+[]\OT1/cmr/m/n/10.95 Various, \OT1/cmr/m/it/10.95 https://www.eevblog.com/forum
+/projects/dreaded-
+ []
+
+
+Underfull \hbox (badness 10000) in paragraph at lines 121--122
+\OT1/cmr/m/it/10.95 alternator-whine-in-car-stereo/25/ \OT1/cmr/m/n/10.95 Re-tr
+ieved 2020-02-21. see
+ []
+
+
+Underfull \hbox (badness 10000) in paragraph at lines 121--122
+\OT1/cmr/m/n/10.95 also https://www.eevblog.com/forum/beginners/car-engine-sign
+al-
+ []
+
+
+Underfull \hbox (badness 10000) in paragraph at lines 124--125
+[]\OT1/cmr/m/it/10.95 https://partofthething.com/thoughts/building-a-low-pass-f
+ilter-to-
+ []
+
+[7] (./20.aux) ) 
+Here is how much of TeX's memory you used:
+ 2618 strings out of 494945
+ 41912 string characters out of 6181032
+ 96839 words of memory out of 5000000
+ 5901 multiletter control sequences out of 15000+600000
+ 10544 words of font info for 37 fonts, out of 8000000 for 9000
+ 14 hyphenation exceptions out of 8191
+ 39i,8n,39p,867b,211s stack positions out of 5000i,500n,10000p,200000b,80000s
+</usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/c
+mbx10.pfb></usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmbx12.
+pfb></usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmr10.pfb></u
+sr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmr12.pfb></usr/shar
+e/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmr6.pfb></usr/share/texliv
+e/texmf-dist/fonts/type1/public/amsfonts/cm/cmr8.pfb></usr/share/texlive/texmf-
+dist/fonts/type1/public/amsfonts/cm/cmr9.pfb></usr/share/texlive/texmf-dist/fon
+ts/type1/public/amsfonts/cm/cmsy10.pfb></usr/share/texlive/texmf-dist/fonts/typ
+e1/public/amsfonts/cm/cmti10.pfb></usr/share/texlive/texmf-dist/fonts/type1/pub
+lic/amsfonts/cm/cmtt10.pfb>
+Output written on 20.pdf (7 pages, 544220 bytes).
+PDF statistics:
+ 71 PDF objects out of 1000 (max. 8388607)
+ 48 compressed objects within 1 object stream
+ 0 named destinations out of 1000 (max. 500000)
+ 16 words of extra memory for PDF output out of 10000 (max. 10000000)
+

Car_Stereo_Replacement/docs/20.tex

@@ -0,0 +1,127 @@
+\documentclass[11pt]{article}
+%Gummi|065|=)
+\title{\textbf{Car Stereo Replacement}}
+\usepackage{graphicx,caption}
+%\author{Steak Electronics}
+\date{02/13/20}
+\begin{document}
+
+\maketitle
+\tableofcontents
+
+\section{Car Stereo Replacement}
+Replacing a car stereo. I could just go to ebay, and buy a used car stereo, but where's the fun in that? Let's DIY a car stereo from a PCB used as a frontplate, a connector for my vehicle, and an audio amplifier. I'll connect in signal from an audio player.
+\\
+
+\includegraphics[scale=0.4]{../pics/DSCN2180.JPG}
+\captionof{figure}{PCB rev 1}
+
+\subsection{Items Included}
+I thought I would include the following:
+\begin{itemize}
+\item Arduino Nano
+\item Voltage and Gnd Breakout
+\item I2C Display
+\item Voltage Readout (of BAT)
+\item Current Readout (being drawn)
+\item Amplifier ``Lvpin LP-838''
+\end{itemize}
+I also wanted to have the connectors that eurorack and synth designers use for mono audio cables, but the cables turned out too expensive. The current readout didn't work initially, and I haven't gotten to fixing it yet.
+\subsubsection{I2C OLED display}
+Just for fun, I bought an I2C oled display and am going to use it to display something.\footnote{It's an Arduino Uno, you can put almost anything on this.} Notes on this:
+Using the adafruit SSD1306 and GFX library (this procedure is well covered in other places), you can load an example sketch and get it running. First thing to change is to remove the Adafruit logo and replace it with my own. Let's do that.
+
+From https://design.goeszen.com/convert-image-for-oled-display.html
+\begin{verbatim}
+I'm on Linux here and found that the readily-available 
+ImageMagick package will do the trick for you without
+ any scripting. And runs on the CLI! Simple as that:
+
+    convert some_image.png some.image.mono
+\end{verbatim}
+That's efficient. But it didn't really work out. Too much work, I don't need it that bad. Have to convert it to something the c compiler can read. I instead, just deleted their logo. Good enough for now.
+\subsubsection{Internal AVR Temperature Sensor}
+
+I setup the code to read from the internal temp sensor on the duino. However there is also this:
+
+https://thecavepearlproject.org/2019/02/25/no-parts-temperature-measurement-with-arduino-pro-mini-to-0-005c-or-better/
+
+This would be something to do for more resolution. The built in sensor is not very good, so this above link would be great. Hack a day also covers it. 
+
+\subsection{Wiring Pinout is wrong on Internet - Cable has labels}
+I looked at the picture I have detailing the pinout of my car connector (Delco Delphi radio wiring diagram.jpg in resources). It's close, but not 100\% correct. I found that the cable itself has small text labels on each wire which explain which everything does. I didn't notice earlier, as I didn't look close enough (and no one mentioned this).
+
+\subsection{Arduino VReg Blowout}
+I had a knock off Arduino Nano, and the vreg blew out. I have some other vregs to replace it. I didn't have this problem with an Uno that I use as a ceiling dome light. Although that one is not left on as long, usually. 
+
+\subsection{Amplifier}
+The amplifier I used is one of the cheapest avialable on ebay. I'm not proud. I'm poor. I had to take it apart, and reseat the amplifier ICs as the tab was not making contact with the chassis for one of them. I also added thermal paste. This amp is underpowered for my car, and may need replacing. It gets a bit hot.
+
+Some other issues with this amplifier are that the output connectors can get pushed back, there is only one output connector option, and it must run on battery power, as a 12V 1A or 2A will not power it. Finally, there is a 6V DC bias on output. No output audio isolation, which means you get car noise.
+
+\subsection{AC Audio Coupling to Remove DC Noise from Auto}
+I had some fun with this one. Many videos on this in the video folder. I started with the speakers being directly fed by the amplifier. This worked, but there was some noise coming through. Cars are noisy, this is not surprising. I would've preferred the amplifier to isolate the outputs, but no luck... At this point, I considered two options to block DC and allow AC. 1) Use a transformer. 2) Use capacitors.\footnote{A third option would've been to use a second set of batteries, but that would be laborious.}
+
+\subsubsection{Ground Isolator}
+I had been given a Ground isolator, which was two small transformers on a pcb intended to pass audio from a car powered signal source into the car speakers. I tried this isolator on the output of the speakers, and while it worked, the volume was lower, and it was impractical. I knew as soon as I heard the volume, that the issue was an impedance matching problem. The transformers were too small. They were intended for signal sources, not amplifier outputs. Onto option \#2.
+\\
+
+\begin{center}
+\includegraphics[scale=0.35]{../pics/DSCN2610.JPG}
+\captionof{figure}{Ground Loop Isolator.}
+\end{center}
+\subsubsection{Capacitor Audio Coupling}
+My initial thoughts here were: ``Let's be careful and use non polarized caps''. I bought some 0.22uf and 0.022uf polyester film capacitors at Electronics Plus, the local radioshack replacement, and tried them. No sound. After adjusting the connectors on the amp (which were admittedly loose - it's easy to push them back on the amplifier if you are not careful) I found that the capacitors didn't work. One problem was evident in the oscope. I only used one capacitor on the + output of the speaker amp, but the Amp biases the signal 6 volts. So I needed two. After that was resolved, the signal came through on the output of the capacitor, as viewed on the scope, however there was no sound output. I tried the safe way. It's time to break some rules. 
+
+I grabbed some 1uf (electrolytic polarized) caps I had, and tried these. Again, no sound. Not giving up, I grabbed some 1000uf 'lytics, and tried once more. Now it worked.
+
+\subsubsection{Impedance / ESR of capacitors failing to pass enough power of signal}
+Capacitors are rated for impedance. Some data sheets also call this ESR, it appears after a quick look. It's either in there as impedance or ESR. It's not initially an issue if you are using the capacitor as a DC reservoir, but if you use it in an AC coupling situation then things get interesting. A high impedance, or ESR will block what a low one won't. In this example, it's as simple as the Amplfier either being able to power a speaker or not. Higher capacity caps will have lower impedance. See the picture. Other brands put impedance in a graph, or just call it impedance. 
+
+\includegraphics[scale=0.5]{../pics/esr_impedance_capacitance.png}
+\captionof{figure}{Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.}
+
+\subsubsection{Wikipedia on Impedance}
+
+\emph{In general, a capacitor is seen as a storage component for electric energy. But this is only one capacitor function. A capacitor can also act as an AC resistor. Especially aluminum electrolytic capacitors are used in many applications as a decoupling capacitors to filter or bypass undesired biased AC frequencies to the ground or for capacitive coupling of audio AC signals. Then the dielectric is used only for blocking DC. For such applications the AC resistance, the impedance is as important as the capacitance value. }
+\begin{verbatim} https://en.wikipedia.org/w/index.php\title=Aluminum_electrolytic
+_capacitor&oldid=940281525
+\end{verbatim}
+Essentially, what I learned today.
+
+\subsection{DIY Amp}
+I was flipping through Practical Electronics for Inventors\cite{Scherz}(page 959), when I came across an audio amplifier. He also gives one at the chapter on Semiconductors (pg. 467), although the former is more detailed. With a reasonably simple schematic available, and a high likelihood of it working, I say why not: let's build it up.
+
+I've noticed that the ``Lvpin LP-838'' amplifier I'm using is underpowered for my two front speakers \footnote{Although it seems it would work for one channel, so two of them might be enough. It's rated for 20W, so that is about 15-20W per channel req'd. It works at 20W for both, just that it heats up too much. Multiple ebay sellers have it misquoted at 200W. Just an extra 0, no biggie. Based on all this, it appears each channel of my car speaker needs about 15 watts to be on the safe side. The example schematic is 16 watts. Two should suffice.}, so I will make two of the provided 16 watt amps.
+
+\subsubsection{LM383 is Obsolete}
+That explains why I haven't heard of it. The chip is obsolete. Some sell it on ebay for about \$5 each.
+
+As a different route, could I use some other power amplifier op amp, with the same pinout? Hm... Aha, the LM1875 has the same pinout. Let's use that.\footnote{How did I find this? I searched Digikey for the LM383 sold by rochester, noted it was it the category of Linear - Amplifiers - Audio, chose that, then searched for everything in the same package (TO220-5). Came right up. If this hadn't worked, I would've wanted to try other sites: Farnells, Mouser, etc...}
+
+Will it work with the same schematic? Questionable. May still need to buy a LM383, along with the LM1875, as backup. I might also try a generic power op amp.
+
+Amplfiers are the expensive bom item here.
+
+\subsection{Noise remains with Speaker Isolation}
+I've isolated the speakers from DC with the caps, but noise remains. My next idea was a DC-DC isolated supply. But, I found two threads on eevblog forums\cite{eevblog}, and they recommend a power line filter (they also mention the isolated supply). A filter with a coil and cap (2200uf even low enough) I can quickly build up.
+
+I also want to fix up my portable CRO, I obtained the other day. That needs batteries.
+
+One thing I noticed, is that the amplifier seems to no longer heat up, since the caps were added. Perhaps the DC bias was the cause. I need to confirm this.
+ 
+
+\section{References}
+\begin{thebibliography}{99}
+\bibitem{Scherz}
+  Paul Scherz, and Simon Monk,
+  \emph{Practical Electronics for Inventors}, fourth edition - 2016, McGraw Hill.
+
+\bibitem{eevblog}
+  Various, \emph{https://www.eevblog.com/forum/projects/dreaded-alternator-whine-in-car-stereo/25/} Retrieved 2020-02-21. see also https://www.eevblog.com/forum/beginners/car-engine-signal-interference-with-cell-phone/
+
+\bibitem{partofthe}
+  \emph{https://partofthething.com/thoughts/building-a-low-pass-filter-to-remove-alternator-whine-in-my-car/}. Picture guide and showing basic build in project box. Eevblog users mention you may be able to use the secondary of a transformer, to avoid building the coil.
+  \end{thebibliography}
+
+\end{document}

Car_Stereo_Replacement/docs/20.tex~

@@ -0,0 +1,126 @@
+\documentclass[11pt]{article}
+%Gummi|065|=)
+\title{\textbf{Car Stereo Replacement}}
+\usepackage{graphicx,caption}
+%\author{Steak Electronics}
+\date{02/13/20}
+\begin{document}
+
+\maketitle
+
+\section{Car Stereo Replacement}
+Replacing a car stereo. I could just go to ebay, and buy a used car stereo, but where's the fun in that? Let's DIY a car stereo from a PCB used as a frontplate, a connector for my vehicle, and an audio amplifier. I'll connect in signal from an audio player.
+\\
+
+\includegraphics[scale=0.4]{../pics/DSCN2180.JPG}
+\captionof{figure}{PCB rev 1}
+
+\subsection{Items Included}
+I thought I would include the following:
+\begin{itemize}
+\item Arduino Nano
+\item Voltage and Gnd Breakout
+\item I2C Display
+\item Voltage Readout (of BAT)
+\item Current Readout (being drawn)
+\item Amplifier ``Lvpin LP-838''
+\end{itemize}
+I also wanted to have the connectors that eurorack and synth designers use for mono audio cables, but the cables turned out too expensive. The current readout didn't work initially, and I haven't gotten to fixing it yet.
+\subsubsection{I2C OLED display}
+Just for fun, I bought an I2C oled display and am going to use it to display something.\footnote{It's an Arduino Uno, you can put almost anything on this.} Notes on this:
+Using the adafruit SSD1306 and GFX library (this procedure is well covered in other places), you can load an example sketch and get it running. First thing to change is to remove the Adafruit logo and replace it with my own. Let's do that.
+
+From https://design.goeszen.com/convert-image-for-oled-display.html
+\begin{verbatim}
+I'm on Linux here and found that the readily-available 
+ImageMagick package will do the trick for you without
+ any scripting. And runs on the CLI! Simple as that:
+
+    convert some_image.png some.image.mono
+\end{verbatim}
+That's efficient. But it didn't really work out. Too much work, I don't need it that bad. Have to convert it to something the c compiler can read. I instead, just deleted their logo. Good enough for now.
+\subsubsection{Internal AVR Temperature Sensor}
+
+I setup the code to read from the internal temp sensor on the duino. However there is also this:
+
+https://thecavepearlproject.org/2019/02/25/no-parts-temperature-measurement-with-arduino-pro-mini-to-0-005c-or-better/
+
+This would be something to do for more resolution. The built in sensor is not very good, so this above link would be great. Hack a day also covers it. 
+
+\subsection{Wiring Pinout is wrong on Internet - Cable has labels}
+I looked at the picture I have detailing the pinout of my car connector (Delco Delphi radio wiring diagram.jpg in resources). It's close, but not 100\% correct. I found that the cable itself has small text labels on each wire which explain which everything does. I didn't notice earlier, as I didn't look close enough (and no one mentioned this).
+
+\subsection{Arduino VReg Blowout}
+I had a knock off Arduino Nano, and the vreg blew out. I have some other vregs to replace it. I didn't have this problem with an Uno that I use as a ceiling dome light. Although that one is not left on as long, usually. 
+
+\subsection{Amplifier}
+The amplifier I used is one of the cheapest avialable on ebay. I'm not proud. I'm poor. I had to take it apart, and reseat the amplifier ICs as the tab was not making contact with the chassis for one of them. I also added thermal paste. This amp is underpowered for my car, and may need replacing. It gets a bit hot.
+
+Some other issues with this amplifier are that the output connectors can get pushed back, there is only one output connector option, and it must run on battery power, as a 12V 1A or 2A will not power it. Finally, there is a 6V DC bias on output. No output audio isolation, which means you get car noise.
+
+\subsection{AC Audio Coupling to Remove DC Noise from Auto}
+I had some fun with this one. Many videos on this in the video folder. I started with the speakers being directly fed by the amplifier. This worked, but there was some noise coming through. Cars are noisy, this is not surprising. I would've preferred the amplifier to isolate the outputs, but no luck... At this point, I considered two options to block DC and allow AC. 1) Use a transformer. 2) Use capacitors.\footnote{A third option would've been to use a second set of batteries, but that would be laborious.}
+
+\subsubsection{Ground Isolator}
+I had been given a Ground isolator, which was two small transformers on a pcb intended to pass audio from a car powered signal source into the car speakers. I tried this isolator on the output of the speakers, and while it worked, the volume was lower, and it was impractical. I knew as soon as I heard the volume, that the issue was an impedance matching problem. The transformers were too small. They were intended for signal sources, not amplifier outputs. Onto option \#2.
+\\
+
+\begin{center}
+\includegraphics[scale=0.35]{../pics/DSCN2610.JPG}
+\captionof{figure}{Ground Loop Isolator.}
+\end{center}
+\subsubsection{Capacitor Audio Coupling}
+My initial thoughts here were: ``Let's be careful and use non polarized caps''. I bought some 0.22uf and 0.022uf polyester film capacitors at Electronics Plus, the local radioshack replacement, and tried them. No sound. After adjusting the connectors on the amp (which were admittedly loose - it's easy to push them back on the amplifier if you are not careful) I found that the capacitors didn't work. One problem was evident in the oscope. I only used one capacitor on the + output of the speaker amp, but the Amp biases the signal 6 volts. So I needed two. After that was resolved, the signal came through on the output of the capacitor, as viewed on the scope, however there was no sound output. I tried the safe way. It's time to break some rules. 
+
+I grabbed some 1uf (electrolytic polarized) caps I had, and tried these. Again, no sound. Not giving up, I grabbed some 1000uf 'lytics, and tried once more. Now it worked.
+
+\subsubsection{Impedance / ESR of capacitors failing to pass enough power of signal}
+Capacitors are rated for impedance. Some data sheets also call this ESR, it appears after a quick look. It's either in there as impedance or ESR. It's not initially an issue if you are using the capacitor as a DC reservoir, but if you use it in an AC coupling situation then things get interesting. A high impedance, or ESR will block what a low one won't. In this example, it's as simple as the Amplfier either being able to power a speaker or not. Higher capacity caps will have lower impedance. See the picture. Other brands put impedance in a graph, or just call it impedance. 
+
+\includegraphics[scale=0.5]{../pics/esr_impedance_capacitance.png}
+\captionof{figure}{Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.}
+
+\subsubsection{Wikipedia on Impedance}
+
+\emph{In general, a capacitor is seen as a storage component for electric energy. But this is only one capacitor function. A capacitor can also act as an AC resistor. Especially aluminum electrolytic capacitors are used in many applications as a decoupling capacitors to filter or bypass undesired biased AC frequencies to the ground or for capacitive coupling of audio AC signals. Then the dielectric is used only for blocking DC. For such applications the AC resistance, the impedance is as important as the capacitance value. }
+\begin{verbatim} https://en.wikipedia.org/w/index.php\title=Aluminum_electrolytic
+_capacitor&oldid=940281525
+\end{verbatim}
+Essentially, what I learned today.
+
+\subsection{DIY Amp}
+I was flipping through Practical Electronics for Inventors\cite{Scherz}(page 959), when I came across an audio amplifier. He also gives one at the chapter on Semiconductors (pg. 467), although the former is more detailed. With a reasonably simple schematic available, and a high likelihood of it working, I say why not: let's build it up.
+
+I've noticed that the ``Lvpin LP-838'' amplifier I'm using is underpowered for my two front speakers \footnote{Although it seems it would work for one channel, so two of them might be enough. It's rated for 20W, so that is about 15-20W per channel req'd. It works at 20W for both, just that it heats up too much. Multiple ebay sellers have it misquoted at 200W. Just an extra 0, no biggie. Based on all this, it appears each channel of my car speaker needs about 15 watts to be on the safe side. The example schematic is 16 watts. Two should suffice.}, so I will make two of the provided 16 watt amps.
+
+\subsubsection{LM383 is Obsolete}
+That explains why I haven't heard of it. The chip is obsolete. Some sell it on ebay for about \$5 each.
+
+As a different route, could I use some other power amplifier op amp, with the same pinout? Hm... Aha, the LM1875 has the same pinout. Let's use that.\footnote{How did I find this? I searched Digikey for the LM383 sold by rochester, noted it was it the category of Linear - Amplifiers - Audio, chose that, then searched for everything in the same package (TO220-5). Came right up. If this hadn't worked, I would've wanted to try other sites: Farnells, Mouser, etc...}
+
+Will it work with the same schematic? Questionable. May still need to buy a LM383, along with the LM1875, as backup. I might also try a generic power op amp.
+
+Amplfiers are the expensive bom item here.
+
+\subsection{Noise remains with Speaker Isolation}
+I've isolated the speakers from DC with the caps, but noise remains. My next idea was a DC-DC isolated supply. But, I found two threads on eevblog forums\cite{eevblog}, and they recommend a power line filter (they also mention the isolated supply). A filter with a coil and cap (2200uf even low enough) I can quickly build up.
+
+I also want to fix up my portable CRO, I obtained the other day. That needs batteries.
+
+One thing I noticed, is that the amplifier seems to no longer heat up, since the caps were added. Perhaps the DC bias was the cause. I need to confirm this.
+ 
+
+\section{References}
+\begin{thebibliography}{99}
+\bibitem{Scherz}
+  Paul Scherz, and Simon Monk,
+  \emph{Practical Electronics for Inventors}, fourth edition - 2016, McGraw Hill.
+
+\bibitem{eevblog}
+  Various, \emph{https://www.eevblog.com/forum/projects/dreaded-alternator-whine-in-car-stereo/25/} Retrieved 2020-02-21. see also https://www.eevblog.com/forum/beginners/car-engine-signal-interference-with-cell-phone/
+
+\bibitem{partofthe}
+  \emph{https://partofthething.com/thoughts/building-a-low-pass-filter-to-remove-alternator-whine-in-my-car/}. Picture guide and showing basic build in project box. Eevblog users mention you may be able to use the secondary of a transformer, to avoid building the coil.
+  \end{thebibliography}
+
+\end{document}

Car_Stereo_Replacement/docs/20.toc

@@ -0,0 +1,16 @@
+\contentsline {section}{\numberline {1}Car Stereo Replacement}{1}
+\contentsline {subsection}{\numberline {1.1}Items Included}{2}
+\contentsline {subsubsection}{\numberline {1.1.1}I2C OLED display}{2}
+\contentsline {subsubsection}{\numberline {1.1.2}Internal AVR Temperature Sensor}{3}
+\contentsline {subsection}{\numberline {1.2}Wiring Pinout is wrong on Internet - Cable has labels}{3}
+\contentsline {subsection}{\numberline {1.3}Arduino VReg Blowout}{3}
+\contentsline {subsection}{\numberline {1.4}Amplifier}{3}
+\contentsline {subsection}{\numberline {1.5}AC Audio Coupling to Remove DC Noise from Auto}{3}
+\contentsline {subsubsection}{\numberline {1.5.1}Ground Isolator}{4}
+\contentsline {subsubsection}{\numberline {1.5.2}Capacitor Audio Coupling}{4}
+\contentsline {subsubsection}{\numberline {1.5.3}Impedance / ESR of capacitors failing to pass enough power of signal}{5}
+\contentsline {subsubsection}{\numberline {1.5.4}Wikipedia on Impedance}{6}
+\contentsline {subsection}{\numberline {1.6}DIY Amp}{6}
+\contentsline {subsubsection}{\numberline {1.6.1}LM383 is Obsolete}{6}
+\contentsline {subsection}{\numberline {1.7}Noise remains with Speaker Isolation}{7}
+\contentsline {section}{\numberline {2}References}{7}

Car_Stereo_Replacement/docs/21.aux

@@ -0,0 +1,25 @@
+\relax 
+\@writefile{toc}{\contentsline {section}{\numberline {1}Car Stereo Replacement}{1}}
+\@writefile{lof}{\contentsline {figure}{\numberline {1}{\ignorespaces PCB rev 1\relax }}{2}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.1}Items Included}{2}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.1.1}I2C OLED display}{3}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.1.2}Internal AVR Temperature Sensor}{3}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.2}Wiring Pinout is wrong on Internet - Cable has labels}{3}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.3}Arduino VReg Blowout}{3}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.4}Amplifier}{4}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.5}AC Audio Coupling to Remove DC Noise from Auto}{4}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.5.1}Ground Isolator}{4}}
+\@writefile{lof}{\contentsline {figure}{\numberline {2}{\ignorespaces Ground Loop Isolator.\relax }}{5}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.5.2}Capacitor Audio Coupling}{5}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.5.3}Impedance / ESR of capacitors failing to pass enough power of signal}{5}}
+\citation{Scherz}
+\@writefile{lof}{\contentsline {figure}{\numberline {3}{\ignorespaces Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.\relax }}{6}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.5.4}Wikipedia on Impedance}{6}}
+\citation{eevblog}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.6}DIY Amp}{7}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.6.1}LM383 is Obsolete}{7}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.7}Noise remains with Speaker Isolation}{7}}
+\bibcite{Scherz}{1}
+\bibcite{eevblog}{2}
+\bibcite{partofthe}{3}
+\@writefile{toc}{\contentsline {section}{\numberline {2}References}{8}}

Car_Stereo_Replacement/docs/21.log

@@ -0,0 +1,283 @@
+This is pdfTeX, Version 3.14159265-2.6-1.40.17 (TeX Live 2016/Debian) (preloaded format=pdflatex 2019.8.17)  5 MAR 2020 23:57
+entering extended mode
+ restricted \write18 enabled.
+ %&-line parsing enabled.
+**/home/layoutdev/Desktop/code/documentation_general/Electronics_Projects_2019/
+Car_Stereo_Replacement/docs/21.tex
+
+(/home/layoutdev/Desktop/code/documentation_general/Electronics_Projects_2019/C
+ar_Stereo_Replacement/docs/21.tex
+LaTeX2e <2017/01/01> patch level 3
+Babel <3.9r> and hyphenation patterns for 3 language(s) loaded.
+(/usr/share/texlive/texmf-dist/tex/latex/base/article.cls
+Document Class: article 2014/09/29 v1.4h Standard LaTeX document class
+(/usr/share/texlive/texmf-dist/tex/latex/base/size11.clo
+File: size11.clo 2014/09/29 v1.4h Standard LaTeX file (size option)
+)
+\c@part=\count79
+\c@section=\count80
+\c@subsection=\count81
+\c@subsubsection=\count82
+\c@paragraph=\count83
+\c@subparagraph=\count84
+\c@figure=\count85
+\c@table=\count86
+\abovecaptionskip=\skip41
+\belowcaptionskip=\skip42
+\bibindent=\dimen102
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/graphicx.sty
+Package: graphicx 2014/10/28 v1.0g Enhanced LaTeX Graphics (DPC,SPQR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/keyval.sty
+Package: keyval 2014/10/28 v1.15 key=value parser (DPC)
+\KV@toks@=\toks14
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/graphics.sty
+Package: graphics 2016/10/09 v1.0u Standard LaTeX Graphics (DPC,SPQR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/trig.sty
+Package: trig 2016/01/03 v1.10 sin cos tan (DPC)
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics-cfg/graphics.cfg
+File: graphics.cfg 2016/06/04 v1.11 sample graphics configuration
+)
+Package graphics Info: Driver file: pdftex.def on input line 99.
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics-def/pdftex.def
+File: pdftex.def 2017/01/12 v0.06k Graphics/color for pdfTeX
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/infwarerr.sty
+Package: infwarerr 2016/05/16 v1.4 Providing info/warning/error messages (HO)
+)
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ltxcmds.sty
+Package: ltxcmds 2016/05/16 v1.23 LaTeX kernel commands for general use (HO)
+)
+\Gread@gobject=\count87
+))
+\Gin@req@height=\dimen103
+\Gin@req@width=\dimen104
+)
+(/usr/share/texlive/texmf-dist/tex/latex/caption/caption.sty
+Package: caption 2016/02/21 v3.3-144 Customizing captions (AR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/caption/caption3.sty
+Package: caption3 2016/05/22 v1.7-166 caption3 kernel (AR)
+Package caption3 Info: TeX engine: e-TeX on input line 67.
+\captionmargin=\dimen105
+\captionmargin@=\dimen106
+\captionwidth=\dimen107
+\caption@tempdima=\dimen108
+\caption@indent=\dimen109
+\caption@parindent=\dimen110
+\caption@hangindent=\dimen111
+)
+\c@ContinuedFloat=\count88
+) (./21.aux)
+\openout1 = `21.aux'.
+
+LaTeX Font Info:    Checking defaults for OML/cmm/m/it on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for T1/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OT1/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OMS/cmsy/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OMX/cmex/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for U/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+
+(/usr/share/texlive/texmf-dist/tex/context/base/mkii/supp-pdf.mkii
+[Loading MPS to PDF converter (version 2006.09.02).]
+\scratchcounter=\count89
+\scratchdimen=\dimen112
+\scratchbox=\box26
+\nofMPsegments=\count90
+\nofMParguments=\count91
+\everyMPshowfont=\toks15
+\MPscratchCnt=\count92
+\MPscratchDim=\dimen113
+\MPnumerator=\count93
+\makeMPintoPDFobject=\count94
+\everyMPtoPDFconversion=\toks16
+) (/usr/share/texlive/texmf-dist/tex/generic/oberdiek/pdftexcmds.sty
+Package: pdftexcmds 2016/05/21 v0.22 Utility functions of pdfTeX for LuaTeX (HO
+)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ifluatex.sty
+Package: ifluatex 2016/05/16 v1.4 Provides the ifluatex switch (HO)
+Package ifluatex Info: LuaTeX not detected.
+)
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ifpdf.sty
+Package: ifpdf 2016/05/14 v3.1 Provides the ifpdf switch
+)
+Package pdftexcmds Info: LuaTeX not detected.
+Package pdftexcmds Info: \pdf@primitive is available.
+Package pdftexcmds Info: \pdf@ifprimitive is available.
+Package pdftexcmds Info: \pdfdraftmode found.
+)
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/epstopdf-base.sty
+Package: epstopdf-base 2016/05/15 v2.6 Base part for package epstopdf
+
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/grfext.sty
+Package: grfext 2016/05/16 v1.2 Manage graphics extensions (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/kvdefinekeys.sty
+Package: kvdefinekeys 2016/05/16 v1.4 Define keys (HO)
+))
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/kvoptions.sty
+Package: kvoptions 2016/05/16 v3.12 Key value format for package options (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/kvsetkeys.sty
+Package: kvsetkeys 2016/05/16 v1.17 Key value parser (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/etexcmds.sty
+Package: etexcmds 2016/05/16 v1.6 Avoid name clashes with e-TeX commands (HO)
+Package etexcmds Info: Could not find \expanded.
+(etexcmds)             That can mean that you are not using pdfTeX 1.50 or
+(etexcmds)             that some package has redefined \expanded.
+(etexcmds)             In the latter case, load this package earlier.
+)))
+Package epstopdf-base Info: Redefining graphics rule for `.eps' on input line 4
+38.
+Package grfext Info: Graphics extension search list:
+(grfext)             [.png,.pdf,.jpg,.mps,.jpeg,.jbig2,.jb2,.PNG,.PDF,.JPG,.JPE
+G,.JBIG2,.JB2,.eps]
+(grfext)             \AppendGraphicsExtensions on input line 456.
+
+(/usr/share/texlive/texmf-dist/tex/latex/latexconfig/epstopdf-sys.cfg
+File: epstopdf-sys.cfg 2010/07/13 v1.3 Configuration of (r)epstopdf for TeX Liv
+e
+))
+Package caption Info: Begin \AtBeginDocument code.
+Package caption Info: End \AtBeginDocument code.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <12> on input line 9.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <8> on input line 9.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <6> on input line 9.
+
+
+LaTeX Warning: No \author given.
+
+(./21.toc
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <10.95> on input line 2.
+)
+\tf@toc=\write3
+\openout3 = `21.toc'.
+
+
+Underfull \hbox (badness 10000) in paragraph at lines 13--15
+
+ []
+
+<../pics/DSCN2180.JPG, id=1, 803.0pt x 602.25pt>
+File: ../pics/DSCN2180.JPG Graphic file (type jpg)
+ <use ../pics/DSCN2180.JPG>
+Package pdftex.def Info: ../pics/DSCN2180.JPG used on input line 16.
+(pdftex.def)             Requested size: 321.1943pt x 240.89572pt.
+
+
+Package caption Warning: \captionsetup{type*=...} or \captionof
+(caption)                outside box or environment on input line 17.
+See the caption package documentation for explanation.
+
+[1
+
+{/var/lib/texmf/fonts/map/pdftex/updmap/pdftex.map}]
+LaTeX Font Info:    Try loading font information for OMS+cmr on input line 22.
+
+(/usr/share/texlive/texmf-dist/tex/latex/base/omscmr.fd
+File: omscmr.fd 2014/09/29 v2.5h Standard LaTeX font definitions
+)
+LaTeX Font Info:    Font shape `OMS/cmr/m/n' in size <10.95> not available
+(Font)              Font shape `OMS/cmsy/m/n' tried instead on input line 22.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <9> on input line 31.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <5> on input line 31.
+ [2 <../pics/DSCN2180.JPG>]
+Underfull \hbox (badness 10000) in paragraph at lines 47--48
+[]\OT1/cmr/m/n/10.95 https://thecavepearlproject.org/2019/02/25/no-parts-temper
+ature-
+ []
+
+[3]
+Underfull \hbox (badness 10000) in paragraph at lines 66--68
+
+ []
+
+<../pics/DSCN2610.JPG, id=22, 803.0pt x 602.25pt>
+File: ../pics/DSCN2610.JPG Graphic file (type jpg)
+ <use ../pics/DSCN2610.JPG>
+Package pdftex.def Info: ../pics/DSCN2610.JPG used on input line 70.
+(pdftex.def)             Requested size: 281.05421pt x 210.79065pt.
+
+[4] [5 <../pics/DSCN2610.JPG>]
+<../pics/esr_impedance_capacitance.png, id=29, 697.10437pt x 421.69917pt>
+File: ../pics/esr_impedance_capacitance.png Graphic file (type png)
+
+<use ../pics/esr_impedance_capacitance.png>
+Package pdftex.def Info: ../pics/esr_impedance_capacitance.png used on input li
+ne 81.
+(pdftex.def)             Requested size: 348.55133pt x 210.84906pt.
+
+Overfull \hbox (13.6647pt too wide) in paragraph at lines 89--89
+[] \OT1/cmtt/m/n/10.95 https://en.wikipedia.org/w/index.php\title=Aluminum_elec
+trolytic 
+ []
+
+[6 <../pics/esr_impedance_capacitance.png (PNG copy)>] [7]
+Underfull \hbox (badness 10000) in paragraph at lines 121--122
+[]\OT1/cmr/m/n/10.95 Various, \OT1/cmr/m/it/10.95 https://www.eevblog.com/forum
+/projects/dreaded-
+ []
+
+
+Underfull \hbox (badness 10000) in paragraph at lines 121--122
+\OT1/cmr/m/it/10.95 alternator-whine-in-car-stereo/25/ \OT1/cmr/m/n/10.95 Re-tr
+ieved 2020-02-21. see
+ []
+
+
+Underfull \hbox (badness 10000) in paragraph at lines 121--122
+\OT1/cmr/m/n/10.95 also https://www.eevblog.com/forum/beginners/car-engine-sign
+al-
+ []
+
+
+Underfull \hbox (badness 10000) in paragraph at lines 124--125
+[]\OT1/cmr/m/it/10.95 https://partofthething.com/thoughts/building-a-low-pass-f
+ilter-to-
+ []
+
+[8] (./21.aux) ) 
+Here is how much of TeX's memory you used:
+ 2620 strings out of 494945
+ 41926 string characters out of 6181032
+ 96839 words of memory out of 5000000
+ 5901 multiletter control sequences out of 15000+600000
+ 10544 words of font info for 37 fonts, out of 8000000 for 9000
+ 14 hyphenation exceptions out of 8191
+ 39i,8n,39p,867b,265s stack positions out of 5000i,500n,10000p,200000b,80000s
+</usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/c
+mbx10.pfb></usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmbx12.
+pfb></usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmr10.pfb></u
+sr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmr12.pfb></usr/shar
+e/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmr6.pfb></usr/share/texliv
+e/texmf-dist/fonts/type1/public/amsfonts/cm/cmr8.pfb></usr/share/texlive/texmf-
+dist/fonts/type1/public/amsfonts/cm/cmr9.pfb></usr/share/texlive/texmf-dist/fon
+ts/type1/public/amsfonts/cm/cmsy10.pfb></usr/share/texlive/texmf-dist/fonts/typ
+e1/public/amsfonts/cm/cmti10.pfb></usr/share/texlive/texmf-dist/fonts/type1/pub
+lic/amsfonts/cm/cmtt10.pfb>
+Output written on 21.pdf (8 pages, 545136 bytes).
+PDF statistics:
+ 74 PDF objects out of 1000 (max. 8388607)
+ 50 compressed objects within 1 object stream
+ 0 named destinations out of 1000 (max. 500000)
+ 16 words of extra memory for PDF output out of 10000 (max. 10000000)
+

Car_Stereo_Replacement/docs/21.tex

@@ -0,0 +1,127 @@
+\documentclass[11pt]{article}
+%Gummi|065|=)
+\title{\textbf{Car Stereo Replacement}}
+\usepackage{graphicx,caption}
+%\author{Steak Electronics}
+\date{02/13/20}
+\begin{document}
+
+\maketitle
+\tableofcontents
+
+\section{Car Stereo Replacement}
+Replacing a car stereo. I could just go to ebay, and buy a used car stereo, but where's the fun in that? Let's DIY a car stereo from a PCB used as a frontplate, a connector for my vehicle, and an audio amplifier. I'll connect in signal from an audio player.
+\\
+
+\includegraphics[scale=0.4]{../pics/DSCN2180.JPG}
+\captionof{figure}{PCB rev 1}
+
+\subsection{Items Included}
+I thought I would include the following:
+\begin{itemize}
+\item Arduino Nano
+\item Voltage and Gnd Breakout
+\item I2C Display
+\item Voltage Readout (of BAT)
+\item Current Readout (being drawn)
+\item Amplifier ``Lvpin LP-838''
+\end{itemize}
+I also wanted to have the connectors that eurorack and synth designers use for mono audio cables, but the cables turned out too expensive. The current readout didn't work initially, and I haven't gotten to fixing it yet.
+\subsubsection{I2C OLED display}
+Just for fun, I bought an I2C oled display and am going to use it to display something.\footnote{It's an Arduino Uno, you can put almost anything on this.} Notes on this:
+Using the adafruit SSD1306 and GFX library (this procedure is well covered in other places), you can load an example sketch and get it running. First thing to change is to remove the Adafruit logo and replace it with my own. Let's do that.
+
+From https://design.goeszen.com/convert-image-for-oled-display.html
+\begin{verbatim}
+I'm on Linux here and found that the readily-available 
+ImageMagick package will do the trick for you without
+ any scripting. And runs on the CLI! Simple as that:
+
+    convert some_image.png some.image.mono
+\end{verbatim}
+That's efficient. But it didn't really work out. Too much work, I don't need it that bad. Have to convert it to something the c compiler can read. I instead, just deleted their logo. Good enough for now.
+\subsubsection{Internal AVR Temperature Sensor}
+
+I setup the code to read from the internal temp sensor on the duino. However there is also this:
+
+https://thecavepearlproject.org/2019/02/25/no-parts-temperature-measurement-with-arduino-pro-mini-to-0-005c-or-better/
+
+This would be something to do for more resolution. The built in sensor is not very good, so this above link would be great. Hack a day also covers it. 
+
+\subsection{Wiring Pinout is wrong on Internet - Cable has labels}
+I looked at the picture I have detailing the pinout of my car connector (Delco Delphi radio wiring diagram.jpg in resources). It's close, but not 100\% correct. I found that the cable itself has small text labels on each wire which explain which everything does. I didn't notice earlier, as I didn't look close enough (and no one mentioned this).
+
+\subsection{Arduino VReg Blowout}
+I had a knock off Arduino Nano, and the vreg blew out. I have some other vregs to replace it. I didn't have this problem with an Uno that I use as a ceiling dome light. Although that one is not left on as long, usually. 
+
+\subsection{Amplifier}
+The amplifier I used is one of the cheapest avialable on ebay. I'm not proud. I'm poor. I had to take it apart, and reseat the amplifier ICs as the tab was not making contact with the chassis for one of them. I also added thermal paste. This amp is underpowered for my car, and may need replacing. It gets a bit hot.
+
+Some other issues with this amplifier are that the output connectors can get pushed back, there is only one output connector option, and it must run on battery power, as a 12V 1A or 2A will not power it. Finally, there is a 6V DC bias on output. No output audio isolation, which means you get car noise.
+
+\subsection{AC Audio Coupling to Remove DC Noise from Auto}
+I had some fun with this one. Many videos on this in the video folder. I started with the speakers being directly fed by the amplifier. This worked, but there was some noise coming through. Cars are noisy, this is not surprising. I would've preferred the amplifier to isolate the outputs, but no luck... At this point, I considered two options to block DC and allow AC. 1) Use a transformer. 2) Use capacitors.\footnote{A third option would've been to use a second set of batteries, but that would be laborious.}
+
+\subsubsection{Ground Isolator}
+I had been given a Ground isolator, which was two small transformers on a pcb intended to pass audio from a car powered signal source into the car speakers. I tried this isolator on the output of the speakers, and while it worked, the volume was lower, and it was impractical. I knew as soon as I heard the volume, that the issue was an impedance matching problem. The transformers were too small. They were intended for signal sources, not amplifier outputs. Onto option \#2.
+\\
+
+\begin{center}
+\includegraphics[scale=0.35]{../pics/DSCN2610.JPG}
+\captionof{figure}{Ground Loop Isolator.}
+\end{center}
+\subsubsection{Capacitor Audio Coupling}
+My initial thoughts here were: ``Let's be careful and use non polarized caps''. I bought some 0.22uf and 0.022uf polyester film capacitors at Electronics Plus, the local radioshack replacement, and tried them. No sound. After adjusting the connectors on the amp (which were admittedly loose - it's easy to push them back on the amplifier if you are not careful) I found that the capacitors didn't work. One problem was evident in the oscope. I only used one capacitor on the + output of the speaker amp, but the Amp biases the signal 6 volts. So I needed two. After that was resolved, the signal came through on the output of the capacitor, as viewed on the scope, however there was no sound output. I tried the safe way. It's time to break some rules. 
+
+I grabbed some 1uf (electrolytic polarized) caps I had, and tried these. Again, no sound. Not giving up, I grabbed some 1000uf 'lytics, and tried once more. Now it worked.
+
+\subsubsection{Impedance / ESR of capacitors failing to pass enough power of signal}
+Capacitors are rated for impedance. Some data sheets also call this ESR, it appears after a quick look. It's either in there as impedance or ESR. It's not initially an issue if you are using the capacitor as a DC reservoir, but if you use it in an AC coupling situation then things get interesting. A high impedance, or ESR will block what a low one won't. In this example, it's as simple as the Amplfier either being able to power a speaker or not. Higher capacity caps will have lower impedance. See the picture. Other brands put impedance in a graph, or just call it impedance. 
+
+\includegraphics[scale=0.5]{../pics/esr_impedance_capacitance.png}
+\captionof{figure}{Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.}
+
+\subsubsection{Wikipedia on Impedance}
+
+\emph{In general, a capacitor is seen as a storage component for electric energy. But this is only one capacitor function. A capacitor can also act as an AC resistor. Especially aluminum electrolytic capacitors are used in many applications as a decoupling capacitors to filter or bypass undesired biased AC frequencies to the ground or for capacitive coupling of audio AC signals. Then the dielectric is used only for blocking DC. For such applications the AC resistance, the impedance is as important as the capacitance value. }
+\begin{verbatim} https://en.wikipedia.org/w/index.php\title=Aluminum_electrolytic
+_capacitor&oldid=940281525
+\end{verbatim}
+Essentially, what I learned today.
+
+\subsection{DIY Amp}
+I was flipping through Practical Electronics for Inventors\cite{Scherz}(page 959), when I came across an audio amplifier. He also gives one at the chapter on Semiconductors (pg. 467), although the former is more detailed. With a reasonably simple schematic available, and a high likelihood of it working, I say why not: let's build it up.
+
+I've noticed that the ``Lvpin LP-838'' amplifier I'm using is underpowered for my two front speakers \footnote{Although it seems it would work for one channel, so two of them might be enough. It's rated for 20W, so that is about 15-20W per channel req'd. It works at 20W for both, just that it heats up too much. Multiple ebay sellers have it misquoted at 200W. Just an extra 0, no biggie. Based on all this, it appears each channel of my car speaker needs about 15 watts to be on the safe side. The example schematic is 16 watts. Two should suffice.}, so I will make two of the provided 16 watt amps.
+
+\subsubsection{LM383 is Obsolete}
+That explains why I haven't heard of it. The chip is obsolete. Some sell it on ebay for about \$5 each.
+
+As a different route, could I use some other power amplifier op amp, with the same pinout? Hm... Aha, the LM1875 has the same pinout. Let's use that.\footnote{How did I find this? I searched Digikey for the LM383 sold by rochester, noted it was it the category of Linear - Amplifiers - Audio, chose that, then searched for everything in the same package (TO220-5). Came right up. If this hadn't worked, I would've wanted to try other sites: Farnells, Mouser, etc...}
+
+Will it work with the same schematic? Questionable. May still need to buy a LM383, along with the LM1875, as backup. I might also try a generic power op amp.
+
+Amplfiers are the expensive bom item here.
+
+\subsection{Noise remains with Speaker Isolation}
+I've isolated the speakers from DC with the caps, but noise remains. My next idea was a DC-DC isolated supply. But, I found two threads on eevblog forums\cite{eevblog}, and they recommend a power line filter (they also mention the isolated supply). A filter with a coil and cap (2200uf even low enough) I can quickly build up.
+
+I also want to fix up my portable CRO, I obtained the other day. That needs batteries.
+
+One thing I noticed, is that the amplifier seems to no longer heat up, since the caps were added. Perhaps the DC bias was the cause. I need to confirm this.
+ 
+
+\section{References}
+\begin{thebibliography}{99}
+\bibitem{Scherz}
+  Paul Scherz, and Simon Monk,
+  \emph{Practical Electronics for Inventors}, fourth edition - 2016, McGraw Hill.
+
+\bibitem{eevblog}
+  Various, \emph{https://www.eevblog.com/forum/projects/dreaded-alternator-whine-in-car-stereo/25/} Retrieved 2020-02-21. see also https://www.eevblog.com/forum/beginners/car-engine-signal-interference-with-cell-phone/
+
+\bibitem{partofthe}
+  \emph{https://partofthething.com/thoughts/building-a-low-pass-filter-to-remove-alternator-whine-in-my-car/}. Picture guide and showing basic build in project box. Eevblog users mention you may be able to use the secondary of a transformer, to avoid building the coil.
+  \end{thebibliography}
+
+\end{document}

Car_Stereo_Replacement/docs/21.toc

@@ -0,0 +1,16 @@
+\contentsline {section}{\numberline {1}Car Stereo Replacement}{1}
+\contentsline {subsection}{\numberline {1.1}Items Included}{2}
+\contentsline {subsubsection}{\numberline {1.1.1}I2C OLED display}{3}
+\contentsline {subsubsection}{\numberline {1.1.2}Internal AVR Temperature Sensor}{3}
+\contentsline {subsection}{\numberline {1.2}Wiring Pinout is wrong on Internet - Cable has labels}{3}
+\contentsline {subsection}{\numberline {1.3}Arduino VReg Blowout}{3}
+\contentsline {subsection}{\numberline {1.4}Amplifier}{4}
+\contentsline {subsection}{\numberline {1.5}AC Audio Coupling to Remove DC Noise from Auto}{4}
+\contentsline {subsubsection}{\numberline {1.5.1}Ground Isolator}{4}
+\contentsline {subsubsection}{\numberline {1.5.2}Capacitor Audio Coupling}{5}
+\contentsline {subsubsection}{\numberline {1.5.3}Impedance / ESR of capacitors failing to pass enough power of signal}{5}
+\contentsline {subsubsection}{\numberline {1.5.4}Wikipedia on Impedance}{6}
+\contentsline {subsection}{\numberline {1.6}DIY Amp}{7}
+\contentsline {subsubsection}{\numberline {1.6.1}LM383 is Obsolete}{7}
+\contentsline {subsection}{\numberline {1.7}Noise remains with Speaker Isolation}{7}
+\contentsline {section}{\numberline {2}References}{8}

Car_Stereo_Replacement/docs/22.aux

@@ -0,0 +1,25 @@
+\relax 
+\@writefile{toc}{\contentsline {section}{\numberline {1}Car Stereo Replacement}{1}}
+\@writefile{lof}{\contentsline {figure}{\numberline {1}{\ignorespaces PCB rev 1\relax }}{1}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.1}Items Included}{1}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.1.1}I2C OLED display}{2}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.1.2}Internal AVR Temperature Sensor}{2}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.2}Wiring Pinout is wrong on Internet - Cable has labels}{3}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.3}Arduino VReg Blowout}{3}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.4}Amplifier}{3}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.5}AC Audio Coupling to Remove DC Noise from Auto}{3}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.5.1}Ground Isolator}{4}}
+\@writefile{lof}{\contentsline {figure}{\numberline {2}{\ignorespaces Ground Loop Isolator.\relax }}{4}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.5.2}Capacitor Audio Coupling}{4}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.5.3}Impedance / ESR of capacitors failing to pass enough power of signal}{5}}
+\@writefile{lof}{\contentsline {figure}{\numberline {3}{\ignorespaces Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.\relax }}{5}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.5.4}Wikipedia on Impedance}{5}}
+\citation{Scherz}
+\citation{eevblog}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.6}DIY Amp}{6}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.6.1}LM383 is Obsolete}{6}}
+\bibcite{Scherz}{1}
+\bibcite{eevblog}{2}
+\bibcite{partofthe}{3}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.7}Noise remains with Speaker Isolation}{7}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.8}References}{7}}

Car_Stereo_Replacement/docs/22.log

@@ -0,0 +1,277 @@
+This is pdfTeX, Version 3.14159265-2.6-1.40.17 (TeX Live 2016/Debian) (preloaded format=pdflatex 2019.8.17)  10 MAR 2020 02:03
+entering extended mode
+ restricted \write18 enabled.
+ %&-line parsing enabled.
+**/home/layoutdev/Desktop/code/documentation_general/Electronics_Projects_2019/
+Car_Stereo_Replacement/docs/22.tex
+
+(/home/layoutdev/Desktop/code/documentation_general/Electronics_Projects_2019/C
+ar_Stereo_Replacement/docs/22.tex
+LaTeX2e <2017/01/01> patch level 3
+Babel <3.9r> and hyphenation patterns for 3 language(s) loaded.
+(/usr/share/texlive/texmf-dist/tex/latex/base/article.cls
+Document Class: article 2014/09/29 v1.4h Standard LaTeX document class
+(/usr/share/texlive/texmf-dist/tex/latex/base/size11.clo
+File: size11.clo 2014/09/29 v1.4h Standard LaTeX file (size option)
+)
+\c@part=\count79
+\c@section=\count80
+\c@subsection=\count81
+\c@subsubsection=\count82
+\c@paragraph=\count83
+\c@subparagraph=\count84
+\c@figure=\count85
+\c@table=\count86
+\abovecaptionskip=\skip41
+\belowcaptionskip=\skip42
+\bibindent=\dimen102
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/graphicx.sty
+Package: graphicx 2014/10/28 v1.0g Enhanced LaTeX Graphics (DPC,SPQR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/keyval.sty
+Package: keyval 2014/10/28 v1.15 key=value parser (DPC)
+\KV@toks@=\toks14
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/graphics.sty
+Package: graphics 2016/10/09 v1.0u Standard LaTeX Graphics (DPC,SPQR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/trig.sty
+Package: trig 2016/01/03 v1.10 sin cos tan (DPC)
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics-cfg/graphics.cfg
+File: graphics.cfg 2016/06/04 v1.11 sample graphics configuration
+)
+Package graphics Info: Driver file: pdftex.def on input line 99.
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics-def/pdftex.def
+File: pdftex.def 2017/01/12 v0.06k Graphics/color for pdfTeX
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/infwarerr.sty
+Package: infwarerr 2016/05/16 v1.4 Providing info/warning/error messages (HO)
+)
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ltxcmds.sty
+Package: ltxcmds 2016/05/16 v1.23 LaTeX kernel commands for general use (HO)
+)
+\Gread@gobject=\count87
+))
+\Gin@req@height=\dimen103
+\Gin@req@width=\dimen104
+)
+(/usr/share/texlive/texmf-dist/tex/latex/caption/caption.sty
+Package: caption 2016/02/21 v3.3-144 Customizing captions (AR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/caption/caption3.sty
+Package: caption3 2016/05/22 v1.7-166 caption3 kernel (AR)
+Package caption3 Info: TeX engine: e-TeX on input line 67.
+\captionmargin=\dimen105
+\captionmargin@=\dimen106
+\captionwidth=\dimen107
+\caption@tempdima=\dimen108
+\caption@indent=\dimen109
+\caption@parindent=\dimen110
+\caption@hangindent=\dimen111
+)
+\c@ContinuedFloat=\count88
+) (./22.aux)
+\openout1 = `22.aux'.
+
+LaTeX Font Info:    Checking defaults for OML/cmm/m/it on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for T1/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OT1/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OMS/cmsy/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OMX/cmex/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for U/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+
+(/usr/share/texlive/texmf-dist/tex/context/base/mkii/supp-pdf.mkii
+[Loading MPS to PDF converter (version 2006.09.02).]
+\scratchcounter=\count89
+\scratchdimen=\dimen112
+\scratchbox=\box26
+\nofMPsegments=\count90
+\nofMParguments=\count91
+\everyMPshowfont=\toks15
+\MPscratchCnt=\count92
+\MPscratchDim=\dimen113
+\MPnumerator=\count93
+\makeMPintoPDFobject=\count94
+\everyMPtoPDFconversion=\toks16
+) (/usr/share/texlive/texmf-dist/tex/generic/oberdiek/pdftexcmds.sty
+Package: pdftexcmds 2016/05/21 v0.22 Utility functions of pdfTeX for LuaTeX (HO
+)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ifluatex.sty
+Package: ifluatex 2016/05/16 v1.4 Provides the ifluatex switch (HO)
+Package ifluatex Info: LuaTeX not detected.
+)
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ifpdf.sty
+Package: ifpdf 2016/05/14 v3.1 Provides the ifpdf switch
+)
+Package pdftexcmds Info: LuaTeX not detected.
+Package pdftexcmds Info: \pdf@primitive is available.
+Package pdftexcmds Info: \pdf@ifprimitive is available.
+Package pdftexcmds Info: \pdfdraftmode found.
+)
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/epstopdf-base.sty
+Package: epstopdf-base 2016/05/15 v2.6 Base part for package epstopdf
+
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/grfext.sty
+Package: grfext 2016/05/16 v1.2 Manage graphics extensions (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/kvdefinekeys.sty
+Package: kvdefinekeys 2016/05/16 v1.4 Define keys (HO)
+))
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/kvoptions.sty
+Package: kvoptions 2016/05/16 v3.12 Key value format for package options (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/kvsetkeys.sty
+Package: kvsetkeys 2016/05/16 v1.17 Key value parser (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/etexcmds.sty
+Package: etexcmds 2016/05/16 v1.6 Avoid name clashes with e-TeX commands (HO)
+Package etexcmds Info: Could not find \expanded.
+(etexcmds)             That can mean that you are not using pdfTeX 1.50 or
+(etexcmds)             that some package has redefined \expanded.
+(etexcmds)             In the latter case, load this package earlier.
+)))
+Package epstopdf-base Info: Redefining graphics rule for `.eps' on input line 4
+38.
+Package grfext Info: Graphics extension search list:
+(grfext)             [.png,.pdf,.jpg,.mps,.jpeg,.jbig2,.jb2,.PNG,.PDF,.JPG,.JPE
+G,.JBIG2,.JB2,.eps]
+(grfext)             \AppendGraphicsExtensions on input line 456.
+
+(/usr/share/texlive/texmf-dist/tex/latex/latexconfig/epstopdf-sys.cfg
+File: epstopdf-sys.cfg 2010/07/13 v1.3 Configuration of (r)epstopdf for TeX Liv
+e
+))
+Package caption Info: Begin \AtBeginDocument code.
+Package caption Info: End \AtBeginDocument code.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <12> on input line 9.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <8> on input line 9.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <6> on input line 9.
+
+
+LaTeX Warning: No \author given.
+
+
+Underfull \hbox (badness 10000) in paragraph at lines 13--15
+
+ []
+
+<../pics/DSCN2180.JPG, id=1, 803.0pt x 602.25pt>
+File: ../pics/DSCN2180.JPG Graphic file (type jpg)
+ <use ../pics/DSCN2180.JPG>
+Package pdftex.def Info: ../pics/DSCN2180.JPG used on input line 16.
+(pdftex.def)             Requested size: 321.1943pt x 240.89572pt.
+
+
+Package caption Warning: \captionsetup{type*=...} or \captionof
+(caption)                outside box or environment on input line 17.
+See the caption package documentation for explanation.
+
+LaTeX Font Info:    Try loading font information for OMS+cmr on input line 22.
+(/usr/share/texlive/texmf-dist/tex/latex/base/omscmr.fd
+File: omscmr.fd 2014/09/29 v2.5h Standard LaTeX font definitions
+)
+LaTeX Font Info:    Font shape `OMS/cmr/m/n' in size <10.95> not available
+(Font)              Font shape `OMS/cmsy/m/n' tried instead on input line 22.
+ [1
+
+{/var/lib/texmf/fonts/map/pdftex/updmap/pdftex.map} <../pics/DSCN2180.JPG>]
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <10.95> on input line 31.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <9> on input line 31.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <5> on input line 31.
+
+Underfull \hbox (badness 10000) in paragraph at lines 47--48
+[]\OT1/cmr/m/n/10.95 https://thecavepearlproject.org/2019/02/25/no-parts-temper
+ature-
+ []
+
+[2]
+Underfull \hbox (badness 10000) in paragraph at lines 66--68
+
+ []
+
+[3] <../pics/DSCN2610.JPG, id=22, 803.0pt x 602.25pt>
+File: ../pics/DSCN2610.JPG Graphic file (type jpg)
+
+<use ../pics/DSCN2610.JPG>
+Package pdftex.def Info: ../pics/DSCN2610.JPG used on input line 70.
+(pdftex.def)             Requested size: 281.05421pt x 210.79065pt.
+ [4 <../pics/DSCN2610.JPG>]
+<../pics/esr_impedance_capacitance.png, id=26, 697.10437pt x 421.69917pt>
+File: ../pics/esr_impedance_capacitance.png Graphic file (type png)
+
+<use ../pics/esr_impedance_capacitance.png>
+Package pdftex.def Info: ../pics/esr_impedance_capacitance.png used on input li
+ne 81.
+(pdftex.def)             Requested size: 348.55133pt x 210.84906pt.
+ [5 <../pics/esr_impedance_capacitance.png (PNG copy)>]
+Overfull \hbox (13.6647pt too wide) in paragraph at lines 89--89
+[] \OT1/cmtt/m/n/10.95 https://en.wikipedia.org/w/index.php\title=Aluminum_elec
+trolytic 
+ []
+
+[6]
+Underfull \hbox (badness 10000) in paragraph at lines 121--122
+[]\OT1/cmr/m/n/10.95 Various, \OT1/cmr/m/it/10.95 https://www.eevblog.com/forum
+/projects/dreaded-
+ []
+
+
+Underfull \hbox (badness 10000) in paragraph at lines 121--122
+\OT1/cmr/m/it/10.95 alternator-whine-in-car-stereo/25/ \OT1/cmr/m/n/10.95 Re-tr
+ieved 2020-02-21. see
+ []
+
+
+Underfull \hbox (badness 10000) in paragraph at lines 121--122
+\OT1/cmr/m/n/10.95 also https://www.eevblog.com/forum/beginners/car-engine-sign
+al-
+ []
+
+
+Underfull \hbox (badness 10000) in paragraph at lines 124--125
+[]\OT1/cmr/m/it/10.95 https://partofthething.com/thoughts/building-a-low-pass-f
+ilter-to-
+ []
+
+[7] (./22.aux) ) 
+Here is how much of TeX's memory you used:
+ 2617 strings out of 494945
+ 41908 string characters out of 6181032
+ 96839 words of memory out of 5000000
+ 5901 multiletter control sequences out of 15000+600000
+ 10544 words of font info for 37 fonts, out of 8000000 for 9000
+ 14 hyphenation exceptions out of 8191
+ 39i,8n,39p,867b,211s stack positions out of 5000i,500n,10000p,200000b,80000s
+</usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/c
+mbx10.pfb></usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmbx12.
+pfb></usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmr10.pfb></u
+sr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmr12.pfb></usr/shar
+e/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmr6.pfb></usr/share/texliv
+e/texmf-dist/fonts/type1/public/amsfonts/cm/cmr8.pfb></usr/share/texlive/texmf-
+dist/fonts/type1/public/amsfonts/cm/cmr9.pfb></usr/share/texlive/texmf-dist/fon
+ts/type1/public/amsfonts/cm/cmsy10.pfb></usr/share/texlive/texmf-dist/fonts/typ
+e1/public/amsfonts/cm/cmti10.pfb></usr/share/texlive/texmf-dist/fonts/type1/pub
+lic/amsfonts/cm/cmtt10.pfb>
+Output written on 22.pdf (7 pages, 544291 bytes).
+PDF statistics:
+ 71 PDF objects out of 1000 (max. 8388607)
+ 48 compressed objects within 1 object stream
+ 0 named destinations out of 1000 (max. 500000)
+ 16 words of extra memory for PDF output out of 10000 (max. 10000000)
+

Car_Stereo_Replacement/docs/22.tex

@@ -0,0 +1,127 @@
+\documentclass[11pt]{article}
+%Gummi|065|=)
+\title{\textbf{Car Stereo Replacement}}
+\usepackage{graphicx,caption}
+%\author{Steak Electronics}
+\date{02/13/20}
+\begin{document}
+
+\maketitle
+%\tableofcontents
+
+\section{Car Stereo Replacement}
+Replacing a car stereo. I could just go to ebay, and buy a used car stereo, but where's the fun in that? Let's DIY a car stereo from a PCB used as a frontplate, a connector for my vehicle, and an audio amplifier. I'll connect in signal from an audio player.
+\\
+
+\includegraphics[scale=0.4]{../pics/DSCN2180.JPG}
+\captionof{figure}{PCB rev 1}
+
+\subsection{Items Included}
+I thought I would include the following:
+\begin{itemize}
+\item Arduino Nano
+\item Voltage and Gnd Breakout
+\item I2C Display
+\item Voltage Readout (of BAT)
+\item Current Readout (being drawn)
+\item Amplifier ``Lvpin LP-838''
+\end{itemize}
+I also wanted to have the connectors that eurorack and synth designers use for mono audio cables, but the cables turned out too expensive. The current readout didn't work initially, and I haven't gotten to fixing it yet.
+\subsubsection{I2C OLED display}
+Just for fun, I bought an I2C oled display and am going to use it to display something.\footnote{It's an Arduino Uno, you can put almost anything on this.} Notes on this:
+Using the adafruit SSD1306 and GFX library (this procedure is well covered in other places), you can load an example sketch and get it running. First thing to change is to remove the Adafruit logo and replace it with my own. Let's do that.
+
+From https://design.goeszen.com/convert-image-for-oled-display.html
+\begin{verbatim}
+I'm on Linux here and found that the readily-available 
+ImageMagick package will do the trick for you without
+ any scripting. And runs on the CLI! Simple as that:
+
+    convert some_image.png some.image.mono
+\end{verbatim}
+That's efficient. But it didn't really work out. Too much work, I don't need it that bad. Have to convert it to something the c compiler can read. I instead, just deleted their logo. Good enough for now.
+\subsubsection{Internal AVR Temperature Sensor}
+
+I setup the code to read from the internal temp sensor on the duino. However there is also this:
+
+https://thecavepearlproject.org/2019/02/25/no-parts-temperature-measurement-with-arduino-pro-mini-to-0-005c-or-better/
+
+This would be something to do for more resolution. The built in sensor is not very good, so this above link would be great. Hack a day also covers it. 
+
+\subsection{Wiring Pinout is wrong on Internet - Cable has labels}
+I looked at the picture I have detailing the pinout of my car connector (Delco Delphi radio wiring diagram.jpg in resources). It's close, but not 100\% correct. I found that the cable itself has small text labels on each wire which explain which everything does. I didn't notice earlier, as I didn't look close enough (and no one mentioned this).
+
+\subsection{Arduino VReg Blowout}
+I had a knock off Arduino Nano, and the vreg blew out. I have some other vregs to replace it. I didn't have this problem with an Uno that I use as a ceiling dome light. Although that one is not left on as long, usually. 
+
+\subsection{Amplifier}
+The amplifier I used is one of the cheapest avialable on ebay. I'm not proud. I'm poor. I had to take it apart, and reseat the amplifier ICs as the tab was not making contact with the chassis for one of them. I also added thermal paste. This amp is underpowered for my car, and may need replacing. It gets a bit hot.
+
+Some other issues with this amplifier are that the output connectors can get pushed back, there is only one output connector option, and it must run on battery power, as a 12V 1A or 2A will not power it. Finally, there is a 6V DC bias on output. No output audio isolation, which means you get car noise.
+
+\subsection{AC Audio Coupling to Remove DC Noise from Auto}
+I had some fun with this one. Many videos on this in the video folder. I started with the speakers being directly fed by the amplifier. This worked, but there was some noise coming through. Cars are noisy, this is not surprising. I would've preferred the amplifier to isolate the outputs, but no luck... At this point, I considered two options to block DC and allow AC. 1) Use a transformer. 2) Use capacitors.\footnote{A third option would've been to use a second set of batteries, but that would be laborious.}
+
+\subsubsection{Ground Isolator}
+I had been given a Ground isolator, which was two small transformers on a pcb intended to pass audio from a car powered signal source into the car speakers. I tried this isolator on the output of the speakers, and while it worked, the volume was lower, and it was impractical. I knew as soon as I heard the volume, that the issue was an impedance matching problem. The transformers were too small. They were intended for signal sources, not amplifier outputs. Onto option \#2.
+\\
+
+\begin{center}
+\includegraphics[scale=0.35]{../pics/DSCN2610.JPG}
+\captionof{figure}{Ground Loop Isolator.}
+\end{center}
+\subsubsection{Capacitor Audio Coupling}
+My initial thoughts here were: ``Let's be careful and use non polarized caps''. I bought some 0.22uf and 0.022uf polyester film capacitors at Electronics Plus, the local radioshack replacement, and tried them. No sound. After adjusting the connectors on the amp (which were admittedly loose - it's easy to push them back on the amplifier if you are not careful) I found that the capacitors didn't work. One problem was evident in the oscope. I only used one capacitor on the + output of the speaker amp, but the Amp biases the signal 6 volts. So I needed two. After that was resolved, the signal came through on the output of the capacitor, as viewed on the scope, however there was no sound output. I tried the safe way. It's time to break some rules. 
+
+I grabbed some 1uf (electrolytic polarized) caps I had, and tried these. Again, no sound. Not giving up, I grabbed some 1000uf 'lytics, and tried once more. Now it worked.
+
+\subsubsection{Impedance / ESR of capacitors failing to pass enough power of signal}
+Capacitors are rated for impedance. Some data sheets also call this ESR, it appears after a quick look. It's either in there as impedance or ESR. It's not initially an issue if you are using the capacitor as a DC reservoir, but if you use it in an AC coupling situation then things get interesting. A high impedance, or ESR will block what a low one won't. In this example, it's as simple as the Amplfier either being able to power a speaker or not. Higher capacity caps will have lower impedance. See the picture. Other brands put impedance in a graph, or just call it impedance. 
+
+\includegraphics[scale=0.5]{../pics/esr_impedance_capacitance.png}
+\captionof{figure}{Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.}
+
+\subsubsection{Wikipedia on Impedance}
+
+\emph{In general, a capacitor is seen as a storage component for electric energy. But this is only one capacitor function. A capacitor can also act as an AC resistor. Especially aluminum electrolytic capacitors are used in many applications as a decoupling capacitors to filter or bypass undesired biased AC frequencies to the ground or for capacitive coupling of audio AC signals. Then the dielectric is used only for blocking DC. For such applications the AC resistance, the impedance is as important as the capacitance value. }
+\begin{verbatim} https://en.wikipedia.org/w/index.php\title=Aluminum_electrolytic
+_capacitor&oldid=940281525
+\end{verbatim}
+Essentially, what I learned today.
+
+\subsection{DIY Amp}
+I was flipping through Practical Electronics for Inventors\cite{Scherz}(page 959), when I came across an audio amplifier. He also gives one at the chapter on Semiconductors (pg. 467), although the former is more detailed. With a reasonably simple schematic available, and a high likelihood of it working, I say why not: let's build it up.
+
+I've noticed that the ``Lvpin LP-838'' amplifier I'm using is underpowered for my two front speakers \footnote{Although it seems it would work for one channel, so two of them might be enough. It's rated for 20W, so that is about 15-20W per channel req'd. It works at 20W for both, just that it heats up too much. Multiple ebay sellers have it misquoted at 200W. Just an extra 0, no biggie. Based on all this, it appears each channel of my car speaker needs about 15 watts to be on the safe side. The example schematic is 16 watts. Two should suffice.}, so I will make two of the provided 16 watt amps.
+
+\subsubsection{LM383 is Obsolete}
+That explains why I haven't heard of it. The chip is obsolete. Some sell it on ebay for about \$5 each.
+
+As a different route, could I use some other power amplifier op amp, with the same pinout? Hm... Aha, the LM1875 has the same pinout. Let's use that.\footnote{How did I find this? I searched Digikey for the LM383 sold by rochester, noted it was it the category of Linear - Amplifiers - Audio, chose that, then searched for everything in the same package (TO220-5). Came right up. If this hadn't worked, I would've wanted to try other sites: Farnells, Mouser, etc...}
+
+Will it work with the same schematic? Questionable. May still need to buy a LM383, along with the LM1875, as backup. I might also try a generic power op amp.
+
+Amplfiers are the expensive bom item here.
+
+\subsection{Noise remains with Speaker Isolation}
+I've isolated the speakers from DC with the caps, but noise remains. My next idea was a DC-DC isolated supply. But, I found two threads on eevblog forums\cite{eevblog}, and they recommend a power line filter (they also mention the isolated supply). A filter with a coil and cap (2200uf even low enough) I can quickly build up.
+
+I also want to fix up my portable CRO, I obtained the other day. That needs batteries.
+
+One thing I noticed, is that the amplifier seems to no longer heat up, since the caps were added. Perhaps the DC bias was the cause. I need to confirm this.
+ 
+
+\subsection{References}
+\begin{thebibliography}{99}
+\bibitem{Scherz}
+  Paul Scherz, and Simon Monk,
+  \emph{Practical Electronics for Inventors}, fourth edition - 2016, McGraw Hill.
+
+\bibitem{eevblog}
+  Various, \emph{https://www.eevblog.com/forum/projects/dreaded-alternator-whine-in-car-stereo/25/} Retrieved 2020-02-21. see also https://www.eevblog.com/forum/beginners/car-engine-signal-interference-with-cell-phone/
+
+\bibitem{partofthe}
+  \emph{https://partofthething.com/thoughts/building-a-low-pass-filter-to-remove-alternator-whine-in-my-car/}. Picture guide and showing basic build in project box. Eevblog users mention you may be able to use the secondary of a transformer, to avoid building the coil.
+  \end{thebibliography}
+
+\end{document}

Car_Stereo_Replacement/docs/22.tex~

@@ -0,0 +1,127 @@
+\documentclass[11pt]{article}
+%Gummi|065|=)
+\title{\textbf{Car Stereo Replacement}}
+\usepackage{graphicx,caption}
+%\author{Steak Electronics}
+\date{02/13/20}
+\begin{document}
+
+\maketitle
+\tableofcontents
+
+\section{Car Stereo Replacement}
+Replacing a car stereo. I could just go to ebay, and buy a used car stereo, but where's the fun in that? Let's DIY a car stereo from a PCB used as a frontplate, a connector for my vehicle, and an audio amplifier. I'll connect in signal from an audio player.
+\\
+
+\includegraphics[scale=0.4]{../pics/DSCN2180.JPG}
+\captionof{figure}{PCB rev 1}
+
+\subsection{Items Included}
+I thought I would include the following:
+\begin{itemize}
+\item Arduino Nano
+\item Voltage and Gnd Breakout
+\item I2C Display
+\item Voltage Readout (of BAT)
+\item Current Readout (being drawn)
+\item Amplifier ``Lvpin LP-838''
+\end{itemize}
+I also wanted to have the connectors that eurorack and synth designers use for mono audio cables, but the cables turned out too expensive. The current readout didn't work initially, and I haven't gotten to fixing it yet.
+\subsubsection{I2C OLED display}
+Just for fun, I bought an I2C oled display and am going to use it to display something.\footnote{It's an Arduino Uno, you can put almost anything on this.} Notes on this:
+Using the adafruit SSD1306 and GFX library (this procedure is well covered in other places), you can load an example sketch and get it running. First thing to change is to remove the Adafruit logo and replace it with my own. Let's do that.
+
+From https://design.goeszen.com/convert-image-for-oled-display.html
+\begin{verbatim}
+I'm on Linux here and found that the readily-available 
+ImageMagick package will do the trick for you without
+ any scripting. And runs on the CLI! Simple as that:
+
+    convert some_image.png some.image.mono
+\end{verbatim}
+That's efficient. But it didn't really work out. Too much work, I don't need it that bad. Have to convert it to something the c compiler can read. I instead, just deleted their logo. Good enough for now.
+\subsubsection{Internal AVR Temperature Sensor}
+
+I setup the code to read from the internal temp sensor on the duino. However there is also this:
+
+https://thecavepearlproject.org/2019/02/25/no-parts-temperature-measurement-with-arduino-pro-mini-to-0-005c-or-better/
+
+This would be something to do for more resolution. The built in sensor is not very good, so this above link would be great. Hack a day also covers it. 
+
+\subsection{Wiring Pinout is wrong on Internet - Cable has labels}
+I looked at the picture I have detailing the pinout of my car connector (Delco Delphi radio wiring diagram.jpg in resources). It's close, but not 100\% correct. I found that the cable itself has small text labels on each wire which explain which everything does. I didn't notice earlier, as I didn't look close enough (and no one mentioned this).
+
+\subsection{Arduino VReg Blowout}
+I had a knock off Arduino Nano, and the vreg blew out. I have some other vregs to replace it. I didn't have this problem with an Uno that I use as a ceiling dome light. Although that one is not left on as long, usually. 
+
+\subsection{Amplifier}
+The amplifier I used is one of the cheapest avialable on ebay. I'm not proud. I'm poor. I had to take it apart, and reseat the amplifier ICs as the tab was not making contact with the chassis for one of them. I also added thermal paste. This amp is underpowered for my car, and may need replacing. It gets a bit hot.
+
+Some other issues with this amplifier are that the output connectors can get pushed back, there is only one output connector option, and it must run on battery power, as a 12V 1A or 2A will not power it. Finally, there is a 6V DC bias on output. No output audio isolation, which means you get car noise.
+
+\subsection{AC Audio Coupling to Remove DC Noise from Auto}
+I had some fun with this one. Many videos on this in the video folder. I started with the speakers being directly fed by the amplifier. This worked, but there was some noise coming through. Cars are noisy, this is not surprising. I would've preferred the amplifier to isolate the outputs, but no luck... At this point, I considered two options to block DC and allow AC. 1) Use a transformer. 2) Use capacitors.\footnote{A third option would've been to use a second set of batteries, but that would be laborious.}
+
+\subsubsection{Ground Isolator}
+I had been given a Ground isolator, which was two small transformers on a pcb intended to pass audio from a car powered signal source into the car speakers. I tried this isolator on the output of the speakers, and while it worked, the volume was lower, and it was impractical. I knew as soon as I heard the volume, that the issue was an impedance matching problem. The transformers were too small. They were intended for signal sources, not amplifier outputs. Onto option \#2.
+\\
+
+\begin{center}
+\includegraphics[scale=0.35]{../pics/DSCN2610.JPG}
+\captionof{figure}{Ground Loop Isolator.}
+\end{center}
+\subsubsection{Capacitor Audio Coupling}
+My initial thoughts here were: ``Let's be careful and use non polarized caps''. I bought some 0.22uf and 0.022uf polyester film capacitors at Electronics Plus, the local radioshack replacement, and tried them. No sound. After adjusting the connectors on the amp (which were admittedly loose - it's easy to push them back on the amplifier if you are not careful) I found that the capacitors didn't work. One problem was evident in the oscope. I only used one capacitor on the + output of the speaker amp, but the Amp biases the signal 6 volts. So I needed two. After that was resolved, the signal came through on the output of the capacitor, as viewed on the scope, however there was no sound output. I tried the safe way. It's time to break some rules. 
+
+I grabbed some 1uf (electrolytic polarized) caps I had, and tried these. Again, no sound. Not giving up, I grabbed some 1000uf 'lytics, and tried once more. Now it worked.
+
+\subsubsection{Impedance / ESR of capacitors failing to pass enough power of signal}
+Capacitors are rated for impedance. Some data sheets also call this ESR, it appears after a quick look. It's either in there as impedance or ESR. It's not initially an issue if you are using the capacitor as a DC reservoir, but if you use it in an AC coupling situation then things get interesting. A high impedance, or ESR will block what a low one won't. In this example, it's as simple as the Amplfier either being able to power a speaker or not. Higher capacity caps will have lower impedance. See the picture. Other brands put impedance in a graph, or just call it impedance. 
+
+\includegraphics[scale=0.5]{../pics/esr_impedance_capacitance.png}
+\captionof{figure}{Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.}
+
+\subsubsection{Wikipedia on Impedance}
+
+\emph{In general, a capacitor is seen as a storage component for electric energy. But this is only one capacitor function. A capacitor can also act as an AC resistor. Especially aluminum electrolytic capacitors are used in many applications as a decoupling capacitors to filter or bypass undesired biased AC frequencies to the ground or for capacitive coupling of audio AC signals. Then the dielectric is used only for blocking DC. For such applications the AC resistance, the impedance is as important as the capacitance value. }
+\begin{verbatim} https://en.wikipedia.org/w/index.php\title=Aluminum_electrolytic
+_capacitor&oldid=940281525
+\end{verbatim}
+Essentially, what I learned today.
+
+\subsection{DIY Amp}
+I was flipping through Practical Electronics for Inventors\cite{Scherz}(page 959), when I came across an audio amplifier. He also gives one at the chapter on Semiconductors (pg. 467), although the former is more detailed. With a reasonably simple schematic available, and a high likelihood of it working, I say why not: let's build it up.
+
+I've noticed that the ``Lvpin LP-838'' amplifier I'm using is underpowered for my two front speakers \footnote{Although it seems it would work for one channel, so two of them might be enough. It's rated for 20W, so that is about 15-20W per channel req'd. It works at 20W for both, just that it heats up too much. Multiple ebay sellers have it misquoted at 200W. Just an extra 0, no biggie. Based on all this, it appears each channel of my car speaker needs about 15 watts to be on the safe side. The example schematic is 16 watts. Two should suffice.}, so I will make two of the provided 16 watt amps.
+
+\subsubsection{LM383 is Obsolete}
+That explains why I haven't heard of it. The chip is obsolete. Some sell it on ebay for about \$5 each.
+
+As a different route, could I use some other power amplifier op amp, with the same pinout? Hm... Aha, the LM1875 has the same pinout. Let's use that.\footnote{How did I find this? I searched Digikey for the LM383 sold by rochester, noted it was it the category of Linear - Amplifiers - Audio, chose that, then searched for everything in the same package (TO220-5). Came right up. If this hadn't worked, I would've wanted to try other sites: Farnells, Mouser, etc...}
+
+Will it work with the same schematic? Questionable. May still need to buy a LM383, along with the LM1875, as backup. I might also try a generic power op amp.
+
+Amplfiers are the expensive bom item here.
+
+\subsection{Noise remains with Speaker Isolation}
+I've isolated the speakers from DC with the caps, but noise remains. My next idea was a DC-DC isolated supply. But, I found two threads on eevblog forums\cite{eevblog}, and they recommend a power line filter (they also mention the isolated supply). A filter with a coil and cap (2200uf even low enough) I can quickly build up.
+
+I also want to fix up my portable CRO, I obtained the other day. That needs batteries.
+
+One thing I noticed, is that the amplifier seems to no longer heat up, since the caps were added. Perhaps the DC bias was the cause. I need to confirm this.
+ 
+
+\subsection{References}
+\begin{thebibliography}{99}
+\bibitem{Scherz}
+  Paul Scherz, and Simon Monk,
+  \emph{Practical Electronics for Inventors}, fourth edition - 2016, McGraw Hill.
+
+\bibitem{eevblog}
+  Various, \emph{https://www.eevblog.com/forum/projects/dreaded-alternator-whine-in-car-stereo/25/} Retrieved 2020-02-21. see also https://www.eevblog.com/forum/beginners/car-engine-signal-interference-with-cell-phone/
+
+\bibitem{partofthe}
+  \emph{https://partofthething.com/thoughts/building-a-low-pass-filter-to-remove-alternator-whine-in-my-car/}. Picture guide and showing basic build in project box. Eevblog users mention you may be able to use the secondary of a transformer, to avoid building the coil.
+  \end{thebibliography}
+
+\end{document}

Car_Stereo_Replacement/docs/22.toc

@@ -0,0 +1,16 @@
+\contentsline {section}{\numberline {1}Car Stereo Replacement}{1}
+\contentsline {subsection}{\numberline {1.1}Items Included}{2}
+\contentsline {subsubsection}{\numberline {1.1.1}I2C OLED display}{3}
+\contentsline {subsubsection}{\numberline {1.1.2}Internal AVR Temperature Sensor}{3}
+\contentsline {subsection}{\numberline {1.2}Wiring Pinout is wrong on Internet - Cable has labels}{3}
+\contentsline {subsection}{\numberline {1.3}Arduino VReg Blowout}{3}
+\contentsline {subsection}{\numberline {1.4}Amplifier}{4}
+\contentsline {subsection}{\numberline {1.5}AC Audio Coupling to Remove DC Noise from Auto}{4}
+\contentsline {subsubsection}{\numberline {1.5.1}Ground Isolator}{4}
+\contentsline {subsubsection}{\numberline {1.5.2}Capacitor Audio Coupling}{5}
+\contentsline {subsubsection}{\numberline {1.5.3}Impedance / ESR of capacitors failing to pass enough power of signal}{5}
+\contentsline {subsubsection}{\numberline {1.5.4}Wikipedia on Impedance}{6}
+\contentsline {subsection}{\numberline {1.6}DIY Amp}{7}
+\contentsline {subsubsection}{\numberline {1.6.1}LM383 is Obsolete}{7}
+\contentsline {subsection}{\numberline {1.7}Noise remains with Speaker Isolation}{7}
+\contentsline {subsection}{\numberline {1.8}References}{8}

Car_Stereo_Replacement/docs/23.aux

@@ -0,0 +1,26 @@
+\relax 
+\@writefile{toc}{\contentsline {section}{\numberline {1}Car Stereo Replacement}{1}}
+\@writefile{lof}{\contentsline {figure}{\numberline {1}{\ignorespaces PCB rev 1\relax }}{1}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.1}Items Included}{1}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.1.1}I2C OLED display}{2}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.1.2}Internal AVR Temperature Sensor}{2}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.2}Wiring Pinout is wrong on Internet - Cable has labels}{3}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.3}Arduino VReg Blowout}{3}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.4}Amplifier}{3}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.5}AC Audio Coupling to Remove DC Noise from Auto}{3}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.5.1}Ground Isolator}{4}}
+\@writefile{lof}{\contentsline {figure}{\numberline {2}{\ignorespaces Ground Loop Isolator.\relax }}{4}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.5.2}Capacitor Audio Coupling}{4}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.5.3}Impedance / ESR of capacitors failing to pass enough power of signal}{5}}
+\@writefile{lof}{\contentsline {figure}{\numberline {3}{\ignorespaces Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.\relax }}{5}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.5.4}Wikipedia on Impedance}{5}}
+\citation{Scherz}
+\citation{eevblog}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.6}DIY Amp}{6}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.6.1}LM383 is Obsolete}{6}}
+\bibcite{Scherz}{1}
+\bibcite{eevblog}{2}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.7}Noise remains with Speaker Isolation}{7}}
+\@writefile{lof}{\contentsline {figure}{\numberline {4}{\ignorespaces This picture was more difficult to download than it should've been. Spent 3 minutes on this. At least its not a discourse javascript pile of trash.\relax }}{7}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.8}References}{7}}
+\bibcite{partofthe}{3}

Car_Stereo_Replacement/docs/23.log

@@ -0,0 +1,288 @@
+This is pdfTeX, Version 3.14159265-2.6-1.40.17 (TeX Live 2016/Debian) (preloaded format=pdflatex 2019.8.17)  20 MAR 2020 22:14
+entering extended mode
+ restricted \write18 enabled.
+ %&-line parsing enabled.
+**/home/layoutdev/Desktop/code/documentation_general/Electronics_Projects_2019/
+Car_Stereo_Replacement/docs/23.tex
+
+(/home/layoutdev/Desktop/code/documentation_general/Electronics_Projects_2019/C
+ar_Stereo_Replacement/docs/23.tex
+LaTeX2e <2017/01/01> patch level 3
+Babel <3.9r> and hyphenation patterns for 3 language(s) loaded.
+(/usr/share/texlive/texmf-dist/tex/latex/base/article.cls
+Document Class: article 2014/09/29 v1.4h Standard LaTeX document class
+(/usr/share/texlive/texmf-dist/tex/latex/base/size11.clo
+File: size11.clo 2014/09/29 v1.4h Standard LaTeX file (size option)
+)
+\c@part=\count79
+\c@section=\count80
+\c@subsection=\count81
+\c@subsubsection=\count82
+\c@paragraph=\count83
+\c@subparagraph=\count84
+\c@figure=\count85
+\c@table=\count86
+\abovecaptionskip=\skip41
+\belowcaptionskip=\skip42
+\bibindent=\dimen102
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/graphicx.sty
+Package: graphicx 2014/10/28 v1.0g Enhanced LaTeX Graphics (DPC,SPQR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/keyval.sty
+Package: keyval 2014/10/28 v1.15 key=value parser (DPC)
+\KV@toks@=\toks14
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/graphics.sty
+Package: graphics 2016/10/09 v1.0u Standard LaTeX Graphics (DPC,SPQR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/trig.sty
+Package: trig 2016/01/03 v1.10 sin cos tan (DPC)
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics-cfg/graphics.cfg
+File: graphics.cfg 2016/06/04 v1.11 sample graphics configuration
+)
+Package graphics Info: Driver file: pdftex.def on input line 99.
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics-def/pdftex.def
+File: pdftex.def 2017/01/12 v0.06k Graphics/color for pdfTeX
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/infwarerr.sty
+Package: infwarerr 2016/05/16 v1.4 Providing info/warning/error messages (HO)
+)
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ltxcmds.sty
+Package: ltxcmds 2016/05/16 v1.23 LaTeX kernel commands for general use (HO)
+)
+\Gread@gobject=\count87
+))
+\Gin@req@height=\dimen103
+\Gin@req@width=\dimen104
+)
+(/usr/share/texlive/texmf-dist/tex/latex/caption/caption.sty
+Package: caption 2016/02/21 v3.3-144 Customizing captions (AR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/caption/caption3.sty
+Package: caption3 2016/05/22 v1.7-166 caption3 kernel (AR)
+Package caption3 Info: TeX engine: e-TeX on input line 67.
+\captionmargin=\dimen105
+\captionmargin@=\dimen106
+\captionwidth=\dimen107
+\caption@tempdima=\dimen108
+\caption@indent=\dimen109
+\caption@parindent=\dimen110
+\caption@hangindent=\dimen111
+)
+\c@ContinuedFloat=\count88
+) (./23.aux)
+\openout1 = `23.aux'.
+
+LaTeX Font Info:    Checking defaults for OML/cmm/m/it on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for T1/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OT1/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OMS/cmsy/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OMX/cmex/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for U/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+
+(/usr/share/texlive/texmf-dist/tex/context/base/mkii/supp-pdf.mkii
+[Loading MPS to PDF converter (version 2006.09.02).]
+\scratchcounter=\count89
+\scratchdimen=\dimen112
+\scratchbox=\box26
+\nofMPsegments=\count90
+\nofMParguments=\count91
+\everyMPshowfont=\toks15
+\MPscratchCnt=\count92
+\MPscratchDim=\dimen113
+\MPnumerator=\count93
+\makeMPintoPDFobject=\count94
+\everyMPtoPDFconversion=\toks16
+) (/usr/share/texlive/texmf-dist/tex/generic/oberdiek/pdftexcmds.sty
+Package: pdftexcmds 2016/05/21 v0.22 Utility functions of pdfTeX for LuaTeX (HO
+)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ifluatex.sty
+Package: ifluatex 2016/05/16 v1.4 Provides the ifluatex switch (HO)
+Package ifluatex Info: LuaTeX not detected.
+)
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ifpdf.sty
+Package: ifpdf 2016/05/14 v3.1 Provides the ifpdf switch
+)
+Package pdftexcmds Info: LuaTeX not detected.
+Package pdftexcmds Info: \pdf@primitive is available.
+Package pdftexcmds Info: \pdf@ifprimitive is available.
+Package pdftexcmds Info: \pdfdraftmode found.
+)
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/epstopdf-base.sty
+Package: epstopdf-base 2016/05/15 v2.6 Base part for package epstopdf
+
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/grfext.sty
+Package: grfext 2016/05/16 v1.2 Manage graphics extensions (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/kvdefinekeys.sty
+Package: kvdefinekeys 2016/05/16 v1.4 Define keys (HO)
+))
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/kvoptions.sty
+Package: kvoptions 2016/05/16 v3.12 Key value format for package options (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/kvsetkeys.sty
+Package: kvsetkeys 2016/05/16 v1.17 Key value parser (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/etexcmds.sty
+Package: etexcmds 2016/05/16 v1.6 Avoid name clashes with e-TeX commands (HO)
+Package etexcmds Info: Could not find \expanded.
+(etexcmds)             That can mean that you are not using pdfTeX 1.50 or
+(etexcmds)             that some package has redefined \expanded.
+(etexcmds)             In the latter case, load this package earlier.
+)))
+Package epstopdf-base Info: Redefining graphics rule for `.eps' on input line 4
+38.
+Package grfext Info: Graphics extension search list:
+(grfext)             [.png,.pdf,.jpg,.mps,.jpeg,.jbig2,.jb2,.PNG,.PDF,.JPG,.JPE
+G,.JBIG2,.JB2,.eps]
+(grfext)             \AppendGraphicsExtensions on input line 456.
+
+(/usr/share/texlive/texmf-dist/tex/latex/latexconfig/epstopdf-sys.cfg
+File: epstopdf-sys.cfg 2010/07/13 v1.3 Configuration of (r)epstopdf for TeX Liv
+e
+))
+Package caption Info: Begin \AtBeginDocument code.
+Package caption Info: End \AtBeginDocument code.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <12> on input line 9.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <8> on input line 9.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <6> on input line 9.
+
+
+LaTeX Warning: No \author given.
+
+
+Underfull \hbox (badness 10000) in paragraph at lines 13--15
+
+ []
+
+<../pics/DSCN2180.JPG, id=1, 803.0pt x 602.25pt>
+File: ../pics/DSCN2180.JPG Graphic file (type jpg)
+ <use ../pics/DSCN2180.JPG>
+Package pdftex.def Info: ../pics/DSCN2180.JPG used on input line 16.
+(pdftex.def)             Requested size: 321.1943pt x 240.89572pt.
+
+
+Package caption Warning: \captionsetup{type*=...} or \captionof
+(caption)                outside box or environment on input line 17.
+See the caption package documentation for explanation.
+
+LaTeX Font Info:    Try loading font information for OMS+cmr on input line 22.
+(/usr/share/texlive/texmf-dist/tex/latex/base/omscmr.fd
+File: omscmr.fd 2014/09/29 v2.5h Standard LaTeX font definitions
+)
+LaTeX Font Info:    Font shape `OMS/cmr/m/n' in size <10.95> not available
+(Font)              Font shape `OMS/cmsy/m/n' tried instead on input line 22.
+ [1
+
+{/var/lib/texmf/fonts/map/pdftex/updmap/pdftex.map} <../pics/DSCN2180.JPG>]
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <10.95> on input line 31.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <9> on input line 31.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <5> on input line 31.
+
+Underfull \hbox (badness 10000) in paragraph at lines 47--48
+[]\OT1/cmr/m/n/10.95 https://thecavepearlproject.org/2019/02/25/no-parts-temper
+ature-
+ []
+
+[2]
+Underfull \hbox (badness 10000) in paragraph at lines 66--68
+
+ []
+
+[3] <../pics/DSCN2610.JPG, id=22, 803.0pt x 602.25pt>
+File: ../pics/DSCN2610.JPG Graphic file (type jpg)
+
+<use ../pics/DSCN2610.JPG>
+Package pdftex.def Info: ../pics/DSCN2610.JPG used on input line 70.
+(pdftex.def)             Requested size: 281.05421pt x 210.79065pt.
+ [4 <../pics/DSCN2610.JPG>]
+<../pics/esr_impedance_capacitance.png, id=26, 697.10437pt x 421.69917pt>
+File: ../pics/esr_impedance_capacitance.png Graphic file (type png)
+
+<use ../pics/esr_impedance_capacitance.png>
+Package pdftex.def Info: ../pics/esr_impedance_capacitance.png used on input li
+ne 81.
+(pdftex.def)             Requested size: 348.55133pt x 210.84906pt.
+ [5 <../pics/esr_impedance_capacitance.png (PNG copy)>]
+Overfull \hbox (13.6647pt too wide) in paragraph at lines 89--89
+[] \OT1/cmtt/m/n/10.95 https://en.wikipedia.org/w/index.php\title=Aluminum_elec
+trolytic 
+ []
+
+[6] <../pics/LC_Filter.png, id=34, 589.4522pt x 206.27063pt>
+File: ../pics/LC_Filter.png Graphic file (type png)
+
+<use ../pics/LC_Filter.png>
+Package pdftex.def Info: ../pics/LC_Filter.png used on input line 116.
+(pdftex.def)             Requested size: 442.08806pt x 154.70258pt.
+
+Overfull \hbox (82.08806pt too wide) in paragraph at lines 116--117
+ [] 
+ []
+
+
+Underfull \hbox (badness 10000) in paragraph at lines 127--128
+[]\OT1/cmr/m/n/10.95 Various, \OT1/cmr/m/it/10.95 https://www.eevblog.com/forum
+/projects/dreaded-
+ []
+
+
+Underfull \hbox (badness 10000) in paragraph at lines 127--128
+\OT1/cmr/m/it/10.95 alternator-whine-in-car-stereo/25/ \OT1/cmr/m/n/10.95 Re-tr
+ieved 2020-02-21. see
+ []
+
+
+Underfull \hbox (badness 10000) in paragraph at lines 127--128
+\OT1/cmr/m/n/10.95 also https://www.eevblog.com/forum/beginners/car-engine-sign
+al-
+ []
+
+[7 <../pics/LC_Filter.png>]
+Underfull \hbox (badness 10000) in paragraph at lines 130--131
+[]\OT1/cmr/m/it/10.95 https://partofthething.com/thoughts/building-a-low-pass-f
+ilter-to-
+ []
+
+[8] (./23.aux) ) 
+Here is how much of TeX's memory you used:
+ 2622 strings out of 494945
+ 42024 string characters out of 6181032
+ 96839 words of memory out of 5000000
+ 5905 multiletter control sequences out of 15000+600000
+ 10544 words of font info for 37 fonts, out of 8000000 for 9000
+ 14 hyphenation exceptions out of 8191
+ 39i,8n,39p,867b,211s stack positions out of 5000i,500n,10000p,200000b,80000s
+</usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/c
+mbx10.pfb></usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmbx12.
+pfb></usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmr10.pfb></u
+sr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmr12.pfb></usr/shar
+e/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmr6.pfb></usr/share/texliv
+e/texmf-dist/fonts/type1/public/amsfonts/cm/cmr8.pfb></usr/share/texlive/texmf-
+dist/fonts/type1/public/amsfonts/cm/cmr9.pfb></usr/share/texlive/texmf-dist/fon
+ts/type1/public/amsfonts/cm/cmsy10.pfb></usr/share/texlive/texmf-dist/fonts/typ
+e1/public/amsfonts/cm/cmti10.pfb></usr/share/texlive/texmf-dist/fonts/type1/pub
+lic/amsfonts/cm/cmtt10.pfb>
+Output written on 23.pdf (8 pages, 549677 bytes).
+PDF statistics:
+ 77 PDF objects out of 1000 (max. 8388607)
+ 51 compressed objects within 1 object stream
+ 0 named destinations out of 1000 (max. 500000)
+ 21 words of extra memory for PDF output out of 10000 (max. 10000000)
+

Car_Stereo_Replacement/docs/23.tex

@@ -0,0 +1,133 @@
+\documentclass[11pt]{article}
+%Gummi|065|=)
+\title{\textbf{Car Stereo Replacement}}
+\usepackage{graphicx,caption}
+%\author{Steak Electronics}
+\date{02/13/20}
+\begin{document}
+
+\maketitle
+%\tableofcontents
+
+\section{Car Stereo Replacement}
+Replacing a car stereo. I could just go to ebay, and buy a used car stereo, but where's the fun in that? Let's DIY a car stereo from a PCB used as a frontplate, a connector for my vehicle, and an audio amplifier. I'll connect in signal from an audio player.
+\\
+
+\includegraphics[scale=0.4]{../pics/DSCN2180.JPG}
+\captionof{figure}{PCB rev 1}
+
+\subsection{Items Included}
+I thought I would include the following:
+\begin{itemize}
+\item Arduino Nano
+\item Voltage and Gnd Breakout
+\item I2C Display
+\item Voltage Readout (of BAT)
+\item Current Readout (being drawn)
+\item Amplifier ``Lvpin LP-838''
+\end{itemize}
+I also wanted to have the connectors that eurorack and synth designers use for mono audio cables, but the cables turned out too expensive. The current readout didn't work initially, and I haven't gotten to fixing it yet.
+\subsubsection{I2C OLED display}
+Just for fun, I bought an I2C oled display and am going to use it to display something.\footnote{It's an Arduino Uno, you can put almost anything on this.} Notes on this:
+Using the adafruit SSD1306 and GFX library (this procedure is well covered in other places), you can load an example sketch and get it running. First thing to change is to remove the Adafruit logo and replace it with my own. Let's do that.
+
+From https://design.goeszen.com/convert-image-for-oled-display.html
+\begin{verbatim}
+I'm on Linux here and found that the readily-available 
+ImageMagick package will do the trick for you without
+ any scripting. And runs on the CLI! Simple as that:
+
+    convert some_image.png some.image.mono
+\end{verbatim}
+That's efficient. But it didn't really work out. Too much work, I don't need it that bad. Have to convert it to something the c compiler can read. I instead, just deleted their logo. Good enough for now.
+\subsubsection{Internal AVR Temperature Sensor}
+
+I setup the code to read from the internal temp sensor on the duino. However there is also this:
+
+https://thecavepearlproject.org/2019/02/25/no-parts-temperature-measurement-with-arduino-pro-mini-to-0-005c-or-better/
+
+This would be something to do for more resolution. The built in sensor is not very good, so this above link would be great. Hack a day also covers it. 
+
+\subsection{Wiring Pinout is wrong on Internet - Cable has labels}
+I looked at the picture I have detailing the pinout of my car connector (Delco Delphi radio wiring diagram.jpg in resources). It's close, but not 100\% correct. I found that the cable itself has small text labels on each wire which explain which everything does. I didn't notice earlier, as I didn't look close enough (and no one mentioned this).
+
+\subsection{Arduino VReg Blowout}
+I had a knock off Arduino Nano, and the vreg blew out. I have some other vregs to replace it. I didn't have this problem with an Uno that I use as a ceiling dome light. Although that one is not left on as long, usually. 
+
+\subsection{Amplifier}
+The amplifier I used is one of the cheapest avialable on ebay. I'm not proud. I'm poor. I had to take it apart, and reseat the amplifier ICs as the tab was not making contact with the chassis for one of them. I also added thermal paste. This amp is underpowered for my car, and may need replacing. It gets a bit hot.
+
+Some other issues with this amplifier are that the output connectors can get pushed back, there is only one output connector option, and it must run on battery power, as a 12V 1A or 2A will not power it. Finally, there is a 6V DC bias on output. No output audio isolation, which means you get car noise.
+
+\subsection{AC Audio Coupling to Remove DC Noise from Auto}
+I had some fun with this one. Many videos on this in the video folder. I started with the speakers being directly fed by the amplifier. This worked, but there was some noise coming through. Cars are noisy, this is not surprising. I would've preferred the amplifier to isolate the outputs, but no luck... At this point, I considered two options to block DC and allow AC. 1) Use a transformer. 2) Use capacitors.\footnote{A third option would've been to use a second set of batteries, but that would be laborious.}
+
+\subsubsection{Ground Isolator}
+I had been given a Ground isolator, which was two small transformers on a pcb intended to pass audio from a car powered signal source into the car speakers. I tried this isolator on the output of the speakers, and while it worked, the volume was lower, and it was impractical. I knew as soon as I heard the volume, that the issue was an impedance matching problem. The transformers were too small. They were intended for signal sources, not amplifier outputs. Onto option \#2.
+\\
+
+\begin{center}
+\includegraphics[scale=0.35]{../pics/DSCN2610.JPG}
+\captionof{figure}{Ground Loop Isolator.}
+\end{center}
+\subsubsection{Capacitor Audio Coupling}
+My initial thoughts here were: ``Let's be careful and use non polarized caps''. I bought some 0.22uf and 0.022uf polyester film capacitors at Electronics Plus, the local radioshack replacement, and tried them. No sound. After adjusting the connectors on the amp (which were admittedly loose - it's easy to push them back on the amplifier if you are not careful) I found that the capacitors didn't work. One problem was evident in the oscope. I only used one capacitor on the + output of the speaker amp, but the Amp biases the signal 6 volts. So I needed two. After that was resolved, the signal came through on the output of the capacitor, as viewed on the scope, however there was no sound output. I tried the safe way. It's time to break some rules. 
+
+I grabbed some 1uf (electrolytic polarized) caps I had, and tried these. Again, no sound. Not giving up, I grabbed some 1000uf 'lytics, and tried once more. Now it worked.
+
+\subsubsection{Impedance / ESR of capacitors failing to pass enough power of signal}
+Capacitors are rated for impedance. Some data sheets also call this ESR, it appears after a quick look. It's either in there as impedance or ESR. It's not initially an issue if you are using the capacitor as a DC reservoir, but if you use it in an AC coupling situation then things get interesting. A high impedance, or ESR will block what a low one won't. In this example, it's as simple as the Amplfier either being able to power a speaker or not. Higher capacity caps will have lower impedance. See the picture. Other brands put impedance in a graph, or just call it impedance. 
+
+\includegraphics[scale=0.5]{../pics/esr_impedance_capacitance.png}
+\captionof{figure}{Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.}
+
+\subsubsection{Wikipedia on Impedance}
+
+\emph{In general, a capacitor is seen as a storage component for electric energy. But this is only one capacitor function. A capacitor can also act as an AC resistor. Especially aluminum electrolytic capacitors are used in many applications as a decoupling capacitors to filter or bypass undesired biased AC frequencies to the ground or for capacitive coupling of audio AC signals. Then the dielectric is used only for blocking DC. For such applications the AC resistance, the impedance is as important as the capacitance value. }
+\begin{verbatim} https://en.wikipedia.org/w/index.php\title=Aluminum_electrolytic
+_capacitor&oldid=940281525
+\end{verbatim}
+Essentially, what I learned today.
+
+\subsection{DIY Amp}
+I was flipping through Practical Electronics for Inventors\cite{Scherz}(page 959), when I came across an audio amplifier. He also gives one at the chapter on Semiconductors (pg. 467), although the former is more detailed. With a reasonably simple schematic available, and a high likelihood of it working, I say why not: let's build it up.
+
+I've noticed that the ``Lvpin LP-838'' amplifier I'm using is underpowered for my two front speakers \footnote{Although it seems it would work for one channel, so two of them might be enough. It's rated for 20W, so that is about 15-20W per channel req'd. It works at 20W for both, just that it heats up too much. Multiple ebay sellers have it misquoted at 200W. Just an extra 0, no biggie. Based on all this, it appears each channel of my car speaker needs about 15 watts to be on the safe side. The example schematic is 16 watts. Two should suffice.}, so I will make two of the provided 16 watt amps.
+
+\subsubsection{LM383 is Obsolete}
+That explains why I haven't heard of it. The chip is obsolete. Some sell it on ebay for about \$5 each.
+
+As a different route, could I use some other power amplifier op amp, with the same pinout? Hm... Aha, the LM1875 has the same pinout. Let's use that.\footnote{How did I find this? I searched Digikey for the LM383 sold by rochester, noted it was it the category of Linear - Amplifiers - Audio, chose that, then searched for everything in the same package (TO220-5). Came right up. If this hadn't worked, I would've wanted to try other sites: Farnells, Mouser, etc...}
+
+Will it work with the same schematic? Questionable. May still need to buy a LM383, along with the LM1875, as backup. I might also try a generic power op amp.
+
+Amplfiers are the expensive bom item here.
+
+\subsection{Noise remains with Speaker Isolation}
+I've isolated the speakers from DC with the caps, but noise remains. My next idea was a DC-DC isolated supply. But, I found two threads on eevblog forums\cite{eevblog}, and they recommend a power line filter (they also mention the isolated supply). A filter with a coil and cap (2200uf even low enough) I can quickly build up.
+
+I also want to fix up my portable CRO, I obtained the other day. That needs batteries.
+
+One thing I noticed, is that the amplifier seems to no longer heat up, since the caps were added. Perhaps the DC bias was the cause. I need to confirm this.
+
+I was able to pull an 16.5V transformer from industrial equipment, so let's try this filter:
+
+\begin{center}
+\includegraphics[scale=0.75]{../pics/LC_Filter.png}
+\captionof{figure}{This picture was more difficult to download than it should've been. Spent 3 minutes on this. At least its not a discourse javascript pile of trash.} 
+ \end{center}
+
+\subsection{References}
+\begin{thebibliography}{99}
+\bibitem{Scherz}
+  Paul Scherz, and Simon Monk,
+  \emph{Practical Electronics for Inventors}, fourth edition - 2016, McGraw Hill.
+
+\bibitem{eevblog}
+  Various, \emph{https://www.eevblog.com/forum/projects/dreaded-alternator-whine-in-car-stereo/25/} Retrieved 2020-02-21. see also https://www.eevblog.com/forum/beginners/car-engine-signal-interference-with-cell-phone/
+
+\bibitem{partofthe}
+  \emph{https://partofthething.com/thoughts/building-a-low-pass-filter-to-remove-alternator-whine-in-my-car/}. Picture guide and showing basic build in project box. Eevblog users mention you may be able to use the secondary of a transformer, to avoid building the coil.
+  \end{thebibliography}
+
+\end{document}

Car_Stereo_Replacement/docs/23.tex~

@@ -0,0 +1,132 @@
+\documentclass[11pt]{article}
+%Gummi|065|=)
+\title{\textbf{Car Stereo Replacement}}
+\usepackage{graphicx,caption}
+%\author{Steak Electronics}
+\date{02/13/20}
+\begin{document}
+
+\maketitle
+%\tableofcontents
+
+\section{Car Stereo Replacement}
+Replacing a car stereo. I could just go to ebay, and buy a used car stereo, but where's the fun in that? Let's DIY a car stereo from a PCB used as a frontplate, a connector for my vehicle, and an audio amplifier. I'll connect in signal from an audio player.
+\\
+
+\includegraphics[scale=0.4]{../pics/DSCN2180.JPG}
+\captionof{figure}{PCB rev 1}
+
+\subsection{Items Included}
+I thought I would include the following:
+\begin{itemize}
+\item Arduino Nano
+\item Voltage and Gnd Breakout
+\item I2C Display
+\item Voltage Readout (of BAT)
+\item Current Readout (being drawn)
+\item Amplifier ``Lvpin LP-838''
+\end{itemize}
+I also wanted to have the connectors that eurorack and synth designers use for mono audio cables, but the cables turned out too expensive. The current readout didn't work initially, and I haven't gotten to fixing it yet.
+\subsubsection{I2C OLED display}
+Just for fun, I bought an I2C oled display and am going to use it to display something.\footnote{It's an Arduino Uno, you can put almost anything on this.} Notes on this:
+Using the adafruit SSD1306 and GFX library (this procedure is well covered in other places), you can load an example sketch and get it running. First thing to change is to remove the Adafruit logo and replace it with my own. Let's do that.
+
+From https://design.goeszen.com/convert-image-for-oled-display.html
+\begin{verbatim}
+I'm on Linux here and found that the readily-available 
+ImageMagick package will do the trick for you without
+ any scripting. And runs on the CLI! Simple as that:
+
+    convert some_image.png some.image.mono
+\end{verbatim}
+That's efficient. But it didn't really work out. Too much work, I don't need it that bad. Have to convert it to something the c compiler can read. I instead, just deleted their logo. Good enough for now.
+\subsubsection{Internal AVR Temperature Sensor}
+
+I setup the code to read from the internal temp sensor on the duino. However there is also this:
+
+https://thecavepearlproject.org/2019/02/25/no-parts-temperature-measurement-with-arduino-pro-mini-to-0-005c-or-better/
+
+This would be something to do for more resolution. The built in sensor is not very good, so this above link would be great. Hack a day also covers it. 
+
+\subsection{Wiring Pinout is wrong on Internet - Cable has labels}
+I looked at the picture I have detailing the pinout of my car connector (Delco Delphi radio wiring diagram.jpg in resources). It's close, but not 100\% correct. I found that the cable itself has small text labels on each wire which explain which everything does. I didn't notice earlier, as I didn't look close enough (and no one mentioned this).
+
+\subsection{Arduino VReg Blowout}
+I had a knock off Arduino Nano, and the vreg blew out. I have some other vregs to replace it. I didn't have this problem with an Uno that I use as a ceiling dome light. Although that one is not left on as long, usually. 
+
+\subsection{Amplifier}
+The amplifier I used is one of the cheapest avialable on ebay. I'm not proud. I'm poor. I had to take it apart, and reseat the amplifier ICs as the tab was not making contact with the chassis for one of them. I also added thermal paste. This amp is underpowered for my car, and may need replacing. It gets a bit hot.
+
+Some other issues with this amplifier are that the output connectors can get pushed back, there is only one output connector option, and it must run on battery power, as a 12V 1A or 2A will not power it. Finally, there is a 6V DC bias on output. No output audio isolation, which means you get car noise.
+
+\subsection{AC Audio Coupling to Remove DC Noise from Auto}
+I had some fun with this one. Many videos on this in the video folder. I started with the speakers being directly fed by the amplifier. This worked, but there was some noise coming through. Cars are noisy, this is not surprising. I would've preferred the amplifier to isolate the outputs, but no luck... At this point, I considered two options to block DC and allow AC. 1) Use a transformer. 2) Use capacitors.\footnote{A third option would've been to use a second set of batteries, but that would be laborious.}
+
+\subsubsection{Ground Isolator}
+I had been given a Ground isolator, which was two small transformers on a pcb intended to pass audio from a car powered signal source into the car speakers. I tried this isolator on the output of the speakers, and while it worked, the volume was lower, and it was impractical. I knew as soon as I heard the volume, that the issue was an impedance matching problem. The transformers were too small. They were intended for signal sources, not amplifier outputs. Onto option \#2.
+\\
+
+\begin{center}
+\includegraphics[scale=0.35]{../pics/DSCN2610.JPG}
+\captionof{figure}{Ground Loop Isolator.}
+\end{center}
+\subsubsection{Capacitor Audio Coupling}
+My initial thoughts here were: ``Let's be careful and use non polarized caps''. I bought some 0.22uf and 0.022uf polyester film capacitors at Electronics Plus, the local radioshack replacement, and tried them. No sound. After adjusting the connectors on the amp (which were admittedly loose - it's easy to push them back on the amplifier if you are not careful) I found that the capacitors didn't work. One problem was evident in the oscope. I only used one capacitor on the + output of the speaker amp, but the Amp biases the signal 6 volts. So I needed two. After that was resolved, the signal came through on the output of the capacitor, as viewed on the scope, however there was no sound output. I tried the safe way. It's time to break some rules. 
+
+I grabbed some 1uf (electrolytic polarized) caps I had, and tried these. Again, no sound. Not giving up, I grabbed some 1000uf 'lytics, and tried once more. Now it worked.
+
+\subsubsection{Impedance / ESR of capacitors failing to pass enough power of signal}
+Capacitors are rated for impedance. Some data sheets also call this ESR, it appears after a quick look. It's either in there as impedance or ESR. It's not initially an issue if you are using the capacitor as a DC reservoir, but if you use it in an AC coupling situation then things get interesting. A high impedance, or ESR will block what a low one won't. In this example, it's as simple as the Amplfier either being able to power a speaker or not. Higher capacity caps will have lower impedance. See the picture. Other brands put impedance in a graph, or just call it impedance. 
+
+\includegraphics[scale=0.5]{../pics/esr_impedance_capacitance.png}
+\captionof{figure}{Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.}
+
+\subsubsection{Wikipedia on Impedance}
+
+\emph{In general, a capacitor is seen as a storage component for electric energy. But this is only one capacitor function. A capacitor can also act as an AC resistor. Especially aluminum electrolytic capacitors are used in many applications as a decoupling capacitors to filter or bypass undesired biased AC frequencies to the ground or for capacitive coupling of audio AC signals. Then the dielectric is used only for blocking DC. For such applications the AC resistance, the impedance is as important as the capacitance value. }
+\begin{verbatim} https://en.wikipedia.org/w/index.php\title=Aluminum_electrolytic
+_capacitor&oldid=940281525
+\end{verbatim}
+Essentially, what I learned today.
+
+\subsection{DIY Amp}
+I was flipping through Practical Electronics for Inventors\cite{Scherz}(page 959), when I came across an audio amplifier. He also gives one at the chapter on Semiconductors (pg. 467), although the former is more detailed. With a reasonably simple schematic available, and a high likelihood of it working, I say why not: let's build it up.
+
+I've noticed that the ``Lvpin LP-838'' amplifier I'm using is underpowered for my two front speakers \footnote{Although it seems it would work for one channel, so two of them might be enough. It's rated for 20W, so that is about 15-20W per channel req'd. It works at 20W for both, just that it heats up too much. Multiple ebay sellers have it misquoted at 200W. Just an extra 0, no biggie. Based on all this, it appears each channel of my car speaker needs about 15 watts to be on the safe side. The example schematic is 16 watts. Two should suffice.}, so I will make two of the provided 16 watt amps.
+
+\subsubsection{LM383 is Obsolete}
+That explains why I haven't heard of it. The chip is obsolete. Some sell it on ebay for about \$5 each.
+
+As a different route, could I use some other power amplifier op amp, with the same pinout? Hm... Aha, the LM1875 has the same pinout. Let's use that.\footnote{How did I find this? I searched Digikey for the LM383 sold by rochester, noted it was it the category of Linear - Amplifiers - Audio, chose that, then searched for everything in the same package (TO220-5). Came right up. If this hadn't worked, I would've wanted to try other sites: Farnells, Mouser, etc...}
+
+Will it work with the same schematic? Questionable. May still need to buy a LM383, along with the LM1875, as backup. I might also try a generic power op amp.
+
+Amplfiers are the expensive bom item here.
+
+\subsection{Noise remains with Speaker Isolation}
+I've isolated the speakers from DC with the caps, but noise remains. My next idea was a DC-DC isolated supply. But, I found two threads on eevblog forums\cite{eevblog}, and they recommend a power line filter (they also mention the isolated supply). A filter with a coil and cap (2200uf even low enough) I can quickly build up.
+
+I also want to fix up my portable CRO, I obtained the other day. That needs batteries.
+
+One thing I noticed, is that the amplifier seems to no longer heat up, since the caps were added. Perhaps the DC bias was the cause. I need to confirm this.
+
+I was able to pull an 16.5V transformer from industrial equipment, so let's try this filter:
+
+\includegraphics[scale=0.5]{../pics/LC_Filter.png}
+\captionof{figure}{This picture was more difficult to download than it should've been. Spent 3 minutes on this.}
+ 
+
+\subsection{References}
+\begin{thebibliography}{99}
+\bibitem{Scherz}
+  Paul Scherz, and Simon Monk,
+  \emph{Practical Electronics for Inventors}, fourth edition - 2016, McGraw Hill.
+
+\bibitem{eevblog}
+  Various, \emph{https://www.eevblog.com/forum/projects/dreaded-alternator-whine-in-car-stereo/25/} Retrieved 2020-02-21. see also https://www.eevblog.com/forum/beginners/car-engine-signal-interference-with-cell-phone/
+
+\bibitem{partofthe}
+  \emph{https://partofthething.com/thoughts/building-a-low-pass-filter-to-remove-alternator-whine-in-my-car/}. Picture guide and showing basic build in project box. Eevblog users mention you may be able to use the secondary of a transformer, to avoid building the coil.
+  \end{thebibliography}
+
+\end{document}

Car_Stereo_Replacement/docs/24.aux

@@ -0,0 +1,28 @@
+\relax 
+\@writefile{toc}{\contentsline {section}{\numberline {1}Car Stereo Replacement}{1}}
+\@writefile{lof}{\contentsline {figure}{\numberline {1}{\ignorespaces PCB rev 1\relax }}{1}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.1}Items Included}{1}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.1.1}I2C OLED display}{2}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.1.2}Internal AVR Temperature Sensor}{2}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.2}Wiring Pinout is wrong on Internet - Cable has labels}{3}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.3}Arduino VReg Blowout}{3}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.4}Amplifier}{3}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.5}AC Audio Coupling to Remove DC Noise from Auto}{3}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.5.1}Ground Isolator}{4}}
+\@writefile{lof}{\contentsline {figure}{\numberline {2}{\ignorespaces Ground Loop Isolator.\relax }}{4}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.5.2}Capacitor Audio Coupling}{4}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.5.3}Impedance / ESR of capacitors failing to pass enough power of signal}{5}}
+\@writefile{lof}{\contentsline {figure}{\numberline {3}{\ignorespaces Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.\relax }}{5}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.5.4}Wikipedia on Impedance}{5}}
+\citation{Scherz}
+\citation{eevblog}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.6}DIY Amp}{6}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.6.1}LM383 is Obsolete}{6}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.7}Noise remains with Speaker Isolation}{7}}
+\@writefile{lof}{\contentsline {figure}{\numberline {4}{\ignorespaces This picture was more difficult to download than it should've been. Spent 3 minutes on this. At least its not a discourse javascript pile of trash.\relax }}{7}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.8}Low Pass Filter to remove Alternator Hum}{7}}
+\bibcite{Scherz}{1}
+\bibcite{eevblog}{2}
+\@writefile{lof}{\contentsline {figure}{\numberline {5}{\ignorespaces Fused supply from 12V car battery goes into the female barrel jack, into and out the secondary of the transformer leads. The primary is left floating. There is 2000uf 20\% 25V electrolytics after the inductor. Eliminates all alternator hum. Remember that as men, we are in the business of making tools. I have made it a goal to create perf board prototypes, and usable electronic devices, such as this LC filter. This is modular (via barrel plugs) and sturdy enough that I can use it to filter any power supply.\relax }}{8}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.9}References}{8}}
+\bibcite{partofthe}{3}

Car_Stereo_Replacement/docs/24.log

@@ -0,0 +1,300 @@
+This is pdfTeX, Version 3.14159265-2.6-1.40.17 (TeX Live 2016/Debian) (preloaded format=pdflatex 2019.8.17)  20 MAR 2020 22:23
+entering extended mode
+ restricted \write18 enabled.
+ %&-line parsing enabled.
+**/home/layoutdev/Desktop/code/documentation_general/Electronics_Projects_2019/
+Car_Stereo_Replacement/docs/24.tex
+
+(/home/layoutdev/Desktop/code/documentation_general/Electronics_Projects_2019/C
+ar_Stereo_Replacement/docs/24.tex
+LaTeX2e <2017/01/01> patch level 3
+Babel <3.9r> and hyphenation patterns for 3 language(s) loaded.
+(/usr/share/texlive/texmf-dist/tex/latex/base/article.cls
+Document Class: article 2014/09/29 v1.4h Standard LaTeX document class
+(/usr/share/texlive/texmf-dist/tex/latex/base/size11.clo
+File: size11.clo 2014/09/29 v1.4h Standard LaTeX file (size option)
+)
+\c@part=\count79
+\c@section=\count80
+\c@subsection=\count81
+\c@subsubsection=\count82
+\c@paragraph=\count83
+\c@subparagraph=\count84
+\c@figure=\count85
+\c@table=\count86
+\abovecaptionskip=\skip41
+\belowcaptionskip=\skip42
+\bibindent=\dimen102
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/graphicx.sty
+Package: graphicx 2014/10/28 v1.0g Enhanced LaTeX Graphics (DPC,SPQR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/keyval.sty
+Package: keyval 2014/10/28 v1.15 key=value parser (DPC)
+\KV@toks@=\toks14
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/graphics.sty
+Package: graphics 2016/10/09 v1.0u Standard LaTeX Graphics (DPC,SPQR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/trig.sty
+Package: trig 2016/01/03 v1.10 sin cos tan (DPC)
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics-cfg/graphics.cfg
+File: graphics.cfg 2016/06/04 v1.11 sample graphics configuration
+)
+Package graphics Info: Driver file: pdftex.def on input line 99.
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics-def/pdftex.def
+File: pdftex.def 2017/01/12 v0.06k Graphics/color for pdfTeX
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/infwarerr.sty
+Package: infwarerr 2016/05/16 v1.4 Providing info/warning/error messages (HO)
+)
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ltxcmds.sty
+Package: ltxcmds 2016/05/16 v1.23 LaTeX kernel commands for general use (HO)
+)
+\Gread@gobject=\count87
+))
+\Gin@req@height=\dimen103
+\Gin@req@width=\dimen104
+)
+(/usr/share/texlive/texmf-dist/tex/latex/caption/caption.sty
+Package: caption 2016/02/21 v3.3-144 Customizing captions (AR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/caption/caption3.sty
+Package: caption3 2016/05/22 v1.7-166 caption3 kernel (AR)
+Package caption3 Info: TeX engine: e-TeX on input line 67.
+\captionmargin=\dimen105
+\captionmargin@=\dimen106
+\captionwidth=\dimen107
+\caption@tempdima=\dimen108
+\caption@indent=\dimen109
+\caption@parindent=\dimen110
+\caption@hangindent=\dimen111
+)
+\c@ContinuedFloat=\count88
+) (./24.aux)
+\openout1 = `24.aux'.
+
+LaTeX Font Info:    Checking defaults for OML/cmm/m/it on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for T1/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OT1/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OMS/cmsy/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for OMX/cmex/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+LaTeX Font Info:    Checking defaults for U/cmr/m/n on input line 7.
+LaTeX Font Info:    ... okay on input line 7.
+
+(/usr/share/texlive/texmf-dist/tex/context/base/mkii/supp-pdf.mkii
+[Loading MPS to PDF converter (version 2006.09.02).]
+\scratchcounter=\count89
+\scratchdimen=\dimen112
+\scratchbox=\box26
+\nofMPsegments=\count90
+\nofMParguments=\count91
+\everyMPshowfont=\toks15
+\MPscratchCnt=\count92
+\MPscratchDim=\dimen113
+\MPnumerator=\count93
+\makeMPintoPDFobject=\count94
+\everyMPtoPDFconversion=\toks16
+) (/usr/share/texlive/texmf-dist/tex/generic/oberdiek/pdftexcmds.sty
+Package: pdftexcmds 2016/05/21 v0.22 Utility functions of pdfTeX for LuaTeX (HO
+)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ifluatex.sty
+Package: ifluatex 2016/05/16 v1.4 Provides the ifluatex switch (HO)
+Package ifluatex Info: LuaTeX not detected.
+)
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ifpdf.sty
+Package: ifpdf 2016/05/14 v3.1 Provides the ifpdf switch
+)
+Package pdftexcmds Info: LuaTeX not detected.
+Package pdftexcmds Info: \pdf@primitive is available.
+Package pdftexcmds Info: \pdf@ifprimitive is available.
+Package pdftexcmds Info: \pdfdraftmode found.
+)
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/epstopdf-base.sty
+Package: epstopdf-base 2016/05/15 v2.6 Base part for package epstopdf
+
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/grfext.sty
+Package: grfext 2016/05/16 v1.2 Manage graphics extensions (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/kvdefinekeys.sty
+Package: kvdefinekeys 2016/05/16 v1.4 Define keys (HO)
+))
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/kvoptions.sty
+Package: kvoptions 2016/05/16 v3.12 Key value format for package options (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/kvsetkeys.sty
+Package: kvsetkeys 2016/05/16 v1.17 Key value parser (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/etexcmds.sty
+Package: etexcmds 2016/05/16 v1.6 Avoid name clashes with e-TeX commands (HO)
+Package etexcmds Info: Could not find \expanded.
+(etexcmds)             That can mean that you are not using pdfTeX 1.50 or
+(etexcmds)             that some package has redefined \expanded.
+(etexcmds)             In the latter case, load this package earlier.
+)))
+Package epstopdf-base Info: Redefining graphics rule for `.eps' on input line 4
+38.
+Package grfext Info: Graphics extension search list:
+(grfext)             [.png,.pdf,.jpg,.mps,.jpeg,.jbig2,.jb2,.PNG,.PDF,.JPG,.JPE
+G,.JBIG2,.JB2,.eps]
+(grfext)             \AppendGraphicsExtensions on input line 456.
+
+(/usr/share/texlive/texmf-dist/tex/latex/latexconfig/epstopdf-sys.cfg
+File: epstopdf-sys.cfg 2010/07/13 v1.3 Configuration of (r)epstopdf for TeX Liv
+e
+))
+Package caption Info: Begin \AtBeginDocument code.
+Package caption Info: End \AtBeginDocument code.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <12> on input line 9.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <8> on input line 9.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <6> on input line 9.
+
+
+LaTeX Warning: No \author given.
+
+
+Underfull \hbox (badness 10000) in paragraph at lines 13--15
+
+ []
+
+<../pics/DSCN2180.JPG, id=1, 803.0pt x 602.25pt>
+File: ../pics/DSCN2180.JPG Graphic file (type jpg)
+ <use ../pics/DSCN2180.JPG>
+Package pdftex.def Info: ../pics/DSCN2180.JPG used on input line 16.
+(pdftex.def)             Requested size: 321.1943pt x 240.89572pt.
+
+
+Package caption Warning: \captionsetup{type*=...} or \captionof
+(caption)                outside box or environment on input line 17.
+See the caption package documentation for explanation.
+
+LaTeX Font Info:    Try loading font information for OMS+cmr on input line 22.
+(/usr/share/texlive/texmf-dist/tex/latex/base/omscmr.fd
+File: omscmr.fd 2014/09/29 v2.5h Standard LaTeX font definitions
+)
+LaTeX Font Info:    Font shape `OMS/cmr/m/n' in size <10.95> not available
+(Font)              Font shape `OMS/cmsy/m/n' tried instead on input line 22.
+ [1
+
+{/var/lib/texmf/fonts/map/pdftex/updmap/pdftex.map} <../pics/DSCN2180.JPG>]
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <10.95> on input line 31.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <9> on input line 31.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <5> on input line 31.
+
+Underfull \hbox (badness 10000) in paragraph at lines 47--48
+[]\OT1/cmr/m/n/10.95 https://thecavepearlproject.org/2019/02/25/no-parts-temper
+ature-
+ []
+
+[2]
+Underfull \hbox (badness 10000) in paragraph at lines 66--68
+
+ []
+
+[3] <../pics/DSCN2610.JPG, id=22, 803.0pt x 602.25pt>
+File: ../pics/DSCN2610.JPG Graphic file (type jpg)
+
+<use ../pics/DSCN2610.JPG>
+Package pdftex.def Info: ../pics/DSCN2610.JPG used on input line 70.
+(pdftex.def)             Requested size: 281.05421pt x 210.79065pt.
+ [4 <../pics/DSCN2610.JPG>]
+<../pics/esr_impedance_capacitance.png, id=26, 697.10437pt x 421.69917pt>
+File: ../pics/esr_impedance_capacitance.png Graphic file (type png)
+
+<use ../pics/esr_impedance_capacitance.png>
+Package pdftex.def Info: ../pics/esr_impedance_capacitance.png used on input li
+ne 81.
+(pdftex.def)             Requested size: 348.55133pt x 210.84906pt.
+ [5 <../pics/esr_impedance_capacitance.png (PNG copy)>]
+Overfull \hbox (13.6647pt too wide) in paragraph at lines 89--89
+[] \OT1/cmtt/m/n/10.95 https://en.wikipedia.org/w/index.php\title=Aluminum_elec
+trolytic 
+ []
+
+[6] <../pics/LC_Filter.png, id=34, 589.4522pt x 206.27063pt>
+File: ../pics/LC_Filter.png Graphic file (type png)
+
+<use ../pics/LC_Filter.png>
+Package pdftex.def Info: ../pics/LC_Filter.png used on input line 116.
+(pdftex.def)             Requested size: 442.08806pt x 154.70258pt.
+
+Overfull \hbox (82.08806pt too wide) in paragraph at lines 116--117
+ [] 
+ []
+
+[7 <../pics/LC_Filter.png>]
+<../pics/DSCN2845.JPG, id=41, 1003.75pt x 752.8125pt>
+File: ../pics/DSCN2845.JPG Graphic file (type jpg)
+
+<use ../pics/DSCN2845.JPG>
+Package pdftex.def Info: ../pics/DSCN2845.JPG used on input line 126.
+(pdftex.def)             Requested size: 401.49289pt x 301.11966pt.
+
+Overfull \hbox (41.49289pt too wide) in paragraph at lines 126--127
+ [] 
+ []
+
+
+Underfull \hbox (badness 10000) in paragraph at lines 139--140
+[]\OT1/cmr/m/n/10.95 Various, \OT1/cmr/m/it/10.95 https://www.eevblog.com/forum
+/projects/dreaded-
+ []
+
+
+Underfull \hbox (badness 10000) in paragraph at lines 139--140
+\OT1/cmr/m/it/10.95 alternator-whine-in-car-stereo/25/ \OT1/cmr/m/n/10.95 Re-tr
+ieved 2020-02-21. see
+ []
+
+
+Underfull \hbox (badness 10000) in paragraph at lines 139--140
+\OT1/cmr/m/n/10.95 also https://www.eevblog.com/forum/beginners/car-engine-sign
+al-
+ []
+
+[8 <../pics/DSCN2845.JPG>]
+Underfull \hbox (badness 10000) in paragraph at lines 142--143
+[]\OT1/cmr/m/it/10.95 https://partofthething.com/thoughts/building-a-low-pass-f
+ilter-to-
+ []
+
+[9] (./24.aux) ) 
+Here is how much of TeX's memory you used:
+ 2627 strings out of 494945
+ 42135 string characters out of 6181032
+ 96839 words of memory out of 5000000
+ 5909 multiletter control sequences out of 15000+600000
+ 10544 words of font info for 37 fonts, out of 8000000 for 9000
+ 14 hyphenation exceptions out of 8191
+ 39i,8n,39p,867b,211s stack positions out of 5000i,500n,10000p,200000b,80000s
+</usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/c
+mbx10.pfb></usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmbx12.
+pfb></usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmr10.pfb></u
+sr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmr12.pfb></usr/shar
+e/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmr6.pfb></usr/share/texliv
+e/texmf-dist/fonts/type1/public/amsfonts/cm/cmr8.pfb></usr/share/texlive/texmf-
+dist/fonts/type1/public/amsfonts/cm/cmr9.pfb></usr/share/texlive/texmf-dist/fon
+ts/type1/public/amsfonts/cm/cmsy10.pfb></usr/share/texlive/texmf-dist/fonts/typ
+e1/public/amsfonts/cm/cmti10.pfb></usr/share/texlive/texmf-dist/fonts/type1/pub
+lic/amsfonts/cm/cmtt10.pfb>
+Output written on 24.pdf (9 pages, 789642 bytes).
+PDF statistics:
+ 81 PDF objects out of 1000 (max. 8388607)
+ 53 compressed objects within 1 object stream
+ 0 named destinations out of 1000 (max. 500000)
+ 26 words of extra memory for PDF output out of 10000 (max. 10000000)
+

Car_Stereo_Replacement/docs/24.tex

@@ -0,0 +1,145 @@
+\documentclass[11pt]{article}
+%Gummi|065|=)
+\title{\textbf{Car Stereo Replacement}}
+\usepackage{graphicx,caption}
+%\author{Steak Electronics}
+\date{02/13/20}
+\begin{document}
+
+\maketitle
+%\tableofcontents
+
+\section{Car Stereo Replacement}
+Replacing a car stereo. I could just go to ebay, and buy a used car stereo, but where's the fun in that? Let's DIY a car stereo from a PCB used as a frontplate, a connector for my vehicle, and an audio amplifier. I'll connect in signal from an audio player.
+\\
+
+\includegraphics[scale=0.4]{../pics/DSCN2180.JPG}
+\captionof{figure}{PCB rev 1}
+
+\subsection{Items Included}
+I thought I would include the following:
+\begin{itemize}
+\item Arduino Nano
+\item Voltage and Gnd Breakout
+\item I2C Display
+\item Voltage Readout (of BAT)
+\item Current Readout (being drawn)
+\item Amplifier ``Lvpin LP-838''
+\end{itemize}
+I also wanted to have the connectors that eurorack and synth designers use for mono audio cables, but the cables turned out too expensive. The current readout didn't work initially, and I haven't gotten to fixing it yet.
+\subsubsection{I2C OLED display}
+Just for fun, I bought an I2C oled display and am going to use it to display something.\footnote{It's an Arduino Uno, you can put almost anything on this.} Notes on this:
+Using the adafruit SSD1306 and GFX library (this procedure is well covered in other places), you can load an example sketch and get it running. First thing to change is to remove the Adafruit logo and replace it with my own. Let's do that.
+
+From https://design.goeszen.com/convert-image-for-oled-display.html
+\begin{verbatim}
+I'm on Linux here and found that the readily-available 
+ImageMagick package will do the trick for you without
+ any scripting. And runs on the CLI! Simple as that:
+
+    convert some_image.png some.image.mono
+\end{verbatim}
+That's efficient. But it didn't really work out. Too much work, I don't need it that bad. Have to convert it to something the c compiler can read. I instead, just deleted their logo. Good enough for now.
+\subsubsection{Internal AVR Temperature Sensor}
+
+I setup the code to read from the internal temp sensor on the duino. However there is also this:
+
+https://thecavepearlproject.org/2019/02/25/no-parts-temperature-measurement-with-arduino-pro-mini-to-0-005c-or-better/
+
+This would be something to do for more resolution. The built in sensor is not very good, so this above link would be great. Hack a day also covers it. 
+
+\subsection{Wiring Pinout is wrong on Internet - Cable has labels}
+I looked at the picture I have detailing the pinout of my car connector (Delco Delphi radio wiring diagram.jpg in resources). It's close, but not 100\% correct. I found that the cable itself has small text labels on each wire which explain which everything does. I didn't notice earlier, as I didn't look close enough (and no one mentioned this).
+
+\subsection{Arduino VReg Blowout}
+I had a knock off Arduino Nano, and the vreg blew out. I have some other vregs to replace it. I didn't have this problem with an Uno that I use as a ceiling dome light. Although that one is not left on as long, usually. 
+
+\subsection{Amplifier}
+The amplifier I used is one of the cheapest avialable on ebay. I'm not proud. I'm poor. I had to take it apart, and reseat the amplifier ICs as the tab was not making contact with the chassis for one of them. I also added thermal paste. This amp is underpowered for my car, and may need replacing. It gets a bit hot.
+
+Some other issues with this amplifier are that the output connectors can get pushed back, there is only one output connector option, and it must run on battery power, as a 12V 1A or 2A will not power it. Finally, there is a 6V DC bias on output. No output audio isolation, which means you get car noise.
+
+\subsection{AC Audio Coupling to Remove DC Noise from Auto}
+I had some fun with this one. Many videos on this in the video folder. I started with the speakers being directly fed by the amplifier. This worked, but there was some noise coming through. Cars are noisy, this is not surprising. I would've preferred the amplifier to isolate the outputs, but no luck... At this point, I considered two options to block DC and allow AC. 1) Use a transformer. 2) Use capacitors.\footnote{A third option would've been to use a second set of batteries, but that would be laborious.}
+
+\subsubsection{Ground Isolator}
+I had been given a Ground isolator, which was two small transformers on a pcb intended to pass audio from a car powered signal source into the car speakers. I tried this isolator on the output of the speakers, and while it worked, the volume was lower, and it was impractical. I knew as soon as I heard the volume, that the issue was an impedance matching problem. The transformers were too small. They were intended for signal sources, not amplifier outputs. Onto option \#2.
+\\
+
+\begin{center}
+\includegraphics[scale=0.35]{../pics/DSCN2610.JPG}
+\captionof{figure}{Ground Loop Isolator.}
+\end{center}
+\subsubsection{Capacitor Audio Coupling}
+My initial thoughts here were: ``Let's be careful and use non polarized caps''. I bought some 0.22uf and 0.022uf polyester film capacitors at Electronics Plus, the local radioshack replacement, and tried them. No sound. After adjusting the connectors on the amp (which were admittedly loose - it's easy to push them back on the amplifier if you are not careful) I found that the capacitors didn't work. One problem was evident in the oscope. I only used one capacitor on the + output of the speaker amp, but the Amp biases the signal 6 volts. So I needed two. After that was resolved, the signal came through on the output of the capacitor, as viewed on the scope, however there was no sound output. I tried the safe way. It's time to break some rules. 
+
+I grabbed some 1uf (electrolytic polarized) caps I had, and tried these. Again, no sound. Not giving up, I grabbed some 1000uf 'lytics, and tried once more. Now it worked.
+
+\subsubsection{Impedance / ESR of capacitors failing to pass enough power of signal}
+Capacitors are rated for impedance. Some data sheets also call this ESR, it appears after a quick look. It's either in there as impedance or ESR. It's not initially an issue if you are using the capacitor as a DC reservoir, but if you use it in an AC coupling situation then things get interesting. A high impedance, or ESR will block what a low one won't. In this example, it's as simple as the Amplfier either being able to power a speaker or not. Higher capacity caps will have lower impedance. See the picture. Other brands put impedance in a graph, or just call it impedance. 
+
+\includegraphics[scale=0.5]{../pics/esr_impedance_capacitance.png}
+\captionof{figure}{Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.}
+
+\subsubsection{Wikipedia on Impedance}
+
+\emph{In general, a capacitor is seen as a storage component for electric energy. But this is only one capacitor function. A capacitor can also act as an AC resistor. Especially aluminum electrolytic capacitors are used in many applications as a decoupling capacitors to filter or bypass undesired biased AC frequencies to the ground or for capacitive coupling of audio AC signals. Then the dielectric is used only for blocking DC. For such applications the AC resistance, the impedance is as important as the capacitance value. }
+\begin{verbatim} https://en.wikipedia.org/w/index.php\title=Aluminum_electrolytic
+_capacitor&oldid=940281525
+\end{verbatim}
+Essentially, what I learned today.
+
+\subsection{DIY Amp}
+I was flipping through Practical Electronics for Inventors\cite{Scherz}(page 959), when I came across an audio amplifier. He also gives one at the chapter on Semiconductors (pg. 467), although the former is more detailed. With a reasonably simple schematic available, and a high likelihood of it working, I say why not: let's build it up.
+
+I've noticed that the ``Lvpin LP-838'' amplifier I'm using is underpowered for my two front speakers \footnote{Although it seems it would work for one channel, so two of them might be enough. It's rated for 20W, so that is about 15-20W per channel req'd. It works at 20W for both, just that it heats up too much. Multiple ebay sellers have it misquoted at 200W. Just an extra 0, no biggie. Based on all this, it appears each channel of my car speaker needs about 15 watts to be on the safe side. The example schematic is 16 watts. Two should suffice.}, so I will make two of the provided 16 watt amps.
+
+\subsubsection{LM383 is Obsolete}
+That explains why I haven't heard of it. The chip is obsolete. Some sell it on ebay for about \$5 each.
+
+As a different route, could I use some other power amplifier op amp, with the same pinout? Hm... Aha, the LM1875 has the same pinout. Let's use that.\footnote{How did I find this? I searched Digikey for the LM383 sold by rochester, noted it was it the category of Linear - Amplifiers - Audio, chose that, then searched for everything in the same package (TO220-5). Came right up. If this hadn't worked, I would've wanted to try other sites: Farnells, Mouser, etc...}
+
+Will it work with the same schematic? Questionable. May still need to buy a LM383, along with the LM1875, as backup. I might also try a generic power op amp.
+
+Amplfiers are the expensive bom item here.
+
+\subsection{Noise remains with Speaker Isolation}
+I've isolated the speakers from DC with the caps, but noise remains. My next idea was a DC-DC isolated supply. But, I found two threads on eevblog forums\cite{eevblog}, and they recommend a power line filter (they also mention the isolated supply). A filter with a coil and cap (2200uf even low enough) I can quickly build up.
+
+I also want to fix up my portable CRO, I obtained the other day. That needs batteries.
+
+One thing I noticed, is that the amplifier seems to no longer heat up, since the caps were added. Perhaps the DC bias was the cause. I need to confirm this.
+
+I was able to pull an 16.5V transformer from industrial equipment, so let's try this filter:
+
+\begin{center}
+\includegraphics[scale=0.75]{../pics/LC_Filter.png}
+\captionof{figure}{This picture was more difficult to download than it should've been. Spent 3 minutes on this. At least its not a discourse javascript pile of trash.} 
+\end{center}
+
+\subsection{Low Pass Filter to remove Alternator Hum}
+I have built the Low Pass Filter consisting of a 120 to 16V AC transformer and a 2200uf Cap (LC filter). I tested it on my signal gen, and it works quite well. No AC ripple comes through. I tested it in the car, and success - there is no more alternator hum. However...
+
+There is still some noise on the speakers. It is not audible. I can't hear it, but I can feel my ears get sensitive after listening for a song or two. There must be something else getting through that is causing my ears to become sensitive. Either that, or I was not in the mood to listen to my stereo. See the picture of the filter below.
+
+\begin{center}
+\includegraphics[scale=0.4]{../pics/DSCN2845.JPG}
+\captionof{figure}{Fused supply from 12V car battery goes into the female barrel jack, into and out the secondary of the transformer leads. The primary is left floating. There is 2000uf 20\% 25V electrolytics after the inductor. Eliminates all alternator hum. Remember that as men, we are in the business of making tools. I have made it a goal to create perf board prototypes, and usable electronic devices, such as this LC filter. This is modular (via barrel plugs) and sturdy enough that I can use it to filter any power supply.}
+\end{center}
+
+
+
+\subsection{References}
+\begin{thebibliography}{99}
+\bibitem{Scherz}
+  Paul Scherz, and Simon Monk,
+  \emph{Practical Electronics for Inventors}, fourth edition - 2016, McGraw Hill.
+
+\bibitem{eevblog}
+  Various, \emph{https://www.eevblog.com/forum/projects/dreaded-alternator-whine-in-car-stereo/25/} Retrieved 2020-02-21. see also https://www.eevblog.com/forum/beginners/car-engine-signal-interference-with-cell-phone/
+
+\bibitem{partofthe}
+  \emph{https://partofthething.com/thoughts/building-a-low-pass-filter-to-remove-alternator-whine-in-my-car/}. Picture guide and showing basic build in project box. Eevblog users mention you may be able to use the secondary of a transformer, to avoid building the coil.
+  \end{thebibliography}
+
+\end{document}

Car_Stereo_Replacement/docs/24.tex~

@@ -0,0 +1,143 @@
+\documentclass[11pt]{article}
+%Gummi|065|=)
+\title{\textbf{Car Stereo Replacement}}
+\usepackage{graphicx,caption}
+%\author{Steak Electronics}
+\date{02/13/20}
+\begin{document}
+
+\maketitle
+%\tableofcontents
+
+\section{Car Stereo Replacement}
+Replacing a car stereo. I could just go to ebay, and buy a used car stereo, but where's the fun in that? Let's DIY a car stereo from a PCB used as a frontplate, a connector for my vehicle, and an audio amplifier. I'll connect in signal from an audio player.
+\\
+
+\includegraphics[scale=0.4]{../pics/DSCN2180.JPG}
+\captionof{figure}{PCB rev 1}
+
+\subsection{Items Included}
+I thought I would include the following:
+\begin{itemize}
+\item Arduino Nano
+\item Voltage and Gnd Breakout
+\item I2C Display
+\item Voltage Readout (of BAT)
+\item Current Readout (being drawn)
+\item Amplifier ``Lvpin LP-838''
+\end{itemize}
+I also wanted to have the connectors that eurorack and synth designers use for mono audio cables, but the cables turned out too expensive. The current readout didn't work initially, and I haven't gotten to fixing it yet.
+\subsubsection{I2C OLED display}
+Just for fun, I bought an I2C oled display and am going to use it to display something.\footnote{It's an Arduino Uno, you can put almost anything on this.} Notes on this:
+Using the adafruit SSD1306 and GFX library (this procedure is well covered in other places), you can load an example sketch and get it running. First thing to change is to remove the Adafruit logo and replace it with my own. Let's do that.
+
+From https://design.goeszen.com/convert-image-for-oled-display.html
+\begin{verbatim}
+I'm on Linux here and found that the readily-available 
+ImageMagick package will do the trick for you without
+ any scripting. And runs on the CLI! Simple as that:
+
+    convert some_image.png some.image.mono
+\end{verbatim}
+That's efficient. But it didn't really work out. Too much work, I don't need it that bad. Have to convert it to something the c compiler can read. I instead, just deleted their logo. Good enough for now.
+\subsubsection{Internal AVR Temperature Sensor}
+
+I setup the code to read from the internal temp sensor on the duino. However there is also this:
+
+https://thecavepearlproject.org/2019/02/25/no-parts-temperature-measurement-with-arduino-pro-mini-to-0-005c-or-better/
+
+This would be something to do for more resolution. The built in sensor is not very good, so this above link would be great. Hack a day also covers it. 
+
+\subsection{Wiring Pinout is wrong on Internet - Cable has labels}
+I looked at the picture I have detailing the pinout of my car connector (Delco Delphi radio wiring diagram.jpg in resources). It's close, but not 100\% correct. I found that the cable itself has small text labels on each wire which explain which everything does. I didn't notice earlier, as I didn't look close enough (and no one mentioned this).
+
+\subsection{Arduino VReg Blowout}
+I had a knock off Arduino Nano, and the vreg blew out. I have some other vregs to replace it. I didn't have this problem with an Uno that I use as a ceiling dome light. Although that one is not left on as long, usually. 
+
+\subsection{Amplifier}
+The amplifier I used is one of the cheapest avialable on ebay. I'm not proud. I'm poor. I had to take it apart, and reseat the amplifier ICs as the tab was not making contact with the chassis for one of them. I also added thermal paste. This amp is underpowered for my car, and may need replacing. It gets a bit hot.
+
+Some other issues with this amplifier are that the output connectors can get pushed back, there is only one output connector option, and it must run on battery power, as a 12V 1A or 2A will not power it. Finally, there is a 6V DC bias on output. No output audio isolation, which means you get car noise.
+
+\subsection{AC Audio Coupling to Remove DC Noise from Auto}
+I had some fun with this one. Many videos on this in the video folder. I started with the speakers being directly fed by the amplifier. This worked, but there was some noise coming through. Cars are noisy, this is not surprising. I would've preferred the amplifier to isolate the outputs, but no luck... At this point, I considered two options to block DC and allow AC. 1) Use a transformer. 2) Use capacitors.\footnote{A third option would've been to use a second set of batteries, but that would be laborious.}
+
+\subsubsection{Ground Isolator}
+I had been given a Ground isolator, which was two small transformers on a pcb intended to pass audio from a car powered signal source into the car speakers. I tried this isolator on the output of the speakers, and while it worked, the volume was lower, and it was impractical. I knew as soon as I heard the volume, that the issue was an impedance matching problem. The transformers were too small. They were intended for signal sources, not amplifier outputs. Onto option \#2.
+\\
+
+\begin{center}
+\includegraphics[scale=0.35]{../pics/DSCN2610.JPG}
+\captionof{figure}{Ground Loop Isolator.}
+\end{center}
+\subsubsection{Capacitor Audio Coupling}
+My initial thoughts here were: ``Let's be careful and use non polarized caps''. I bought some 0.22uf and 0.022uf polyester film capacitors at Electronics Plus, the local radioshack replacement, and tried them. No sound. After adjusting the connectors on the amp (which were admittedly loose - it's easy to push them back on the amplifier if you are not careful) I found that the capacitors didn't work. One problem was evident in the oscope. I only used one capacitor on the + output of the speaker amp, but the Amp biases the signal 6 volts. So I needed two. After that was resolved, the signal came through on the output of the capacitor, as viewed on the scope, however there was no sound output. I tried the safe way. It's time to break some rules. 
+
+I grabbed some 1uf (electrolytic polarized) caps I had, and tried these. Again, no sound. Not giving up, I grabbed some 1000uf 'lytics, and tried once more. Now it worked.
+
+\subsubsection{Impedance / ESR of capacitors failing to pass enough power of signal}
+Capacitors are rated for impedance. Some data sheets also call this ESR, it appears after a quick look. It's either in there as impedance or ESR. It's not initially an issue if you are using the capacitor as a DC reservoir, but if you use it in an AC coupling situation then things get interesting. A high impedance, or ESR will block what a low one won't. In this example, it's as simple as the Amplfier either being able to power a speaker or not. Higher capacity caps will have lower impedance. See the picture. Other brands put impedance in a graph, or just call it impedance. 
+
+\includegraphics[scale=0.5]{../pics/esr_impedance_capacitance.png}
+\captionof{figure}{Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.}
+
+\subsubsection{Wikipedia on Impedance}
+
+\emph{In general, a capacitor is seen as a storage component for electric energy. But this is only one capacitor function. A capacitor can also act as an AC resistor. Especially aluminum electrolytic capacitors are used in many applications as a decoupling capacitors to filter or bypass undesired biased AC frequencies to the ground or for capacitive coupling of audio AC signals. Then the dielectric is used only for blocking DC. For such applications the AC resistance, the impedance is as important as the capacitance value. }
+\begin{verbatim} https://en.wikipedia.org/w/index.php\title=Aluminum_electrolytic
+_capacitor&oldid=940281525
+\end{verbatim}
+Essentially, what I learned today.
+
+\subsection{DIY Amp}
+I was flipping through Practical Electronics for Inventors\cite{Scherz}(page 959), when I came across an audio amplifier. He also gives one at the chapter on Semiconductors (pg. 467), although the former is more detailed. With a reasonably simple schematic available, and a high likelihood of it working, I say why not: let's build it up.
+
+I've noticed that the ``Lvpin LP-838'' amplifier I'm using is underpowered for my two front speakers \footnote{Although it seems it would work for one channel, so two of them might be enough. It's rated for 20W, so that is about 15-20W per channel req'd. It works at 20W for both, just that it heats up too much. Multiple ebay sellers have it misquoted at 200W. Just an extra 0, no biggie. Based on all this, it appears each channel of my car speaker needs about 15 watts to be on the safe side. The example schematic is 16 watts. Two should suffice.}, so I will make two of the provided 16 watt amps.
+
+\subsubsection{LM383 is Obsolete}
+That explains why I haven't heard of it. The chip is obsolete. Some sell it on ebay for about \$5 each.
+
+As a different route, could I use some other power amplifier op amp, with the same pinout? Hm... Aha, the LM1875 has the same pinout. Let's use that.\footnote{How did I find this? I searched Digikey for the LM383 sold by rochester, noted it was it the category of Linear - Amplifiers - Audio, chose that, then searched for everything in the same package (TO220-5). Came right up. If this hadn't worked, I would've wanted to try other sites: Farnells, Mouser, etc...}
+
+Will it work with the same schematic? Questionable. May still need to buy a LM383, along with the LM1875, as backup. I might also try a generic power op amp.
+
+Amplfiers are the expensive bom item here.
+
+\subsection{Noise remains with Speaker Isolation}
+I've isolated the speakers from DC with the caps, but noise remains. My next idea was a DC-DC isolated supply. But, I found two threads on eevblog forums\cite{eevblog}, and they recommend a power line filter (they also mention the isolated supply). A filter with a coil and cap (2200uf even low enough) I can quickly build up.
+
+I also want to fix up my portable CRO, I obtained the other day. That needs batteries.
+
+One thing I noticed, is that the amplifier seems to no longer heat up, since the caps were added. Perhaps the DC bias was the cause. I need to confirm this.
+
+I was able to pull an 16.5V transformer from industrial equipment, so let's try this filter:
+
+\begin{center}
+\includegraphics[scale=0.75]{../pics/LC_Filter.png}
+\captionof{figure}{This picture was more difficult to download than it should've been. Spent 3 minutes on this. At least its not a discourse javascript pile of trash.} 
+\end{center}
+
+\subsection{Low Pass Filter to remove Alternator Hum}
+I have built the Low Pass Filter consisting of a 120 to 16V AC transformer and a 2200uf Cap (LC filter). I tested it on my signal gen, and it works quite well. No AC ripple comes through. I tested it in the car, and success - there is no more alternator hum. However...
+
+There is still some noise on the speakers. It is not audible. I can't hear it, but I can feel my ears get sensitive after listening for a song or two. There must be something else getting through that is causing my ears to become sensitive. Either that, or I was not in the mood to listen to my stereo. See the picture of the filter below.
+
+\begin{center}
+\includegraphics[scale=0.75]{../pics/DSCN2845.JPG}
+\captionof{figure}{Fused supply from 12V car battery goes into the female barrel jack, into and out the secondary of the transformer leads. The primary is left floating. There is 2000uf 20\% 25V electrolytics after the inductor. Eliminates all alternator hum.}
+\end{center}
+
+\subsection{References}
+\begin{thebibliography}{99}
+\bibitem{Scherz}
+  Paul Scherz, and Simon Monk,
+  \emph{Practical Electronics for Inventors}, fourth edition - 2016, McGraw Hill.
+
+\bibitem{eevblog}
+  Various, \emph{https://www.eevblog.com/forum/projects/dreaded-alternator-whine-in-car-stereo/25/} Retrieved 2020-02-21. see also https://www.eevblog.com/forum/beginners/car-engine-signal-interference-with-cell-phone/
+
+\bibitem{partofthe}
+  \emph{https://partofthething.com/thoughts/building-a-low-pass-filter-to-remove-alternator-whine-in-my-car/}. Picture guide and showing basic build in project box. Eevblog users mention you may be able to use the secondary of a transformer, to avoid building the coil.
+  \end{thebibliography}
+
+\end{document}

Car_Stereo_Replacement/docs/25.aux

@@ -0,0 +1,29 @@
+\relax 
+\@writefile{toc}{\contentsline {section}{\numberline {1}Car Stereo Replacement}{1}}
+\@writefile{lof}{\contentsline {figure}{\numberline {1}{\ignorespaces PCB rev 1\relax }}{1}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.1}Items Included}{2}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.1.1}I2C OLED display}{2}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.1.2}Internal AVR Temperature Sensor}{3}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.2}Wiring Pinout is wrong on Internet - Cable has labels}{3}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.3}Arduino VReg Blowout}{3}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.4}Amplifier}{3}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.5}AC Audio Coupling to Remove DC Noise from Auto}{4}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.5.1}Ground Isolator}{4}}
+\@writefile{lof}{\contentsline {figure}{\numberline {2}{\ignorespaces Ground Loop Isolator.\relax }}{5}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.5.2}Capacitor Audio Coupling}{5}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.5.3}Impedance / ESR of capacitors failing to pass enough power of signal}{6}}
+\@writefile{lof}{\contentsline {figure}{\numberline {3}{\ignorespaces Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.\relax }}{6}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.5.4}Wikipedia on Impedance}{6}}
+\citation{Scherz}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.6}DIY Amp}{7}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.6.1}LM383 is Obsolete}{7}}
+\citation{eevblog}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.7}Noise remains with Speaker Isolation}{8}}
+\@writefile{lof}{\contentsline {figure}{\numberline {4}{\ignorespaces This picture was more difficult to download than it should've been. Spent 3 minutes on this. At least its not a discourse javascript pile of trash.\relax }}{8}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.8}Low Pass Filter to remove Alternator Hum}{9}}
+\@writefile{lof}{\contentsline {figure}{\numberline {5}{\ignorespaces Fused supply from 12V car battery goes into the female barrel jack, into and out the secondary of the transformer leads. The primary is left floating. There is 2000uf 20\% 25V electrolytics after the inductor. Eliminates all alternator hum. Remember that as men, we are in the business of making tools. I have made it a goal to create perf board prototypes, and usable electronic devices, such as this LC filter. This is modular (via barrel plugs) and sturdy enough that I can use it to filter any power supply.\relax }}{9}}
+\bibcite{Scherz}{1}
+\bibcite{eevblog}{2}
+\bibcite{partofthe}{3}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.9}The story so far}{10}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.10}References}{10}}

Car_Stereo_Replacement/docs/25.log

@@ -0,0 +1,389 @@
+This is pdfTeX, Version 3.14159265-2.6-1.40.17 (TeX Live 2016/Debian) (preloaded format=pdflatex 2019.8.17)  20 MAR 2020 22:35
+entering extended mode
+ restricted \write18 enabled.
+ %&-line parsing enabled.
+**/home/layoutdev/Desktop/code/documentation_general/Electronics_Projects_2019/
+Car_Stereo_Replacement/docs/25.tex
+
+(/home/layoutdev/Desktop/code/documentation_general/Electronics_Projects_2019/C
+ar_Stereo_Replacement/docs/25.tex
+LaTeX2e <2017/01/01> patch level 3
+Babel <3.9r> and hyphenation patterns for 3 language(s) loaded.
+(/usr/share/texlive/texmf-dist/tex/latex/base/article.cls
+Document Class: article 2014/09/29 v1.4h Standard LaTeX document class
+(/usr/share/texlive/texmf-dist/tex/latex/base/size11.clo
+File: size11.clo 2014/09/29 v1.4h Standard LaTeX file (size option)
+)
+\c@part=\count79
+\c@section=\count80
+\c@subsection=\count81
+\c@subsubsection=\count82
+\c@paragraph=\count83
+\c@subparagraph=\count84
+\c@figure=\count85
+\c@table=\count86
+\abovecaptionskip=\skip41
+\belowcaptionskip=\skip42
+\bibindent=\dimen102
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/graphicx.sty
+Package: graphicx 2014/10/28 v1.0g Enhanced LaTeX Graphics (DPC,SPQR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/keyval.sty
+Package: keyval 2014/10/28 v1.15 key=value parser (DPC)
+\KV@toks@=\toks14
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/graphics.sty
+Package: graphics 2016/10/09 v1.0u Standard LaTeX Graphics (DPC,SPQR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/trig.sty
+Package: trig 2016/01/03 v1.10 sin cos tan (DPC)
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics-cfg/graphics.cfg
+File: graphics.cfg 2016/06/04 v1.11 sample graphics configuration
+)
+Package graphics Info: Driver file: pdftex.def on input line 99.
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics-def/pdftex.def
+File: pdftex.def 2017/01/12 v0.06k Graphics/color for pdfTeX
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/infwarerr.sty
+Package: infwarerr 2016/05/16 v1.4 Providing info/warning/error messages (HO)
+)
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ltxcmds.sty
+Package: ltxcmds 2016/05/16 v1.23 LaTeX kernel commands for general use (HO)
+)
+\Gread@gobject=\count87
+))
+\Gin@req@height=\dimen103
+\Gin@req@width=\dimen104
+)
+(/usr/share/texlive/texmf-dist/tex/latex/caption/caption.sty
+Package: caption 2016/02/21 v3.3-144 Customizing captions (AR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/caption/caption3.sty
+Package: caption3 2016/05/22 v1.7-166 caption3 kernel (AR)
+Package caption3 Info: TeX engine: e-TeX on input line 67.
+\captionmargin=\dimen105
+\captionmargin@=\dimen106
+\captionwidth=\dimen107
+\caption@tempdima=\dimen108
+\caption@indent=\dimen109
+\caption@parindent=\dimen110
+\caption@hangindent=\dimen111
+)
+\c@ContinuedFloat=\count88
+)
+(/usr/share/texlive/texmf-dist/tex/latex/xcolor/xcolor.sty
+Package: xcolor 2016/05/11 v2.12 LaTeX color extensions (UK)
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics-cfg/color.cfg
+File: color.cfg 2016/01/02 v1.6 sample color configuration
+)
+Package xcolor Info: Driver file: pdftex.def on input line 225.
+Package xcolor Info: Model `cmy' substituted by `cmy0' on input line 1348.
+Package xcolor Info: Model `hsb' substituted by `rgb' on input line 1352.
+Package xcolor Info: Model `RGB' extended on input line 1364.
+Package xcolor Info: Model `HTML' substituted by `rgb' on input line 1366.
+Package xcolor Info: Model `Hsb' substituted by `hsb' on input line 1367.
+Package xcolor Info: Model `tHsb' substituted by `hsb' on input line 1368.
+Package xcolor Info: Model `HSB' substituted by `hsb' on input line 1369.
+Package xcolor Info: Model `Gray' substituted by `gray' on input line 1370.
+Package xcolor Info: Model `wave' substituted by `hsb' on input line 1371.
+)
+(/usr/share/texlive/texmf-dist/tex/latex/geometry/geometry.sty
+Package: geometry 2010/09/12 v5.6 Page Geometry
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ifpdf.sty
+Package: ifpdf 2016/05/14 v3.1 Provides the ifpdf switch
+)
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ifvtex.sty
+Package: ifvtex 2016/05/16 v1.6 Detect VTeX and its facilities (HO)
+Package ifvtex Info: VTeX not detected.
+)
+(/usr/share/texlive/texmf-dist/tex/generic/ifxetex/ifxetex.sty
+Package: ifxetex 2010/09/12 v0.6 Provides ifxetex conditional
+)
+\Gm@cnth=\count89
+\Gm@cntv=\count90
+\c@Gm@tempcnt=\count91
+\Gm@bindingoffset=\dimen112
+\Gm@wd@mp=\dimen113
+\Gm@odd@mp=\dimen114
+\Gm@even@mp=\dimen115
+\Gm@layoutwidth=\dimen116
+\Gm@layoutheight=\dimen117
+\Gm@layouthoffset=\dimen118
+\Gm@layoutvoffset=\dimen119
+\Gm@dimlist=\toks15
+) (./25.aux)
+\openout1 = `25.aux'.
+
+LaTeX Font Info:    Checking defaults for OML/cmm/m/it on input line 11.
+LaTeX Font Info:    ... okay on input line 11.
+LaTeX Font Info:    Checking defaults for T1/cmr/m/n on input line 11.
+LaTeX Font Info:    ... okay on input line 11.
+LaTeX Font Info:    Checking defaults for OT1/cmr/m/n on input line 11.
+LaTeX Font Info:    ... okay on input line 11.
+LaTeX Font Info:    Checking defaults for OMS/cmsy/m/n on input line 11.
+LaTeX Font Info:    ... okay on input line 11.
+LaTeX Font Info:    Checking defaults for OMX/cmex/m/n on input line 11.
+LaTeX Font Info:    ... okay on input line 11.
+LaTeX Font Info:    Checking defaults for U/cmr/m/n on input line 11.
+LaTeX Font Info:    ... okay on input line 11.
+
+(/usr/share/texlive/texmf-dist/tex/context/base/mkii/supp-pdf.mkii
+[Loading MPS to PDF converter (version 2006.09.02).]
+\scratchcounter=\count92
+\scratchdimen=\dimen120
+\scratchbox=\box26
+\nofMPsegments=\count93
+\nofMParguments=\count94
+\everyMPshowfont=\toks16
+\MPscratchCnt=\count95
+\MPscratchDim=\dimen121
+\MPnumerator=\count96
+\makeMPintoPDFobject=\count97
+\everyMPtoPDFconversion=\toks17
+) (/usr/share/texlive/texmf-dist/tex/generic/oberdiek/pdftexcmds.sty
+Package: pdftexcmds 2016/05/21 v0.22 Utility functions of pdfTeX for LuaTeX (HO
+)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ifluatex.sty
+Package: ifluatex 2016/05/16 v1.4 Provides the ifluatex switch (HO)
+Package ifluatex Info: LuaTeX not detected.
+)
+Package pdftexcmds Info: LuaTeX not detected.
+Package pdftexcmds Info: \pdf@primitive is available.
+Package pdftexcmds Info: \pdf@ifprimitive is available.
+Package pdftexcmds Info: \pdfdraftmode found.
+)
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/epstopdf-base.sty
+Package: epstopdf-base 2016/05/15 v2.6 Base part for package epstopdf
+
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/grfext.sty
+Package: grfext 2016/05/16 v1.2 Manage graphics extensions (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/kvdefinekeys.sty
+Package: kvdefinekeys 2016/05/16 v1.4 Define keys (HO)
+))
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/kvoptions.sty
+Package: kvoptions 2016/05/16 v3.12 Key value format for package options (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/kvsetkeys.sty
+Package: kvsetkeys 2016/05/16 v1.17 Key value parser (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/etexcmds.sty
+Package: etexcmds 2016/05/16 v1.6 Avoid name clashes with e-TeX commands (HO)
+Package etexcmds Info: Could not find \expanded.
+(etexcmds)             That can mean that you are not using pdfTeX 1.50 or
+(etexcmds)             that some package has redefined \expanded.
+(etexcmds)             In the latter case, load this package earlier.
+)))
+Package epstopdf-base Info: Redefining graphics rule for `.eps' on input line 4
+38.
+Package grfext Info: Graphics extension search list:
+(grfext)             [.png,.pdf,.jpg,.mps,.jpeg,.jbig2,.jb2,.PNG,.PDF,.JPG,.JPE
+G,.JBIG2,.JB2,.eps]
+(grfext)             \AppendGraphicsExtensions on input line 456.
+
+(/usr/share/texlive/texmf-dist/tex/latex/latexconfig/epstopdf-sys.cfg
+File: epstopdf-sys.cfg 2010/07/13 v1.3 Configuration of (r)epstopdf for TeX Liv
+e
+))
+Package caption Info: Begin \AtBeginDocument code.
+Package caption Info: End \AtBeginDocument code.
+
+*geometry* detected driver: dvips
+*geometry* verbose mode - [ preamble ] result:
+* driver: dvips
+* paper: custom
+* layout: <same size as paper>
+* layoutoffset:(h,v)=(0.0pt,0.0pt)
+* vratio: 1:1
+* modes: 
+* h-part:(L,W,R)=(54.2025pt, 325.215pt, 54.2025pt)
+* v-part:(T,H,B)=(79.49689pt, 491.43622pt, 79.49689pt)
+* \paperwidth=433.62pt
+* \paperheight=650.43pt
+* \textwidth=325.215pt
+* \textheight=491.43622pt
+* \oddsidemargin=-18.06749pt
+* \evensidemargin=-18.06749pt
+* \topmargin=-29.7731pt
+* \headheight=12.0pt
+* \headsep=25.0pt
+* \topskip=11.0pt
+* \footskip=30.0pt
+* \marginparwidth=59.0pt
+* \marginparsep=10.0pt
+* \columnsep=10.0pt
+* \skip\footins=10.0pt plus 4.0pt minus 2.0pt
+* \hoffset=0.0pt
+* \voffset=0.0pt
+* \mag=1000
+* \@twocolumnfalse
+* \@twosidefalse
+* \@mparswitchfalse
+* \@reversemarginfalse
+* (1in=72.27pt=25.4mm, 1cm=28.453pt)
+
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <12> on input line 12.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <8> on input line 12.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <6> on input line 12.
+
+LaTeX Warning: No \author given.
+
+
+Underfull \hbox (badness 10000) in paragraph at lines 16--18
+
+ []
+
+<../pics/DSCN2180.JPG, id=1, 803.0pt x 602.25pt>
+File: ../pics/DSCN2180.JPG Graphic file (type jpg)
+ <use ../pics/DSCN2180.JPG>
+Package pdftex.def Info: ../pics/DSCN2180.JPG used on input line 19.
+(pdftex.def)             Requested size: 321.1943pt x 240.89572pt.
+
+
+Package caption Warning: \captionsetup{type*=...} or \captionof
+(caption)                outside box or environment on input line 20.
+See the caption package documentation for explanation.
+
+
+Overfull \hbox (12.97931pt too wide) in paragraph at lines 19--20
+[][] 
+ []
+
+[1
+Non-PDF special ignored!
+
+{/var/lib/texmf/fonts/map/pdftex/updmap/pdftex.map} <../pics/DSCN2180.JPG>]
+LaTeX Font Info:    Try loading font information for OMS+cmr on input line 25.
+ (/usr/share/texlive/texmf-dist/tex/latex/base/omscmr.fd
+File: omscmr.fd 2014/09/29 v2.5h Standard LaTeX font definitions
+)
+LaTeX Font Info:    Font shape `OMS/cmr/m/n' in size <10.95> not available
+(Font)              Font shape `OMS/cmsy/m/n' tried instead on input line 25.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <10.95> on input line 34.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <9> on input line 34.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <5> on input line 34.
+
+Underfull \hbox (badness 10000) in paragraph at lines 37--38
+[]\OT1/cmr/m/n/10.95 From https://design.goeszen.com/convert-image-for-oled-
+ []
+
+[2]
+Underfull \hbox (badness 10000) in paragraph at lines 50--51
+[]\OT1/cmr/m/n/10.95 https://thecavepearlproject.org/2019/02/25/no-parts-temper
+ature-
+ []
+
+[3]
+Underfull \hbox (badness 10000) in paragraph at lines 69--71
+
+ []
+
+<../pics/DSCN2610.JPG, id=22, 803.0pt x 602.25pt>
+File: ../pics/DSCN2610.JPG Graphic file (type jpg)
+ <use ../pics/DSCN2610.JPG>
+Package pdftex.def Info: ../pics/DSCN2610.JPG used on input line 73.
+(pdftex.def)             Requested size: 281.05421pt x 210.79065pt.
+
+[4] [5 <../pics/DSCN2610.JPG>]
+<../pics/esr_impedance_capacitance.png, id=29, 697.10437pt x 421.69917pt>
+File: ../pics/esr_impedance_capacitance.png Graphic file (type png)
+
+<use ../pics/esr_impedance_capacitance.png>
+Package pdftex.def Info: ../pics/esr_impedance_capacitance.png used on input li
+ne 84.
+(pdftex.def)             Requested size: 348.55133pt x 210.84906pt.
+
+Overfull \hbox (23.33633pt too wide) in paragraph at lines 84--85
+[][] 
+ []
+
+[6 <../pics/esr_impedance_capacitance.png (PNG copy)>]
+Overfull \hbox (48.4497pt too wide) in paragraph at lines 92--92
+[] \OT1/cmtt/m/n/10.95 https://en.wikipedia.org/w/index.php\title=Aluminum_elec
+trolytic 
+ []
+
+[7] <../pics/LC_Filter.png, id=38, 589.4522pt x 206.27063pt>
+File: ../pics/LC_Filter.png Graphic file (type png)
+
+<use ../pics/LC_Filter.png>
+Package pdftex.def Info: ../pics/LC_Filter.png used on input line 119.
+(pdftex.def)             Requested size: 442.08806pt x 154.70258pt.
+
+Overfull \hbox (116.87306pt too wide) in paragraph at lines 119--120
+ [] 
+ []
+
+[8 <../pics/LC_Filter.png>]
+<../pics/DSCN2845.JPG, id=44, 1003.75pt x 752.8125pt>
+File: ../pics/DSCN2845.JPG Graphic file (type jpg)
+
+<use ../pics/DSCN2845.JPG>
+Package pdftex.def Info: ../pics/DSCN2845.JPG used on input line 129.
+(pdftex.def)             Requested size: 401.49289pt x 301.11966pt.
+
+Overfull \hbox (76.2779pt too wide) in paragraph at lines 129--130
+ [] 
+ []
+
+[9 <../pics/DSCN2845.JPG>]
+Underfull \hbox (badness 10000) in paragraph at lines 148--149
+[]\OT1/cmr/m/n/10.95 Various, \OT1/cmr/m/it/10.95 https://www.eevblog.com/forum
+/projects/dreaded-
+ []
+
+
+Underfull \hbox (badness 10000) in paragraph at lines 148--149
+\OT1/cmr/m/n/10.95 also https://www.eevblog.com/forum/beginners/car-engine-
+ []
+
+
+Underfull \hbox (badness 10000) in paragraph at lines 151--152
+[]\OT1/cmr/m/it/10.95 https://partofthething.com/thoughts/building-a-low-pass-f
+ilter-
+ []
+
+
+Underfull \hbox (badness 10000) in paragraph at lines 151--152
+\OT1/cmr/m/it/10.95 to-remove-alternator-whine-in-my-car/\OT1/cmr/m/n/10.95 . P
+ic-ture guide and
+ []
+
+[10] [11] (./25.aux) ) 
+Here is how much of TeX's memory you used:
+ 3568 strings out of 494945
+ 54399 string characters out of 6181032
+ 119070 words of memory out of 5000000
+ 6834 multiletter control sequences out of 15000+600000
+ 10544 words of font info for 37 fonts, out of 8000000 for 9000
+ 14 hyphenation exceptions out of 8191
+ 39i,8n,39p,867b,274s stack positions out of 5000i,500n,10000p,200000b,80000s
+</usr/share/texlive/texmf-dist/fonts/type1/public/amsfont
+s/cm/cmbx10.pfb></usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/c
+mbx12.pfb></usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmr10.p
+fb></usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmr12.pfb></us
+r/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmr6.pfb></usr/share/
+texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmr8.pfb></usr/share/texlive/
+texmf-dist/fonts/type1/public/amsfonts/cm/cmr9.pfb></usr/share/texlive/texmf-di
+st/fonts/type1/public/amsfonts/cm/cmsy10.pfb></usr/share/texlive/texmf-dist/fon
+ts/type1/public/amsfonts/cm/cmti10.pfb></usr/share/texlive/texmf-dist/fonts/typ
+e1/public/amsfonts/cm/cmtt10.pfb>
+Output written on 25.pdf (11 pages, 791906 bytes).
+PDF statistics:
+ 87 PDF objects out of 1000 (max. 8388607)
+ 57 compressed objects within 1 object stream
+ 0 named destinations out of 1000 (max. 500000)
+ 26 words of extra memory for PDF output out of 10000 (max. 10000000)
+

Car_Stereo_Replacement/docs/25.tex

@@ -0,0 +1,154 @@
+\documentclass[11pt]{article}
+%Gummi|065|=)
+\title{\textbf{Car Stereo Replacement}}
+\usepackage{graphicx,caption}
+%\author{Steak Electronics}
+\date{02/13/20}
+
+\usepackage{xcolor}
+\usepackage[vcentering,dvips]{geometry}
+\geometry{papersize={6in,9in},total={4.5in,6.8in}}
+\begin{document}
+\maketitle
+%\tableofcontents
+
+\section{Car Stereo Replacement}
+Replacing a car stereo. I could just go to ebay, and buy a used car stereo, but where's the fun in that? Let's DIY a car stereo from a PCB used as a frontplate, a connector for my vehicle, and an audio amplifier. I'll connect in signal from an audio player.
+\\
+
+\includegraphics[scale=0.4]{../pics/DSCN2180.JPG}
+\captionof{figure}{PCB rev 1}
+
+\subsection{Items Included}
+I thought I would include the following:
+\begin{itemize}
+\item Arduino Nano
+\item Voltage and Gnd Breakout
+\item I2C Display
+\item Voltage Readout (of BAT)
+\item Current Readout (being drawn)
+\item Amplifier ``Lvpin LP-838''
+\end{itemize}
+I also wanted to have the connectors that eurorack and synth designers use for mono audio cables, but the cables turned out too expensive. The current readout didn't work initially, and I haven't gotten to fixing it yet.
+\subsubsection{I2C OLED display}
+Just for fun, I bought an I2C oled display and am going to use it to display something.\footnote{It's an Arduino Uno, you can put almost anything on this.} Notes on this:
+Using the adafruit SSD1306 and GFX library (this procedure is well covered in other places), you can load an example sketch and get it running. First thing to change is to remove the Adafruit logo and replace it with my own. Let's do that.
+
+From https://design.goeszen.com/convert-image-for-oled-display.html
+\begin{verbatim}
+I'm on Linux here and found that the readily-available 
+ImageMagick package will do the trick for you without
+ any scripting. And runs on the CLI! Simple as that:
+
+    convert some_image.png some.image.mono
+\end{verbatim}
+That's efficient. But it didn't really work out. Too much work, I don't need it that bad. Have to convert it to something the c compiler can read. I instead, just deleted their logo. Good enough for now.
+\subsubsection{Internal AVR Temperature Sensor}
+
+I setup the code to read from the internal temp sensor on the duino. However there is also this:
+
+https://thecavepearlproject.org/2019/02/25/no-parts-temperature-measurement-with-arduino-pro-mini-to-0-005c-or-better/
+
+This would be something to do for more resolution. The built in sensor is not very good, so this above link would be great. Hack a day also covers it. 
+
+\subsection{Wiring Pinout is wrong on Internet - Cable has labels}
+I looked at the picture I have detailing the pinout of my car connector (Delco Delphi radio wiring diagram.jpg in resources). It's close, but not 100\% correct. I found that the cable itself has small text labels on each wire which explain which everything does. I didn't notice earlier, as I didn't look close enough (and no one mentioned this).
+
+\subsection{Arduino VReg Blowout}
+I had a knock off Arduino Nano, and the vreg blew out. I have some other vregs to replace it. I didn't have this problem with an Uno that I use as a ceiling dome light. Although that one is not left on as long, usually. 
+
+\subsection{Amplifier}
+The amplifier I used is one of the cheapest avialable on ebay. I'm not proud. I'm poor. I had to take it apart, and reseat the amplifier ICs as the tab was not making contact with the chassis for one of them. I also added thermal paste. This amp is underpowered for my car, and may need replacing. It gets a bit hot.\footnote{This was later solved via using series low impedance caps on the output (coupling amp to speakers).}
+
+Some other issues with this amplifier are that the output connectors can get pushed back, there is only one output connector option, and it must run on battery power, as a 12V 1A or 2A will not power it. Finally, there is a 6V DC bias on output. No output audio isolation, which means you get car noise.
+
+\subsection{AC Audio Coupling to Remove DC Noise from Auto}
+I had some fun with this one. Many videos on this in the video folder. I started with the speakers being directly fed by the amplifier. This worked, but there was some noise coming through. Cars are noisy, this is not surprising. I would've preferred the amplifier to isolate the outputs, but no luck... At this point, I considered two options to block DC and allow AC. 1) Use a transformer. 2) Use capacitors.\footnote{A third option would've been to use a second set of batteries, but that would be laborious.}
+
+\subsubsection{Ground Isolator}
+I had been given a Ground isolator, which was two small transformers on a pcb intended to pass audio from a car powered signal source into the car speakers. I tried this isolator on the output of the speakers, and while it worked, the volume was lower, and it was impractical. I knew as soon as I heard the volume, that the issue was an impedance matching problem. The transformers were too small. They were intended for signal sources, not amplifier outputs. Onto option \#2.
+\\
+
+\begin{center}
+\includegraphics[scale=0.35]{../pics/DSCN2610.JPG}
+\captionof{figure}{Ground Loop Isolator.}
+\end{center}
+\subsubsection{Capacitor Audio Coupling}
+My initial thoughts here were: ``Let's be careful and use non polarized caps''. I bought some 0.22uf and 0.022uf polyester film capacitors at Electronics Plus, the local radioshack replacement, and tried them. No sound. After adjusting the connectors on the amp (which were admittedly loose - it's easy to push them back on the amplifier if you are not careful) I found that the capacitors didn't work. One problem was evident in the oscope. I only used one capacitor on the + output of the speaker amp, but the Amp biases the signal 6 volts. So I needed two. After that was resolved, the signal came through on the output of the capacitor, as viewed on the scope, however there was no sound output. I tried the safe way. It's time to break some rules. 
+
+I grabbed some 1uf (electrolytic polarized) caps I had, and tried these. Again, no sound. Not giving up, I grabbed some 1000uf 'lytics, and tried once more. Now it worked.
+
+\subsubsection{Impedance / ESR of capacitors failing to pass enough power of signal}
+Capacitors are rated for impedance. Some data sheets also call this ESR, it appears after a quick look. It's either in there as impedance or ESR. It's not initially an issue if you are using the capacitor as a DC reservoir, but if you use it in an AC coupling situation then things get interesting. A high impedance, or ESR will block what a low one won't. In this example, it's as simple as the Amplfier either being able to power a speaker or not. Higher capacity caps will have lower impedance. See the picture. Other brands put impedance in a graph, or just call it impedance. 
+
+\includegraphics[scale=0.5]{../pics/esr_impedance_capacitance.png}
+\captionof{figure}{Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.}
+
+\subsubsection{Wikipedia on Impedance}
+
+\emph{In general, a capacitor is seen as a storage component for electric energy. But this is only one capacitor function. A capacitor can also act as an AC resistor. Especially aluminum electrolytic capacitors are used in many applications as a decoupling capacitors to filter or bypass undesired biased AC frequencies to the ground or for capacitive coupling of audio AC signals. Then the dielectric is used only for blocking DC. For such applications the AC resistance, the impedance is as important as the capacitance value. }
+\begin{verbatim} https://en.wikipedia.org/w/index.php\title=Aluminum_electrolytic
+_capacitor&oldid=940281525
+\end{verbatim}
+Essentially, what I learned today.
+
+\subsection{DIY Amp}
+I was flipping through Practical Electronics for Inventors\cite{Scherz}(page 959), when I came across an audio amplifier. He also gives one at the chapter on Semiconductors (pg. 467), although the former is more detailed. With a reasonably simple schematic available, and a high likelihood of it working, I say why not: let's build it up.
+
+I've noticed that the ``Lvpin LP-838'' amplifier I'm using is underpowered for my two front speakers \footnote{Although it seems it would work for one channel, so two of them might be enough. It's rated for 20W, so that is about 15-20W per channel req'd. It works at 20W for both, just that it heats up too much. Multiple ebay sellers have it misquoted at 200W. Just an extra 0, no biggie. Based on all this, it appears each channel of my car speaker needs about 15 watts to be on the safe side. The example schematic is 16 watts. Two should suffice.}, so I will make two of the provided 16 watt amps.
+
+\subsubsection{LM383 is Obsolete}
+That explains why I haven't heard of it. The chip is obsolete. Some sell it on ebay for about \$5 each.
+
+As a different route, could I use some other power amplifier op amp, with the same pinout? Hm... Aha, the LM1875 has the same pinout. Let's use that.\footnote{How did I find this? I searched Digikey for the LM383 sold by rochester, noted it was it the category of Linear - Amplifiers - Audio, chose that, then searched for everything in the same package (TO220-5). Came right up. If this hadn't worked, I would've wanted to try other sites: Farnells, Mouser, etc...}
+
+Will it work with the same schematic? Questionable. May still need to buy a LM383, along with the LM1875, as backup. I might also try a generic power op amp.
+
+Amplfiers are the expensive bom item here.
+
+\subsection{Noise remains with Speaker Isolation}
+I've isolated the speakers from DC with the caps, but noise remains. My next idea was a DC-DC isolated supply. But, I found two threads on eevblog forums\cite{eevblog}, and they recommend a power line filter (they also mention the isolated supply). A filter with a coil and cap (2200uf even low enough) I can quickly build up.
+
+I also want to fix up my portable CRO, I obtained the other day. That needs batteries.
+
+One thing I noticed, is that the amplifier seems to no longer heat up, since the caps were added. Perhaps the DC bias was the cause. I need to confirm this.
+
+I was able to pull an 16.5V transformer from industrial equipment, so let's try this filter:
+
+\begin{center}
+\includegraphics[scale=0.75]{../pics/LC_Filter.png}
+\captionof{figure}{This picture was more difficult to download than it should've been. Spent 3 minutes on this. At least its not a discourse javascript pile of trash.} 
+\end{center}
+
+\subsection{Low Pass Filter to remove Alternator Hum}
+I have built the Low Pass Filter consisting of a 120 to 16V AC transformer and a 2200uf Cap (LC filter). I tested it on my signal gen, and it works quite well. No AC ripple comes through. I tested it in the car, and success - there is no more alternator hum. However...
+
+There is still some noise on the speakers. It is not audible. I can't hear it, but I can feel my ears get sensitive after listening for a song or two. There must be something else getting through that is causing my ears to become sensitive. Either that, or I was not in the mood to listen to my stereo. See the picture of the filter below.
+
+\begin{center}
+\includegraphics[scale=0.4]{../pics/DSCN2845.JPG}
+\captionof{figure}{Fused supply from 12V car battery goes into the female barrel jack, into and out the secondary of the transformer leads. The primary is left floating. There is 2000uf 20\% 25V electrolytics after the inductor. Eliminates all alternator hum. Remember that as men, we are in the business of making tools. I have made it a goal to create perf board prototypes, and usable electronic devices, such as this LC filter. This is modular (via barrel plugs) and sturdy enough that I can use it to filter any power supply.}
+\end{center}
+
+\subsection{The story so far}
+So far I have found the following:
+\begin{itemize}
+\item By using electrolytic caps in series to block DC Bias output on the amplifier audio, I reduced unnecessary power dissipation on the amp (doesn't heat up anymore)
+  \item By putting an LC (AC) filter on the 12V input, I was able to block alternator noise.
+\end{itemize}
+I have yet to consider this project done. I suspect some noise still on the audio output. It must be coupled from the power supply.
+
+\subsection{References}
+\begin{thebibliography}{99}
+\bibitem{Scherz}
+  Paul Scherz, and Simon Monk,
+  \emph{Practical Electronics for Inventors}, fourth edition - 2016, McGraw Hill.
+
+\bibitem{eevblog}
+  Various, \emph{https://www.eevblog.com/forum/projects/dreaded-alternator-whine-in-car-stereo/25/} Retrieved 2020-02-21. see also https://www.eevblog.com/forum/beginners/car-engine-signal-interference-with-cell-phone/
+
+\bibitem{partofthe}
+  \emph{https://partofthething.com/thoughts/building-a-low-pass-filter-to-remove-alternator-whine-in-my-car/}. Picture guide and showing basic build in project box. Eevblog users mention you may be able to use the secondary of a transformer, to avoid building the coil.
+  \end{thebibliography}
+
+\end{document}

Car_Stereo_Replacement/docs/25.tex~

@@ -0,0 +1,151 @@
+\documentclass[11pt]{article}
+%Gummi|065|=)
+\title{\textbf{Car Stereo Replacement}}
+\usepackage{graphicx,caption}
+%\author{Steak Electronics}
+\date{02/13/20}
+\begin{document}
+
+\maketitle
+%\tableofcontents
+
+\section{Car Stereo Replacement}
+Replacing a car stereo. I could just go to ebay, and buy a used car stereo, but where's the fun in that? Let's DIY a car stereo from a PCB used as a frontplate, a connector for my vehicle, and an audio amplifier. I'll connect in signal from an audio player.
+\\
+
+\includegraphics[scale=0.4]{../pics/DSCN2180.JPG}
+\captionof{figure}{PCB rev 1}
+
+\subsection{Items Included}
+I thought I would include the following:
+\begin{itemize}
+\item Arduino Nano
+\item Voltage and Gnd Breakout
+\item I2C Display
+\item Voltage Readout (of BAT)
+\item Current Readout (being drawn)
+\item Amplifier ``Lvpin LP-838''
+\end{itemize}
+I also wanted to have the connectors that eurorack and synth designers use for mono audio cables, but the cables turned out too expensive. The current readout didn't work initially, and I haven't gotten to fixing it yet.
+\subsubsection{I2C OLED display}
+Just for fun, I bought an I2C oled display and am going to use it to display something.\footnote{It's an Arduino Uno, you can put almost anything on this.} Notes on this:
+Using the adafruit SSD1306 and GFX library (this procedure is well covered in other places), you can load an example sketch and get it running. First thing to change is to remove the Adafruit logo and replace it with my own. Let's do that.
+
+From https://design.goeszen.com/convert-image-for-oled-display.html
+\begin{verbatim}
+I'm on Linux here and found that the readily-available 
+ImageMagick package will do the trick for you without
+ any scripting. And runs on the CLI! Simple as that:
+
+    convert some_image.png some.image.mono
+\end{verbatim}
+That's efficient. But it didn't really work out. Too much work, I don't need it that bad. Have to convert it to something the c compiler can read. I instead, just deleted their logo. Good enough for now.
+\subsubsection{Internal AVR Temperature Sensor}
+
+I setup the code to read from the internal temp sensor on the duino. However there is also this:
+
+https://thecavepearlproject.org/2019/02/25/no-parts-temperature-measurement-with-arduino-pro-mini-to-0-005c-or-better/
+
+This would be something to do for more resolution. The built in sensor is not very good, so this above link would be great. Hack a day also covers it. 
+
+\subsection{Wiring Pinout is wrong on Internet - Cable has labels}
+I looked at the picture I have detailing the pinout of my car connector (Delco Delphi radio wiring diagram.jpg in resources). It's close, but not 100\% correct. I found that the cable itself has small text labels on each wire which explain which everything does. I didn't notice earlier, as I didn't look close enough (and no one mentioned this).
+
+\subsection{Arduino VReg Blowout}
+I had a knock off Arduino Nano, and the vreg blew out. I have some other vregs to replace it. I didn't have this problem with an Uno that I use as a ceiling dome light. Although that one is not left on as long, usually. 
+
+\subsection{Amplifier}
+The amplifier I used is one of the cheapest avialable on ebay. I'm not proud. I'm poor. I had to take it apart, and reseat the amplifier ICs as the tab was not making contact with the chassis for one of them. I also added thermal paste. This amp is underpowered for my car, and may need replacing. It gets a bit hot.\footnote{This was later solved via using series low impedance caps on the output (coupling amp to speakers).}
+
+Some other issues with this amplifier are that the output connectors can get pushed back, there is only one output connector option, and it must run on battery power, as a 12V 1A or 2A will not power it. Finally, there is a 6V DC bias on output. No output audio isolation, which means you get car noise.
+
+\subsection{AC Audio Coupling to Remove DC Noise from Auto}
+I had some fun with this one. Many videos on this in the video folder. I started with the speakers being directly fed by the amplifier. This worked, but there was some noise coming through. Cars are noisy, this is not surprising. I would've preferred the amplifier to isolate the outputs, but no luck... At this point, I considered two options to block DC and allow AC. 1) Use a transformer. 2) Use capacitors.\footnote{A third option would've been to use a second set of batteries, but that would be laborious.}
+
+\subsubsection{Ground Isolator}
+I had been given a Ground isolator, which was two small transformers on a pcb intended to pass audio from a car powered signal source into the car speakers. I tried this isolator on the output of the speakers, and while it worked, the volume was lower, and it was impractical. I knew as soon as I heard the volume, that the issue was an impedance matching problem. The transformers were too small. They were intended for signal sources, not amplifier outputs. Onto option \#2.
+\\
+
+\begin{center}
+\includegraphics[scale=0.35]{../pics/DSCN2610.JPG}
+\captionof{figure}{Ground Loop Isolator.}
+\end{center}
+\subsubsection{Capacitor Audio Coupling}
+My initial thoughts here were: ``Let's be careful and use non polarized caps''. I bought some 0.22uf and 0.022uf polyester film capacitors at Electronics Plus, the local radioshack replacement, and tried them. No sound. After adjusting the connectors on the amp (which were admittedly loose - it's easy to push them back on the amplifier if you are not careful) I found that the capacitors didn't work. One problem was evident in the oscope. I only used one capacitor on the + output of the speaker amp, but the Amp biases the signal 6 volts. So I needed two. After that was resolved, the signal came through on the output of the capacitor, as viewed on the scope, however there was no sound output. I tried the safe way. It's time to break some rules. 
+
+I grabbed some 1uf (electrolytic polarized) caps I had, and tried these. Again, no sound. Not giving up, I grabbed some 1000uf 'lytics, and tried once more. Now it worked.
+
+\subsubsection{Impedance / ESR of capacitors failing to pass enough power of signal}
+Capacitors are rated for impedance. Some data sheets also call this ESR, it appears after a quick look. It's either in there as impedance or ESR. It's not initially an issue if you are using the capacitor as a DC reservoir, but if you use it in an AC coupling situation then things get interesting. A high impedance, or ESR will block what a low one won't. In this example, it's as simple as the Amplfier either being able to power a speaker or not. Higher capacity caps will have lower impedance. See the picture. Other brands put impedance in a graph, or just call it impedance. 
+
+\includegraphics[scale=0.5]{../pics/esr_impedance_capacitance.png}
+\captionof{figure}{Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.}
+
+\subsubsection{Wikipedia on Impedance}
+
+\emph{In general, a capacitor is seen as a storage component for electric energy. But this is only one capacitor function. A capacitor can also act as an AC resistor. Especially aluminum electrolytic capacitors are used in many applications as a decoupling capacitors to filter or bypass undesired biased AC frequencies to the ground or for capacitive coupling of audio AC signals. Then the dielectric is used only for blocking DC. For such applications the AC resistance, the impedance is as important as the capacitance value. }
+\begin{verbatim} https://en.wikipedia.org/w/index.php\title=Aluminum_electrolytic
+_capacitor&oldid=940281525
+\end{verbatim}
+Essentially, what I learned today.
+
+\subsection{DIY Amp}
+I was flipping through Practical Electronics for Inventors\cite{Scherz}(page 959), when I came across an audio amplifier. He also gives one at the chapter on Semiconductors (pg. 467), although the former is more detailed. With a reasonably simple schematic available, and a high likelihood of it working, I say why not: let's build it up.
+
+I've noticed that the ``Lvpin LP-838'' amplifier I'm using is underpowered for my two front speakers \footnote{Although it seems it would work for one channel, so two of them might be enough. It's rated for 20W, so that is about 15-20W per channel req'd. It works at 20W for both, just that it heats up too much. Multiple ebay sellers have it misquoted at 200W. Just an extra 0, no biggie. Based on all this, it appears each channel of my car speaker needs about 15 watts to be on the safe side. The example schematic is 16 watts. Two should suffice.}, so I will make two of the provided 16 watt amps.
+
+\subsubsection{LM383 is Obsolete}
+That explains why I haven't heard of it. The chip is obsolete. Some sell it on ebay for about \$5 each.
+
+As a different route, could I use some other power amplifier op amp, with the same pinout? Hm... Aha, the LM1875 has the same pinout. Let's use that.\footnote{How did I find this? I searched Digikey for the LM383 sold by rochester, noted it was it the category of Linear - Amplifiers - Audio, chose that, then searched for everything in the same package (TO220-5). Came right up. If this hadn't worked, I would've wanted to try other sites: Farnells, Mouser, etc...}
+
+Will it work with the same schematic? Questionable. May still need to buy a LM383, along with the LM1875, as backup. I might also try a generic power op amp.
+
+Amplfiers are the expensive bom item here.
+
+\subsection{Noise remains with Speaker Isolation}
+I've isolated the speakers from DC with the caps, but noise remains. My next idea was a DC-DC isolated supply. But, I found two threads on eevblog forums\cite{eevblog}, and they recommend a power line filter (they also mention the isolated supply). A filter with a coil and cap (2200uf even low enough) I can quickly build up.
+
+I also want to fix up my portable CRO, I obtained the other day. That needs batteries.
+
+One thing I noticed, is that the amplifier seems to no longer heat up, since the caps were added. Perhaps the DC bias was the cause. I need to confirm this.
+
+I was able to pull an 16.5V transformer from industrial equipment, so let's try this filter:
+
+\begin{center}
+\includegraphics[scale=0.75]{../pics/LC_Filter.png}
+\captionof{figure}{This picture was more difficult to download than it should've been. Spent 3 minutes on this. At least its not a discourse javascript pile of trash.} 
+\end{center}
+
+\subsection{Low Pass Filter to remove Alternator Hum}
+I have built the Low Pass Filter consisting of a 120 to 16V AC transformer and a 2200uf Cap (LC filter). I tested it on my signal gen, and it works quite well. No AC ripple comes through. I tested it in the car, and success - there is no more alternator hum. However...
+
+There is still some noise on the speakers. It is not audible. I can't hear it, but I can feel my ears get sensitive after listening for a song or two. There must be something else getting through that is causing my ears to become sensitive. Either that, or I was not in the mood to listen to my stereo. See the picture of the filter below.
+
+\begin{center}
+\includegraphics[scale=0.4]{../pics/DSCN2845.JPG}
+\captionof{figure}{Fused supply from 12V car battery goes into the female barrel jack, into and out the secondary of the transformer leads. The primary is left floating. There is 2000uf 20\% 25V electrolytics after the inductor. Eliminates all alternator hum. Remember that as men, we are in the business of making tools. I have made it a goal to create perf board prototypes, and usable electronic devices, such as this LC filter. This is modular (via barrel plugs) and sturdy enough that I can use it to filter any power supply.}
+\end{center}
+
+\subsection{The story so far}
+So far I have found the following:
+\begin{itemize}
+\item By using electrolytic caps in series to block DC Bias output on the amplifier audio, I reduced unnecessary power dissipation on the amp (doesn't heat up anymore)
+  \item By putting an LC (AC) filter on the 12V input, I was able to block alternator noise.
+\end{itemize}
+I have yet to consider this project done. I suspect some noise still on the audio output. It must be coupled from the power supply.
+
+\subsection{References}
+\begin{thebibliography}{99}
+\bibitem{Scherz}
+  Paul Scherz, and Simon Monk,
+  \emph{Practical Electronics for Inventors}, fourth edition - 2016, McGraw Hill.
+
+\bibitem{eevblog}
+  Various, \emph{https://www.eevblog.com/forum/projects/dreaded-alternator-whine-in-car-stereo/25/} Retrieved 2020-02-21. see also https://www.eevblog.com/forum/beginners/car-engine-signal-interference-with-cell-phone/
+
+\bibitem{partofthe}
+  \emph{https://partofthething.com/thoughts/building-a-low-pass-filter-to-remove-alternator-whine-in-my-car/}. Picture guide and showing basic build in project box. Eevblog users mention you may be able to use the secondary of a transformer, to avoid building the coil.
+  \end{thebibliography}
+
+\end{document}

Car_Stereo_Replacement/docs/26.aux

@@ -0,0 +1,29 @@
+\relax 
+\@writefile{toc}{\contentsline {section}{\numberline {1}Car Stereo Replacement}{1}}
+\@writefile{lof}{\contentsline {figure}{\numberline {1}{\ignorespaces PCB rev 1\relax }}{1}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.1}Items Included}{2}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.1.1}I2C OLED display}{2}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.1.2}Internal AVR Temperature Sensor}{3}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.2}Wiring Pinout is wrong on Internet - Cable has labels}{3}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.3}Arduino VReg Blowout}{3}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.4}Amplifier}{3}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.5}AC Audio Coupling to Remove DC Noise from Auto}{4}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.5.1}Ground Isolator}{4}}
+\@writefile{lof}{\contentsline {figure}{\numberline {2}{\ignorespaces Ground Loop Isolator.\relax }}{5}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.5.2}Capacitor Audio Coupling}{5}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.5.3}Impedance / ESR of capacitors failing to pass enough power of signal}{6}}
+\@writefile{lof}{\contentsline {figure}{\numberline {3}{\ignorespaces Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.\relax }}{6}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.5.4}Wikipedia on Impedance}{6}}
+\citation{Scherz}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.6}DIY Amp}{7}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {1.6.1}LM383 is Obsolete}{7}}
+\citation{eevblog}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.7}Noise remains with Speaker Isolation}{8}}
+\@writefile{lof}{\contentsline {figure}{\numberline {4}{\ignorespaces This picture was more difficult to download than it should've been. Spent 3 minutes on this. At least its not a discourse javascript pile of trash.\relax }}{8}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.8}Low Pass Filter to remove Alternator Hum}{9}}
+\@writefile{lof}{\contentsline {figure}{\numberline {5}{\ignorespaces Fused supply from 12V car battery goes into the female barrel jack, into and out the secondary of the transformer leads. The primary is left floating. There are 2 1000uf 20\% 25V electrolytics after the inductor. Eliminates all alternator hum. Remember that as men, we are in the business of making tools. I have made it a goal to create perf board prototypes, and usable electronic devices, such as this LC filter. This is modular (via barrel plugs) and sturdy enough that I can use it to filter any power supply.\relax }}{9}}
+\bibcite{Scherz}{1}
+\bibcite{eevblog}{2}
+\bibcite{partofthe}{3}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.9}The story so far}{10}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {1.10}References}{10}}

Car_Stereo_Replacement/docs/26.log

@@ -0,0 +1,389 @@
+This is pdfTeX, Version 3.14159265-2.6-1.40.17 (TeX Live 2016/Debian) (preloaded format=pdflatex 2019.8.17)  20 MAR 2020 22:37
+entering extended mode
+ restricted \write18 enabled.
+ %&-line parsing enabled.
+**/home/layoutdev/Desktop/code/documentation_general/Electronics_Projects_2019/
+Car_Stereo_Replacement/docs/26.tex
+
+(/home/layoutdev/Desktop/code/documentation_general/Electronics_Projects_2019/C
+ar_Stereo_Replacement/docs/26.tex
+LaTeX2e <2017/01/01> patch level 3
+Babel <3.9r> and hyphenation patterns for 3 language(s) loaded.
+(/usr/share/texlive/texmf-dist/tex/latex/base/article.cls
+Document Class: article 2014/09/29 v1.4h Standard LaTeX document class
+(/usr/share/texlive/texmf-dist/tex/latex/base/size11.clo
+File: size11.clo 2014/09/29 v1.4h Standard LaTeX file (size option)
+)
+\c@part=\count79
+\c@section=\count80
+\c@subsection=\count81
+\c@subsubsection=\count82
+\c@paragraph=\count83
+\c@subparagraph=\count84
+\c@figure=\count85
+\c@table=\count86
+\abovecaptionskip=\skip41
+\belowcaptionskip=\skip42
+\bibindent=\dimen102
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/graphicx.sty
+Package: graphicx 2014/10/28 v1.0g Enhanced LaTeX Graphics (DPC,SPQR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/keyval.sty
+Package: keyval 2014/10/28 v1.15 key=value parser (DPC)
+\KV@toks@=\toks14
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/graphics.sty
+Package: graphics 2016/10/09 v1.0u Standard LaTeX Graphics (DPC,SPQR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics/trig.sty
+Package: trig 2016/01/03 v1.10 sin cos tan (DPC)
+)
+(/usr/share/texlive/texmf-dist/tex/latex/graphics-cfg/graphics.cfg
+File: graphics.cfg 2016/06/04 v1.11 sample graphics configuration
+)
+Package graphics Info: Driver file: pdftex.def on input line 99.
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics-def/pdftex.def
+File: pdftex.def 2017/01/12 v0.06k Graphics/color for pdfTeX
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/infwarerr.sty
+Package: infwarerr 2016/05/16 v1.4 Providing info/warning/error messages (HO)
+)
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ltxcmds.sty
+Package: ltxcmds 2016/05/16 v1.23 LaTeX kernel commands for general use (HO)
+)
+\Gread@gobject=\count87
+))
+\Gin@req@height=\dimen103
+\Gin@req@width=\dimen104
+)
+(/usr/share/texlive/texmf-dist/tex/latex/caption/caption.sty
+Package: caption 2016/02/21 v3.3-144 Customizing captions (AR)
+
+(/usr/share/texlive/texmf-dist/tex/latex/caption/caption3.sty
+Package: caption3 2016/05/22 v1.7-166 caption3 kernel (AR)
+Package caption3 Info: TeX engine: e-TeX on input line 67.
+\captionmargin=\dimen105
+\captionmargin@=\dimen106
+\captionwidth=\dimen107
+\caption@tempdima=\dimen108
+\caption@indent=\dimen109
+\caption@parindent=\dimen110
+\caption@hangindent=\dimen111
+)
+\c@ContinuedFloat=\count88
+)
+(/usr/share/texlive/texmf-dist/tex/latex/xcolor/xcolor.sty
+Package: xcolor 2016/05/11 v2.12 LaTeX color extensions (UK)
+
+(/usr/share/texlive/texmf-dist/tex/latex/graphics-cfg/color.cfg
+File: color.cfg 2016/01/02 v1.6 sample color configuration
+)
+Package xcolor Info: Driver file: pdftex.def on input line 225.
+Package xcolor Info: Model `cmy' substituted by `cmy0' on input line 1348.
+Package xcolor Info: Model `hsb' substituted by `rgb' on input line 1352.
+Package xcolor Info: Model `RGB' extended on input line 1364.
+Package xcolor Info: Model `HTML' substituted by `rgb' on input line 1366.
+Package xcolor Info: Model `Hsb' substituted by `hsb' on input line 1367.
+Package xcolor Info: Model `tHsb' substituted by `hsb' on input line 1368.
+Package xcolor Info: Model `HSB' substituted by `hsb' on input line 1369.
+Package xcolor Info: Model `Gray' substituted by `gray' on input line 1370.
+Package xcolor Info: Model `wave' substituted by `hsb' on input line 1371.
+)
+(/usr/share/texlive/texmf-dist/tex/latex/geometry/geometry.sty
+Package: geometry 2010/09/12 v5.6 Page Geometry
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ifpdf.sty
+Package: ifpdf 2016/05/14 v3.1 Provides the ifpdf switch
+)
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ifvtex.sty
+Package: ifvtex 2016/05/16 v1.6 Detect VTeX and its facilities (HO)
+Package ifvtex Info: VTeX not detected.
+)
+(/usr/share/texlive/texmf-dist/tex/generic/ifxetex/ifxetex.sty
+Package: ifxetex 2010/09/12 v0.6 Provides ifxetex conditional
+)
+\Gm@cnth=\count89
+\Gm@cntv=\count90
+\c@Gm@tempcnt=\count91
+\Gm@bindingoffset=\dimen112
+\Gm@wd@mp=\dimen113
+\Gm@odd@mp=\dimen114
+\Gm@even@mp=\dimen115
+\Gm@layoutwidth=\dimen116
+\Gm@layoutheight=\dimen117
+\Gm@layouthoffset=\dimen118
+\Gm@layoutvoffset=\dimen119
+\Gm@dimlist=\toks15
+) (./26.aux)
+\openout1 = `26.aux'.
+
+LaTeX Font Info:    Checking defaults for OML/cmm/m/it on input line 11.
+LaTeX Font Info:    ... okay on input line 11.
+LaTeX Font Info:    Checking defaults for T1/cmr/m/n on input line 11.
+LaTeX Font Info:    ... okay on input line 11.
+LaTeX Font Info:    Checking defaults for OT1/cmr/m/n on input line 11.
+LaTeX Font Info:    ... okay on input line 11.
+LaTeX Font Info:    Checking defaults for OMS/cmsy/m/n on input line 11.
+LaTeX Font Info:    ... okay on input line 11.
+LaTeX Font Info:    Checking defaults for OMX/cmex/m/n on input line 11.
+LaTeX Font Info:    ... okay on input line 11.
+LaTeX Font Info:    Checking defaults for U/cmr/m/n on input line 11.
+LaTeX Font Info:    ... okay on input line 11.
+
+(/usr/share/texlive/texmf-dist/tex/context/base/mkii/supp-pdf.mkii
+[Loading MPS to PDF converter (version 2006.09.02).]
+\scratchcounter=\count92
+\scratchdimen=\dimen120
+\scratchbox=\box26
+\nofMPsegments=\count93
+\nofMParguments=\count94
+\everyMPshowfont=\toks16
+\MPscratchCnt=\count95
+\MPscratchDim=\dimen121
+\MPnumerator=\count96
+\makeMPintoPDFobject=\count97
+\everyMPtoPDFconversion=\toks17
+) (/usr/share/texlive/texmf-dist/tex/generic/oberdiek/pdftexcmds.sty
+Package: pdftexcmds 2016/05/21 v0.22 Utility functions of pdfTeX for LuaTeX (HO
+)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ifluatex.sty
+Package: ifluatex 2016/05/16 v1.4 Provides the ifluatex switch (HO)
+Package ifluatex Info: LuaTeX not detected.
+)
+Package pdftexcmds Info: LuaTeX not detected.
+Package pdftexcmds Info: \pdf@primitive is available.
+Package pdftexcmds Info: \pdf@ifprimitive is available.
+Package pdftexcmds Info: \pdfdraftmode found.
+)
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/epstopdf-base.sty
+Package: epstopdf-base 2016/05/15 v2.6 Base part for package epstopdf
+
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/grfext.sty
+Package: grfext 2016/05/16 v1.2 Manage graphics extensions (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/kvdefinekeys.sty
+Package: kvdefinekeys 2016/05/16 v1.4 Define keys (HO)
+))
+(/usr/share/texlive/texmf-dist/tex/latex/oberdiek/kvoptions.sty
+Package: kvoptions 2016/05/16 v3.12 Key value format for package options (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/kvsetkeys.sty
+Package: kvsetkeys 2016/05/16 v1.17 Key value parser (HO)
+
+(/usr/share/texlive/texmf-dist/tex/generic/oberdiek/etexcmds.sty
+Package: etexcmds 2016/05/16 v1.6 Avoid name clashes with e-TeX commands (HO)
+Package etexcmds Info: Could not find \expanded.
+(etexcmds)             That can mean that you are not using pdfTeX 1.50 or
+(etexcmds)             that some package has redefined \expanded.
+(etexcmds)             In the latter case, load this package earlier.
+)))
+Package epstopdf-base Info: Redefining graphics rule for `.eps' on input line 4
+38.
+Package grfext Info: Graphics extension search list:
+(grfext)             [.png,.pdf,.jpg,.mps,.jpeg,.jbig2,.jb2,.PNG,.PDF,.JPG,.JPE
+G,.JBIG2,.JB2,.eps]
+(grfext)             \AppendGraphicsExtensions on input line 456.
+
+(/usr/share/texlive/texmf-dist/tex/latex/latexconfig/epstopdf-sys.cfg
+File: epstopdf-sys.cfg 2010/07/13 v1.3 Configuration of (r)epstopdf for TeX Liv
+e
+))
+Package caption Info: Begin \AtBeginDocument code.
+Package caption Info: End \AtBeginDocument code.
+
+*geometry* detected driver: dvips
+*geometry* verbose mode - [ preamble ] result:
+* driver: dvips
+* paper: custom
+* layout: <same size as paper>
+* layoutoffset:(h,v)=(0.0pt,0.0pt)
+* vratio: 1:1
+* modes: 
+* h-part:(L,W,R)=(54.2025pt, 325.215pt, 54.2025pt)
+* v-part:(T,H,B)=(79.49689pt, 491.43622pt, 79.49689pt)
+* \paperwidth=433.62pt
+* \paperheight=650.43pt
+* \textwidth=325.215pt
+* \textheight=491.43622pt
+* \oddsidemargin=-18.06749pt
+* \evensidemargin=-18.06749pt
+* \topmargin=-29.7731pt
+* \headheight=12.0pt
+* \headsep=25.0pt
+* \topskip=11.0pt
+* \footskip=30.0pt
+* \marginparwidth=59.0pt
+* \marginparsep=10.0pt
+* \columnsep=10.0pt
+* \skip\footins=10.0pt plus 4.0pt minus 2.0pt
+* \hoffset=0.0pt
+* \voffset=0.0pt
+* \mag=1000
+* \@twocolumnfalse
+* \@twosidefalse
+* \@mparswitchfalse
+* \@reversemarginfalse
+* (1in=72.27pt=25.4mm, 1cm=28.453pt)
+
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <12> on input line 12.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <8> on input line 12.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <6> on input line 12.
+
+LaTeX Warning: No \author given.
+
+
+Underfull \hbox (badness 10000) in paragraph at lines 16--18
+
+ []
+
+<../pics/DSCN2180.JPG, id=1, 803.0pt x 602.25pt>
+File: ../pics/DSCN2180.JPG Graphic file (type jpg)
+ <use ../pics/DSCN2180.JPG>
+Package pdftex.def Info: ../pics/DSCN2180.JPG used on input line 19.
+(pdftex.def)             Requested size: 321.1943pt x 240.89572pt.
+
+
+Package caption Warning: \captionsetup{type*=...} or \captionof
+(caption)                outside box or environment on input line 20.
+See the caption package documentation for explanation.
+
+
+Overfull \hbox (12.97931pt too wide) in paragraph at lines 19--20
+[][] 
+ []
+
+[1
+Non-PDF special ignored!
+
+{/var/lib/texmf/fonts/map/pdftex/updmap/pdftex.map} <../pics/DSCN2180.JPG>]
+LaTeX Font Info:    Try loading font information for OMS+cmr on input line 25.
+ (/usr/share/texlive/texmf-dist/tex/latex/base/omscmr.fd
+File: omscmr.fd 2014/09/29 v2.5h Standard LaTeX font definitions
+)
+LaTeX Font Info:    Font shape `OMS/cmr/m/n' in size <10.95> not available
+(Font)              Font shape `OMS/cmsy/m/n' tried instead on input line 25.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <10.95> on input line 34.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <9> on input line 34.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <5> on input line 34.
+
+Underfull \hbox (badness 10000) in paragraph at lines 37--38
+[]\OT1/cmr/m/n/10.95 From https://design.goeszen.com/convert-image-for-oled-
+ []
+
+[2]
+Underfull \hbox (badness 10000) in paragraph at lines 50--51
+[]\OT1/cmr/m/n/10.95 https://thecavepearlproject.org/2019/02/25/no-parts-temper
+ature-
+ []
+
+[3]
+Underfull \hbox (badness 10000) in paragraph at lines 69--71
+
+ []
+
+<../pics/DSCN2610.JPG, id=22, 803.0pt x 602.25pt>
+File: ../pics/DSCN2610.JPG Graphic file (type jpg)
+ <use ../pics/DSCN2610.JPG>
+Package pdftex.def Info: ../pics/DSCN2610.JPG used on input line 73.
+(pdftex.def)             Requested size: 281.05421pt x 210.79065pt.
+
+[4] [5 <../pics/DSCN2610.JPG>]
+<../pics/esr_impedance_capacitance.png, id=29, 697.10437pt x 421.69917pt>
+File: ../pics/esr_impedance_capacitance.png Graphic file (type png)
+
+<use ../pics/esr_impedance_capacitance.png>
+Package pdftex.def Info: ../pics/esr_impedance_capacitance.png used on input li
+ne 84.
+(pdftex.def)             Requested size: 348.55133pt x 210.84906pt.
+
+Overfull \hbox (23.33633pt too wide) in paragraph at lines 84--85
+[][] 
+ []
+
+[6 <../pics/esr_impedance_capacitance.png (PNG copy)>]
+Overfull \hbox (48.4497pt too wide) in paragraph at lines 92--92
+[] \OT1/cmtt/m/n/10.95 https://en.wikipedia.org/w/index.php\title=Aluminum_elec
+trolytic 
+ []
+
+[7] <../pics/LC_Filter.png, id=38, 589.4522pt x 206.27063pt>
+File: ../pics/LC_Filter.png Graphic file (type png)
+
+<use ../pics/LC_Filter.png>
+Package pdftex.def Info: ../pics/LC_Filter.png used on input line 119.
+(pdftex.def)             Requested size: 442.08806pt x 154.70258pt.
+
+Overfull \hbox (116.87306pt too wide) in paragraph at lines 119--120
+ [] 
+ []
+
+[8 <../pics/LC_Filter.png>]
+<../pics/DSCN2845.JPG, id=44, 1003.75pt x 752.8125pt>
+File: ../pics/DSCN2845.JPG Graphic file (type jpg)
+
+<use ../pics/DSCN2845.JPG>
+Package pdftex.def Info: ../pics/DSCN2845.JPG used on input line 129.
+(pdftex.def)             Requested size: 401.49289pt x 301.11966pt.
+
+Overfull \hbox (76.2779pt too wide) in paragraph at lines 129--130
+ [] 
+ []
+
+[9 <../pics/DSCN2845.JPG>]
+Underfull \hbox (badness 10000) in paragraph at lines 148--149
+[]\OT1/cmr/m/n/10.95 Various, \OT1/cmr/m/it/10.95 https://www.eevblog.com/forum
+/projects/dreaded-
+ []
+
+
+Underfull \hbox (badness 10000) in paragraph at lines 148--149
+\OT1/cmr/m/n/10.95 also https://www.eevblog.com/forum/beginners/car-engine-
+ []
+
+
+Underfull \hbox (badness 10000) in paragraph at lines 151--152
+[]\OT1/cmr/m/it/10.95 https://partofthething.com/thoughts/building-a-low-pass-f
+ilter-
+ []
+
+
+Underfull \hbox (badness 10000) in paragraph at lines 151--152
+\OT1/cmr/m/it/10.95 to-remove-alternator-whine-in-my-car/\OT1/cmr/m/n/10.95 . P
+ic-ture guide and
+ []
+
+[10] [11] (./26.aux) ) 
+Here is how much of TeX's memory you used:
+ 3568 strings out of 494945
+ 54399 string characters out of 6181032
+ 119070 words of memory out of 5000000
+ 6834 multiletter control sequences out of 15000+600000
+ 10544 words of font info for 37 fonts, out of 8000000 for 9000
+ 14 hyphenation exceptions out of 8191
+ 39i,8n,39p,867b,274s stack positions out of 5000i,500n,10000p,200000b,80000s
+</usr/share/texlive/texmf-dist/fonts/type1/public/amsfont
+s/cm/cmbx10.pfb></usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/c
+mbx12.pfb></usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmr10.p
+fb></usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmr12.pfb></us
+r/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmr6.pfb></usr/share/
+texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmr8.pfb></usr/share/texlive/
+texmf-dist/fonts/type1/public/amsfonts/cm/cmr9.pfb></usr/share/texlive/texmf-di
+st/fonts/type1/public/amsfonts/cm/cmsy10.pfb></usr/share/texlive/texmf-dist/fon
+ts/type1/public/amsfonts/cm/cmti10.pfb></usr/share/texlive/texmf-dist/fonts/typ
+e1/public/amsfonts/cm/cmtt10.pfb>
+Output written on 26.pdf (11 pages, 791797 bytes).
+PDF statistics:
+ 87 PDF objects out of 1000 (max. 8388607)
+ 57 compressed objects within 1 object stream
+ 0 named destinations out of 1000 (max. 500000)
+ 26 words of extra memory for PDF output out of 10000 (max. 10000000)
+

Car_Stereo_Replacement/docs/26.tex

@@ -0,0 +1,154 @@
+\documentclass[11pt]{article}
+%Gummi|065|=)
+\title{\textbf{Car Stereo Replacement}}
+\usepackage{graphicx,caption}
+%\author{Steak Electronics}
+\date{03/20/20}
+
+\usepackage{xcolor}
+\usepackage[vcentering,dvips]{geometry}
+\geometry{papersize={6in,9in},total={4.5in,6.8in}}
+\begin{document}
+\maketitle
+%\tableofcontents
+
+\section{Car Stereo Replacement}
+Replacing a car stereo. I could just go to ebay, and buy a used car stereo, but where's the fun in that? Let's DIY a car stereo from a PCB used as a frontplate, a connector for my vehicle, and an audio amplifier. I'll connect in signal from an audio player.
+\\
+
+\includegraphics[scale=0.4]{../pics/DSCN2180.JPG}
+\captionof{figure}{PCB rev 1}
+
+\subsection{Items Included}
+I thought I would include the following:
+\begin{itemize}
+\item Arduino Nano
+\item Voltage and Gnd Breakout
+\item I2C Display
+\item Voltage Readout (of BAT)
+\item Current Readout (being drawn)
+\item Amplifier ``Lvpin LP-838''
+\end{itemize}
+I also wanted to have the connectors that eurorack and synth designers use for mono audio cables, but the cables turned out too expensive. The current readout didn't work initially, and I haven't gotten to fixing it yet.
+\subsubsection{I2C OLED display}
+Just for fun, I bought an I2C oled display and am going to use it to display something.\footnote{It's an Arduino Uno, you can put almost anything on this.} Notes on this:
+Using the adafruit SSD1306 and GFX library (this procedure is well covered in other places), you can load an example sketch and get it running. First thing to change is to remove the Adafruit logo and replace it with my own. Let's do that.
+
+From https://design.goeszen.com/convert-image-for-oled-display.html
+\begin{verbatim}
+I'm on Linux here and found that the readily-available 
+ImageMagick package will do the trick for you without
+ any scripting. And runs on the CLI! Simple as that:
+
+    convert some_image.png some.image.mono
+\end{verbatim}
+That's efficient. But it didn't really work out. Too much work, I don't need it that bad. Have to convert it to something the c compiler can read. I instead, just deleted their logo. Good enough for now.
+\subsubsection{Internal AVR Temperature Sensor}
+
+I setup the code to read from the internal temp sensor on the duino. However there is also this:
+
+https://thecavepearlproject.org/2019/02/25/no-parts-temperature-measurement-with-arduino-pro-mini-to-0-005c-or-better/
+
+This would be something to do for more resolution. The built in sensor is not very good, so this above link would be great. Hack a day also covers it. 
+
+\subsection{Wiring Pinout is wrong on Internet - Cable has labels}
+I looked at the picture I have detailing the pinout of my car connector (Delco Delphi radio wiring diagram.jpg in resources). It's close, but not 100\% correct. I found that the cable itself has small text labels on each wire which explain which everything does. I didn't notice earlier, as I didn't look close enough (and no one mentioned this).
+
+\subsection{Arduino VReg Blowout}
+I had a knock off Arduino Nano, and the vreg blew out. I have some other vregs to replace it. I didn't have this problem with an Uno that I use as a ceiling dome light. Although that one is not left on as long, usually. 
+
+\subsection{Amplifier}
+The amplifier I used is one of the cheapest avialable on ebay. I'm not proud. I'm poor. I had to take it apart, and reseat the amplifier ICs as the tab was not making contact with the chassis for one of them. I also added thermal paste. This amp is underpowered for my car, and may need replacing. It gets a bit hot.\footnote{This was later solved via using series low impedance caps on the output (coupling amp to speakers).}
+
+Some other issues with this amplifier are that the output connectors can get pushed back, there is only one output connector option, and it must run on battery power, as a 12V 1A or 2A will not power it. Finally, there is a 6V DC bias on output. No output audio isolation, which means you get car noise.
+
+\subsection{AC Audio Coupling to Remove DC Noise from Auto}
+I had some fun with this one. Many videos on this in the video folder. I started with the speakers being directly fed by the amplifier. This worked, but there was some noise coming through. Cars are noisy, this is not surprising. I would've preferred the amplifier to isolate the outputs, but no luck... At this point, I considered two options to block DC and allow AC. 1) Use a transformer. 2) Use capacitors.\footnote{A third option would've been to use a second set of batteries, but that would be laborious.}
+
+\subsubsection{Ground Isolator}
+I had been given a Ground isolator, which was two small transformers on a pcb intended to pass audio from a car powered signal source into the car speakers. I tried this isolator on the output of the speakers, and while it worked, the volume was lower, and it was impractical. I knew as soon as I heard the volume, that the issue was an impedance matching problem. The transformers were too small. They were intended for signal sources, not amplifier outputs. Onto option \#2.
+\\
+
+\begin{center}
+\includegraphics[scale=0.35]{../pics/DSCN2610.JPG}
+\captionof{figure}{Ground Loop Isolator.}
+\end{center}
+\subsubsection{Capacitor Audio Coupling}
+My initial thoughts here were: ``Let's be careful and use non polarized caps''. I bought some 0.22uf and 0.022uf polyester film capacitors at Electronics Plus, the local radioshack replacement, and tried them. No sound. After adjusting the connectors on the amp (which were admittedly loose - it's easy to push them back on the amplifier if you are not careful) I found that the capacitors didn't work. One problem was evident in the oscope. I only used one capacitor on the + output of the speaker amp, but the Amp biases the signal 6 volts. So I needed two. After that was resolved, the signal came through on the output of the capacitor, as viewed on the scope, however there was no sound output. I tried the safe way. It's time to break some rules. 
+
+I grabbed some 1uf (electrolytic polarized) caps I had, and tried these. Again, no sound. Not giving up, I grabbed some 1000uf 'lytics, and tried once more. Now it worked.
+
+\subsubsection{Impedance / ESR of capacitors failing to pass enough power of signal}
+Capacitors are rated for impedance. Some data sheets also call this ESR, it appears after a quick look. It's either in there as impedance or ESR. It's not initially an issue if you are using the capacitor as a DC reservoir, but if you use it in an AC coupling situation then things get interesting. A high impedance, or ESR will block what a low one won't. In this example, it's as simple as the Amplfier either being able to power a speaker or not. Higher capacity caps will have lower impedance. See the picture. Other brands put impedance in a graph, or just call it impedance. 
+
+\includegraphics[scale=0.5]{../pics/esr_impedance_capacitance.png}
+\captionof{figure}{Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.}
+
+\subsubsection{Wikipedia on Impedance}
+
+\emph{In general, a capacitor is seen as a storage component for electric energy. But this is only one capacitor function. A capacitor can also act as an AC resistor. Especially aluminum electrolytic capacitors are used in many applications as a decoupling capacitors to filter or bypass undesired biased AC frequencies to the ground or for capacitive coupling of audio AC signals. Then the dielectric is used only for blocking DC. For such applications the AC resistance, the impedance is as important as the capacitance value. }
+\begin{verbatim} https://en.wikipedia.org/w/index.php\title=Aluminum_electrolytic
+_capacitor&oldid=940281525
+\end{verbatim}
+Essentially, what I learned today.
+
+\subsection{DIY Amp}
+I was flipping through Practical Electronics for Inventors\cite{Scherz}(page 959), when I came across an audio amplifier. He also gives one at the chapter on Semiconductors (pg. 467), although the former is more detailed. With a reasonably simple schematic available, and a high likelihood of it working, I say why not: let's build it up.
+
+I've noticed that the ``Lvpin LP-838'' amplifier I'm using is underpowered for my two front speakers \footnote{Although it seems it would work for one channel, so two of them might be enough. It's rated for 20W, so that is about 15-20W per channel req'd. It works at 20W for both, just that it heats up too much. Multiple ebay sellers have it misquoted at 200W. Just an extra 0, no biggie. Based on all this, it appears each channel of my car speaker needs about 15 watts to be on the safe side. The example schematic is 16 watts. Two should suffice.}, so I will make two of the provided 16 watt amps.
+
+\subsubsection{LM383 is Obsolete}
+That explains why I haven't heard of it. The chip is obsolete. Some sell it on ebay for about \$5 each.
+
+As a different route, could I use some other power amplifier op amp, with the same pinout? Hm... Aha, the LM1875 has the same pinout. Let's use that.\footnote{How did I find this? I searched Digikey for the LM383 sold by rochester, noted it was it the category of Linear - Amplifiers - Audio, chose that, then searched for everything in the same package (TO220-5). Came right up. If this hadn't worked, I would've wanted to try other sites: Farnells, Mouser, etc...}
+
+Will it work with the same schematic? Questionable. May still need to buy a LM383, along with the LM1875, as backup. I might also try a generic power op amp.
+
+Amplfiers are the expensive bom item here.
+
+\subsection{Noise remains with Speaker Isolation}
+I've isolated the speakers from DC with the caps, but noise remains. My next idea was a DC-DC isolated supply. But, I found two threads on eevblog forums\cite{eevblog}, and they recommend a power line filter (they also mention the isolated supply). A filter with a coil and cap (2200uf even low enough) I can quickly build up.
+
+I also want to fix up my portable CRO, I obtained the other day. That needs batteries.
+
+One thing I noticed, is that the amplifier seems to no longer heat up, since the caps were added. Perhaps the DC bias was the cause. I need to confirm this.
+
+I was able to pull an 16.5V transformer from industrial equipment, so let's try this filter:
+
+\begin{center}
+\includegraphics[scale=0.75]{../pics/LC_Filter.png}
+\captionof{figure}{This picture was more difficult to download than it should've been. Spent 3 minutes on this. At least its not a discourse javascript pile of trash.} 
+\end{center}
+
+\subsection{Low Pass Filter to remove Alternator Hum}
+I have built the Low Pass Filter consisting of a 120 to 16V AC transformer and a 2200uf Cap (LC filter). I tested it on my signal gen, and it works quite well. No AC ripple comes through. I tested it in the car, and success - there is no more alternator hum. However...
+
+There is still some noise on the speakers. It is not audible. I can't hear it, but I can feel my ears get sensitive after listening for a song or two. There must be something else getting through that is causing my ears to become sensitive. Either that, or I was not in the mood to listen to my stereo. See the picture of the filter below.
+
+\begin{center}
+\includegraphics[scale=0.4]{../pics/DSCN2845.JPG}
+\captionof{figure}{Fused supply from 12V car battery goes into the female barrel jack, into and out the secondary of the transformer leads. The primary is left floating. There are 2 1000uf 20\% 25V electrolytics after the inductor. Eliminates all alternator hum. Remember that as men, we are in the business of making tools. I have made it a goal to create perf board prototypes, and usable electronic devices, such as this LC filter. This is modular (via barrel plugs) and sturdy enough that I can use it to filter any power supply.}
+\end{center}
+
+\subsection{The story so far}
+So far I have found the following:
+\begin{itemize}
+\item By using electrolytic caps in series to block DC Bias output on the amplifier audio, I reduced unnecessary power dissipation on the amp (doesn't heat up anymore)
+  \item By putting an LC (AC) filter on the 12V input, I was able to block alternator noise.
+\end{itemize}
+I have yet to consider this project done. I suspect some noise still on the audio output. It must be coupled from the power supply.
+
+\subsection{References}
+\begin{thebibliography}{99}
+\bibitem{Scherz}
+  Paul Scherz, and Simon Monk,
+  \emph{Practical Electronics for Inventors}, fourth edition - 2016, McGraw Hill.
+
+\bibitem{eevblog}
+  Various, \emph{https://www.eevblog.com/forum/projects/dreaded-alternator-whine-in-car-stereo/25/} Retrieved 2020-02-21. see also https://www.eevblog.com/forum/beginners/car-engine-signal-interference-with-cell-phone/
+
+\bibitem{partofthe}
+  \emph{https://partofthething.com/thoughts/building-a-low-pass-filter-to-remove-alternator-whine-in-my-car/}. Picture guide and showing basic build in project box. Eevblog users mention you may be able to use the secondary of a transformer, to avoid building the coil.
+  \end{thebibliography}
+
+\end{document}

Car_Stereo_Replacement/docs/26.tex~

@@ -0,0 +1,154 @@
+\documentclass[11pt]{article}
+%Gummi|065|=)
+\title{\textbf{Car Stereo Replacement}}
+\usepackage{graphicx,caption}
+%\author{Steak Electronics}
+\date{03/20/20}
+
+\usepackage{xcolor}
+\usepackage[vcentering,dvips]{geometry}
+\geometry{papersize={6in,9in},total={4.5in,6.8in}}
+\begin{document}
+\maketitle
+%\tableofcontents
+
+\section{Car Stereo Replacement}
+Replacing a car stereo. I could just go to ebay, and buy a used car stereo, but where's the fun in that? Let's DIY a car stereo from a PCB used as a frontplate, a connector for my vehicle, and an audio amplifier. I'll connect in signal from an audio player.
+\\
+
+\includegraphics[scale=0.4]{../pics/DSCN2180.JPG}
+\captionof{figure}{PCB rev 1}
+
+\subsection{Items Included}
+I thought I would include the following:
+\begin{itemize}
+\item Arduino Nano
+\item Voltage and Gnd Breakout
+\item I2C Display
+\item Voltage Readout (of BAT)
+\item Current Readout (being drawn)
+\item Amplifier ``Lvpin LP-838''
+\end{itemize}
+I also wanted to have the connectors that eurorack and synth designers use for mono audio cables, but the cables turned out too expensive. The current readout didn't work initially, and I haven't gotten to fixing it yet.
+\subsubsection{I2C OLED display}
+Just for fun, I bought an I2C oled display and am going to use it to display something.\footnote{It's an Arduino Uno, you can put almost anything on this.} Notes on this:
+Using the adafruit SSD1306 and GFX library (this procedure is well covered in other places), you can load an example sketch and get it running. First thing to change is to remove the Adafruit logo and replace it with my own. Let's do that.
+
+From https://design.goeszen.com/convert-image-for-oled-display.html
+\begin{verbatim}
+I'm on Linux here and found that the readily-available 
+ImageMagick package will do the trick for you without
+ any scripting. And runs on the CLI! Simple as that:
+
+    convert some_image.png some.image.mono
+\end{verbatim}
+That's efficient. But it didn't really work out. Too much work, I don't need it that bad. Have to convert it to something the c compiler can read. I instead, just deleted their logo. Good enough for now.
+\subsubsection{Internal AVR Temperature Sensor}
+
+I setup the code to read from the internal temp sensor on the duino. However there is also this:
+
+https://thecavepearlproject.org/2019/02/25/no-parts-temperature-measurement-with-arduino-pro-mini-to-0-005c-or-better/
+
+This would be something to do for more resolution. The built in sensor is not very good, so this above link would be great. Hack a day also covers it. 
+
+\subsection{Wiring Pinout is wrong on Internet - Cable has labels}
+I looked at the picture I have detailing the pinout of my car connector (Delco Delphi radio wiring diagram.jpg in resources). It's close, but not 100\% correct. I found that the cable itself has small text labels on each wire which explain which everything does. I didn't notice earlier, as I didn't look close enough (and no one mentioned this).
+
+\subsection{Arduino VReg Blowout}
+I had a knock off Arduino Nano, and the vreg blew out. I have some other vregs to replace it. I didn't have this problem with an Uno that I use as a ceiling dome light. Although that one is not left on as long, usually. 
+
+\subsection{Amplifier}
+The amplifier I used is one of the cheapest avialable on ebay. I'm not proud. I'm poor. I had to take it apart, and reseat the amplifier ICs as the tab was not making contact with the chassis for one of them. I also added thermal paste. This amp is underpowered for my car, and may need replacing. It gets a bit hot.\footnote{This was later solved via using series low impedance caps on the output (coupling amp to speakers).}
+
+Some other issues with this amplifier are that the output connectors can get pushed back, there is only one output connector option, and it must run on battery power, as a 12V 1A or 2A will not power it. Finally, there is a 6V DC bias on output. No output audio isolation, which means you get car noise.
+
+\subsection{AC Audio Coupling to Remove DC Noise from Auto}
+I had some fun with this one. Many videos on this in the video folder. I started with the speakers being directly fed by the amplifier. This worked, but there was some noise coming through. Cars are noisy, this is not surprising. I would've preferred the amplifier to isolate the outputs, but no luck... At this point, I considered two options to block DC and allow AC. 1) Use a transformer. 2) Use capacitors.\footnote{A third option would've been to use a second set of batteries, but that would be laborious.}
+
+\subsubsection{Ground Isolator}
+I had been given a Ground isolator, which was two small transformers on a pcb intended to pass audio from a car powered signal source into the car speakers. I tried this isolator on the output of the speakers, and while it worked, the volume was lower, and it was impractical. I knew as soon as I heard the volume, that the issue was an impedance matching problem. The transformers were too small. They were intended for signal sources, not amplifier outputs. Onto option \#2.
+\\
+
+\begin{center}
+\includegraphics[scale=0.35]{../pics/DSCN2610.JPG}
+\captionof{figure}{Ground Loop Isolator.}
+\end{center}
+\subsubsection{Capacitor Audio Coupling}
+My initial thoughts here were: ``Let's be careful and use non polarized caps''. I bought some 0.22uf and 0.022uf polyester film capacitors at Electronics Plus, the local radioshack replacement, and tried them. No sound. After adjusting the connectors on the amp (which were admittedly loose - it's easy to push them back on the amplifier if you are not careful) I found that the capacitors didn't work. One problem was evident in the oscope. I only used one capacitor on the + output of the speaker amp, but the Amp biases the signal 6 volts. So I needed two. After that was resolved, the signal came through on the output of the capacitor, as viewed on the scope, however there was no sound output. I tried the safe way. It's time to break some rules. 
+
+I grabbed some 1uf (electrolytic polarized) caps I had, and tried these. Again, no sound. Not giving up, I grabbed some 1000uf 'lytics, and tried once more. Now it worked.
+
+\subsubsection{Impedance / ESR of capacitors failing to pass enough power of signal}
+Capacitors are rated for impedance. Some data sheets also call this ESR, it appears after a quick look. It's either in there as impedance or ESR. It's not initially an issue if you are using the capacitor as a DC reservoir, but if you use it in an AC coupling situation then things get interesting. A high impedance, or ESR will block what a low one won't. In this example, it's as simple as the Amplfier either being able to power a speaker or not. Higher capacity caps will have lower impedance. See the picture. Other brands put impedance in a graph, or just call it impedance. 
+
+\includegraphics[scale=0.5]{../pics/esr_impedance_capacitance.png}
+\captionof{figure}{Notice how impedance jumps very fast with a 1uf cap, compared to the higher values. Additionally, different brands will have different impedances for a similar value cap.}
+
+\subsubsection{Wikipedia on Impedance}
+
+\emph{In general, a capacitor is seen as a storage component for electric energy. But this is only one capacitor function. A capacitor can also act as an AC resistor. Especially aluminum electrolytic capacitors are used in many applications as a decoupling capacitors to filter or bypass undesired biased AC frequencies to the ground or for capacitive coupling of audio AC signals. Then the dielectric is used only for blocking DC. For such applications the AC resistance, the impedance is as important as the capacitance value. }
+\begin{verbatim} https://en.wikipedia.org/w/index.php\title=Aluminum_electrolytic
+_capacitor&oldid=940281525
+\end{verbatim}
+Essentially, what I learned today.
+
+\subsection{DIY Amp}
+I was flipping through Practical Electronics for Inventors\cite{Scherz}(page 959), when I came across an audio amplifier. He also gives one at the chapter on Semiconductors (pg. 467), although the former is more detailed. With a reasonably simple schematic available, and a high likelihood of it working, I say why not: let's build it up.
+
+I've noticed that the ``Lvpin LP-838'' amplifier I'm using is underpowered for my two front speakers \footnote{Although it seems it would work for one channel, so two of them might be enough. It's rated for 20W, so that is about 15-20W per channel req'd. It works at 20W for both, just that it heats up too much. Multiple ebay sellers have it misquoted at 200W. Just an extra 0, no biggie. Based on all this, it appears each channel of my car speaker needs about 15 watts to be on the safe side. The example schematic is 16 watts. Two should suffice.}, so I will make two of the provided 16 watt amps.
+
+\subsubsection{LM383 is Obsolete}
+That explains why I haven't heard of it. The chip is obsolete. Some sell it on ebay for about \$5 each.
+
+As a different route, could I use some other power amplifier op amp, with the same pinout? Hm... Aha, the LM1875 has the same pinout. Let's use that.\footnote{How did I find this? I searched Digikey for the LM383 sold by rochester, noted it was it the category of Linear - Amplifiers - Audio, chose that, then searched for everything in the same package (TO220-5). Came right up. If this hadn't worked, I would've wanted to try other sites: Farnells, Mouser, etc...}
+
+Will it work with the same schematic? Questionable. May still need to buy a LM383, along with the LM1875, as backup. I might also try a generic power op amp.
+
+Amplfiers are the expensive bom item here.
+
+\subsection{Noise remains with Speaker Isolation}
+I've isolated the speakers from DC with the caps, but noise remains. My next idea was a DC-DC isolated supply. But, I found two threads on eevblog forums\cite{eevblog}, and they recommend a power line filter (they also mention the isolated supply). A filter with a coil and cap (2200uf even low enough) I can quickly build up.
+
+I also want to fix up my portable CRO, I obtained the other day. That needs batteries.
+
+One thing I noticed, is that the amplifier seems to no longer heat up, since the caps were added. Perhaps the DC bias was the cause. I need to confirm this.
+
+I was able to pull an 16.5V transformer from industrial equipment, so let's try this filter:
+
+\begin{center}
+\includegraphics[scale=0.75]{../pics/LC_Filter.png}
+\captionof{figure}{This picture was more difficult to download than it should've been. Spent 3 minutes on this. At least its not a discourse javascript pile of trash.} 
+\end{center}
+
+\subsection{Low Pass Filter to remove Alternator Hum}
+I have built the Low Pass Filter consisting of a 120 to 16V AC transformer and a 2200uf Cap (LC filter). I tested it on my signal gen, and it works quite well. No AC ripple comes through. I tested it in the car, and success - there is no more alternator hum. However...
+
+There is still some noise on the speakers. It is not audible. I can't hear it, but I can feel my ears get sensitive after listening for a song or two. There must be something else getting through that is causing my ears to become sensitive. Either that, or I was not in the mood to listen to my stereo. See the picture of the filter below.
+
+\begin{center}
+\includegraphics[scale=0.4]{../pics/DSCN2845.JPG}
+\captionof{figure}{Fused supply from 12V car battery goes into the female barrel jack, into and out the secondary of the transformer leads. The primary is left floating. There is 2000uf 20\% 25V electrolytics after the inductor. Eliminates all alternator hum. Remember that as men, we are in the business of making tools. I have made it a goal to create perf board prototypes, and usable electronic devices, such as this LC filter. This is modular (via barrel plugs) and sturdy enough that I can use it to filter any power supply.}
+\end{center}
+
+\subsection{The story so far}
+So far I have found the following:
+\begin{itemize}
+\item By using electrolytic caps in series to block DC Bias output on the amplifier audio, I reduced unnecessary power dissipation on the amp (doesn't heat up anymore)
+  \item By putting an LC (AC) filter on the 12V input, I was able to block alternator noise.
+\end{itemize}
+I have yet to consider this project done. I suspect some noise still on the audio output. It must be coupled from the power supply.
+
+\subsection{References}
+\begin{thebibliography}{99}
+\bibitem{Scherz}
+  Paul Scherz, and Simon Monk,
+  \emph{Practical Electronics for Inventors}, fourth edition - 2016, McGraw Hill.
+
+\bibitem{eevblog}
+  Various, \emph{https://www.eevblog.com/forum/projects/dreaded-alternator-whine-in-car-stereo/25/} Retrieved 2020-02-21. see also https://www.eevblog.com/forum/beginners/car-engine-signal-interference-with-cell-phone/
+
+\bibitem{partofthe}
+  \emph{https://partofthething.com/thoughts/building-a-low-pass-filter-to-remove-alternator-whine-in-my-car/}. Picture guide and showing basic build in project box. Eevblog users mention you may be able to use the secondary of a transformer, to avoid building the coil.
+  \end{thebibliography}
+
+\end{document}

Car_Stereo_Replacement/docs/3.aux

@@ -3,3 +3,4 @@
 \@writefile{toc}{\contentsline {section}{\numberline {2}Work Log}{1}}
 \@writefile{toc}{\contentsline {subsection}{\numberline {2.1}I2C OLED display}{1}}
 \@writefile{toc}{\contentsline {subsection}{\numberline {2.2}Internal AVR Temperature Sensor}{1}}
+\@writefile{toc}{\contentsline {section}{\numberline {3}Wiring Pinout is wrong on Internet}{2}}

Car_Stereo_Replacement/docs/3.log

@@ -1,4 +1,4 @@
-This is pdfTeX, Version 3.14159265-2.6-1.40.17 (TeX Live 2016/Debian) (preloaded format=pdflatex 2019.8.17)  28 OCT 2019 01:39
+This is pdfTeX, Version 3.14159265-2.6-1.40.17 (TeX Live 2016/Debian) (preloaded format=pdflatex 2019.8.17)  7 JAN 2020 11:38
 entering extended mode
  restricted \write18 enabled.
  %&-line parsing enabled.
@@ -61,7 +61,7 @@ ature-measurement-
 
 [1
 
-{/var/lib/texmf/fonts/map/pdftex/updmap/pdftex.map}] (./3.aux) ) 
+{/var/lib/texmf/fonts/map/pdftex/updmap/pdftex.map}] [2] (./3.aux) ) 
 Here is how much of TeX's memory you used:
  233 strings out of 494945
  2763 string characters out of 6181032
@@ -69,16 +69,16 @@ Here is how much of TeX's memory you used:
  3602 multiletter control sequences out of 15000+600000
  8362 words of font info for 30 fonts, out of 8000000 for 9000
  14 hyphenation exceptions out of 8191
- 21i,6n,19p,352b,187s stack positions out of 5000i,500n,10000p,200000b,80000s
-</usr/share/tex
-live/texmf-dist/fonts/type1/public/amsfonts/cm/cmbx12.pfb></usr/share/texlive/t
-exmf-dist/fonts/type1/public/amsfonts/cm/cmr10.pfb></usr/share/texlive/texmf-di
-st/fonts/type1/public/amsfonts/cm/cmr12.pfb></usr/share/texlive/texmf-dist/font
-s/type1/public/amsfonts/cm/cmtt10.pfb>
-Output written on 3.pdf (1 page, 60713 bytes).
+ 21i,6n,19p,437b,187s stack positions out of 5000i,500n,10000p,200000b,80000s
+</usr/share
+/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmbx12.pfb></usr/share/texli
+ve/texmf-dist/fonts/type1/public/amsfonts/cm/cmr10.pfb></usr/share/texlive/texm
+f-dist/fonts/type1/public/amsfonts/cm/cmr12.pfb></usr/share/texlive/texmf-dist/
+fonts/type1/public/amsfonts/cm/cmtt10.pfb>
+Output written on 3.pdf (2 pages, 61664 bytes).
 PDF statistics:
- 24 PDF objects out of 1000 (max. 8388607)
- 16 compressed objects within 1 object stream
+ 27 PDF objects out of 1000 (max. 8388607)
+ 18 compressed objects within 1 object stream
  0 named destinations out of 1000 (max. 500000)
  1 words of extra memory for PDF output out of 10000 (max. 10000000)
 

Car_Stereo_Replacement/docs/3.tex

@@ -29,7 +29,8 @@ https://thecavepearlproject.org/2019/02/25/no-parts-temperature-measurement-with
 
 This would be something to do for more resolution. The built in sensor is not very good, so this above link would be great. Hack a day also covers it. 
 
-
+\section{Wiring Pinout is wrong on Internet}
+I looked at the picture I have detailing the pinout (Delco Delphi radio wiring diagram.jpg in resources). It's close, but not exact to the cable. I found that the cable has small text labels on each wire which explain which everything does. I didn't notice earlier, as I didn't look close enough (and no one mentioned this).
 
 
 

Car_Stereo_Replacement/docs/4.aux

@@ -0,0 +1,11 @@
+\relax 
+\@writefile{toc}{\contentsline {section}{\numberline {1}Overview}{1}}
+\@writefile{toc}{\contentsline {section}{\numberline {2}Work Log}{1}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {2.1}I2C OLED display}{1}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {2.2}Internal AVR Temperature Sensor}{1}}
+\@writefile{toc}{\contentsline {section}{\numberline {3}Wiring Pinout is wrong on Internet - Cable has labels}{2}}
+\@writefile{toc}{\contentsline {section}{\numberline {4}Arduino VReg Blowout}{2}}
+\@writefile{toc}{\contentsline {section}{\numberline {5}AC Audio Coupling to Remove DC Noise from Auto}{2}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {5.1}Ground Isolator}{2}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {5.2}Capacitor Audio Coupling}{2}}
+\@writefile{toc}{\contentsline {subsubsection}{\numberline {5.2.1}Impedance / ESR of capacitors failing to pass enough power of signal}{3}}

Car_Stereo_Replacement/docs/4.log

@@ -0,0 +1,90 @@
+This is pdfTeX, Version 3.14159265-2.6-1.40.17 (TeX Live 2016/Debian) (preloaded format=pdflatex 2019.8.17)  14 FEB 2020 02:09
+entering extended mode
+ restricted \write18 enabled.
+ %&-line parsing enabled.
+**/home/layoutdev/Desktop/code/documentation_general/Electronics_Projects_2019/
+Car_Stereo_Replacement/docs/4.tex
+
+(/home/layoutdev/Desktop/code/documentation_general/Electronics_Projects_2019/C
+ar_Stereo_Replacement/docs/4.tex
+LaTeX2e <2017/01/01> patch level 3
+Babel <3.9r> and hyphenation patterns for 3 language(s) loaded.
+(/usr/share/texlive/texmf-dist/tex/latex/base/article.cls
+Document Class: article 2014/09/29 v1.4h Standard LaTeX document class
+(/usr/share/texlive/texmf-dist/tex/latex/base/size11.clo
+File: size11.clo 2014/09/29 v1.4h Standard LaTeX file (size option)
+)
+\c@part=\count79
+\c@section=\count80
+\c@subsection=\count81
+\c@subsubsection=\count82
+\c@paragraph=\count83
+\c@subparagraph=\count84
+\c@figure=\count85
+\c@table=\count86
+\abovecaptionskip=\skip41
+\belowcaptionskip=\skip42
+\bibindent=\dimen102
+) (./4.aux)
+\openout1 = `4.aux'.
+
+LaTeX Font Info:    Checking defaults for OML/cmm/m/it on input line 6.
+LaTeX Font Info:    ... okay on input line 6.
+LaTeX Font Info:    Checking defaults for T1/cmr/m/n on input line 6.
+LaTeX Font Info:    ... okay on input line 6.
+LaTeX Font Info:    Checking defaults for OT1/cmr/m/n on input line 6.
+LaTeX Font Info:    ... okay on input line 6.
+LaTeX Font Info:    Checking defaults for OMS/cmsy/m/n on input line 6.
+LaTeX Font Info:    ... okay on input line 6.
+LaTeX Font Info:    Checking defaults for OMX/cmex/m/n on input line 6.
+LaTeX Font Info:    ... okay on input line 6.
+LaTeX Font Info:    Checking defaults for U/cmr/m/n on input line 6.
+LaTeX Font Info:    ... okay on input line 6.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <12> on input line 8.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <8> on input line 8.
+LaTeX Font Info:    External font `cmex10' loaded for size
+(Font)              <6> on input line 8.
+
+Overfull \hbox (559.79004pt too wide) in paragraph at lines 22--22
+[]\OT1/cmtt/m/n/10.95 I'm on Linux here and found that the readily-available Im
+ageMagick package will do the trick for you without any scripting. And runs on 
+the CLI! Simple as that:[] 
+ []
+
+
+Overfull \hbox (45.51251pt too wide) in paragraph at lines 28--29
+[]\OT1/cmr/m/n/10.95 https://thecavepearlproject.org/2019/02/25/no-parts-temper
+ature-measurement-
+ []
+
+[1
+
+{/var/lib/texmf/fonts/map/pdftex/updmap/pdftex.map}] [2]
+Overfull \hbox (0.30136pt too wide) in paragraph at lines 49--49
+[]\OT1/cmr/bx/n/10.95 Impedance / ESR of ca-pac-i-tors fail-ing to pass enough 
+power
+ []
+
+[3] (./4.aux) ) 
+Here is how much of TeX's memory you used:
+ 235 strings out of 494945
+ 2787 string characters out of 6181032
+ 50564 words of memory out of 5000000
+ 3603 multiletter control sequences out of 15000+600000
+ 8670 words of font info for 31 fonts, out of 8000000 for 9000
+ 14 hyphenation exceptions out of 8191
+ 21i,6n,19p,842b,187s stack positions out of 5000i,500n,10000p,200000b,80000s
+</usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cm
+bx10.pfb></usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmbx12.p
+fb></usr/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmr10.pfb></us
+r/share/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmr12.pfb></usr/share
+/texlive/texmf-dist/fonts/type1/public/amsfonts/cm/cmtt10.pfb>
+Output written on 4.pdf (3 pages, 81896 bytes).
+PDF statistics:
+ 34 PDF objects out of 1000 (max. 8388607)
+ 23 compressed objects within 1 object stream
+ 0 named destinations out of 1000 (max. 500000)
+ 1 words of extra memory for PDF output out of 10000 (max. 10000000)
+

Car_Stereo_Replacement/docs/4.tex

@@ -0,0 +1,55 @@
+\documentclass[11pt]{article}
+%Gummi|065|=)
+\title{\textbf{Car Stereo Replacement}}
+\author{Steak Electronics}
+\date{10/27/19}
+\begin{document}
+
+\maketitle
+
+\section{Overview}
+Replacing a car stereo.
+\section{Work Log}
+\subsection{I2C OLED display}
+Just for fun, I bought an I2C oled display and are going to use it to display something. Notes on this:
+Using the adafruit SSD1306 and GFX library (this procedure is well covered in other places), you can load an example sketch and get it running. First thing to change is to remove the Adafruit logo and replace it with my own. Let's do that.
+
+From https://design.goeszen.com/convert-image-for-oled-display.html
+\begin{verbatim}
+I'm on Linux here and found that the readily-available ImageMagick package will do the trick for you without any scripting. And runs on the CLI! Simple as that:
+
+    convert some_image.png some.image.mono
+\end{verbatim}
+That's efficient. But it didn't really work out. Too much work, I don't need it that bad. Have to convert it to something the c compiler can read.
+\subsection{Internal AVR Temperature Sensor}
+
+For starters I setup the code to read from the internal temp sensor on the duino. However there is also this:
+
+https://thecavepearlproject.org/2019/02/25/no-parts-temperature-measurement-with-arduino-pro-mini-to-0-005c-or-better/
+
+This would be something to do for more resolution. The built in sensor is not very good, so this above link would be great. Hack a day also covers it. 
+
+\section{Wiring Pinout is wrong on Internet - Cable has labels}
+I looked at the picture I have detailing the pinout (Delco Delphi radio wiring diagram.jpg in resources). It's close, but not 100\% correct. I found that the cable itself has small text labels on each wire which explain which everything does. I didn't notice earlier, as I didn't look close enough (and no one mentioned this).
+
+\section{Arduino VReg Blowout}
+I had a knock off Arduino Nano, and the vreg blew out. I have some other vregs to replace it.
+
+\section{AC Audio Coupling to Remove DC Noise from Auto}
+I had some fun with this one. Many videos on this. I started with the speakers being directly fed by the amplifier. This worked, but there was some noise coming through. Cars are noisy, this is not surprising. I would've preferred the amplifier to isolate the outputs, but no luck... At this point, I considered two options. 1) Use a transformer to block DC. 2) Use capacitors to couple AC.
+
+\subsection{Ground Isolator}
+I had been given a Ground isolator, which was two small transformers on a pcb intended to pass audio from a car powered signal source into the car speakers. I tried this isolator on the output of the speakers, and while it worked, the volume was lower, and it was impractical. I knew as soon as I heard the volume, that the issue was an impedance matching problem. The transformers were too small. They were intended for signal sources, not amplifier outputs. Onto option \#2.
+
+\subsection{Capacitor Audio Coupling}
+My initial thoughts here were: ``Let's be careful and use non polarized caps''. I bought some 0.22uf and 0.022uf polyester film capacitors at Electronics Plus, the local radioshack replacement, and tried them. No sound. After adjusting the connectors (which were admittedly loose - it's easy to push them back on the amplifier if you are not careful) I found that the capacitors didn't work. There were two issues. 1) I only used one capacitor on the + output of the speaker amp, but the Amp biases the signal 6 volts. So I needed two. After that was resolved, the signal came through on the output of the capacitor, as viewed on the scope, however there was no sound output. I tried the safe way. It's time to break some rules. 
+
+I grabbed some 1uf caps I had, and tried these. Again, no sound. Not giving up, I grabbed some 1000uf caps, and tried once more. Now I had sound.
+
+\subsubsection{Impedance / ESR of capacitors failing to pass enough power of signal}
+Capacitors are rated for impedance. Some data sheets also call this ESR. It's not an issue in this case, if you are using the capacitor as a DC reservoir, but if you use it in an AC coupling situation then things get interesting. A high impedance, or ESR will block what a low one won't. In this example, it's as simple as the Amplfier either being able to power a speaker or not. Higher capacity caps will have lower impedance. See the picture.
+
+
+
+
+\end{document}

Car_Stereo_Replacement/docs/4.tex~

@@ -0,0 +1,37 @@
+\documentclass[11pt]{article}
+%Gummi|065|=)
+\title{\textbf{Car Stereo Replacement}}
+\author{Steak Electronics}
+\date{10/27/19}
+\begin{document}
+
+\maketitle
+
+\section{Overview}
+Replacing a car stereo.
+\section{Work Log}
+\subsection{I2C OLED display}
+Just for fun, I bought an I2C oled display and are going to use it to display something. Notes on this:
+Using the adafruit SSD1306 and GFX library (this procedure is well covered in other places), you can load an example sketch and get it running. First thing to change is to remove the Adafruit logo and replace it with my own. Let's do that.
+
+From https://design.goeszen.com/convert-image-for-oled-display.html
+\begin{verbatim}
+I'm on Linux here and found that the readily-available ImageMagick package will do the trick for you without any scripting. And runs on the CLI! Simple as that:
+
+    convert some_image.png some.image.mono
+\end{verbatim}
+That's efficient. But it didn't really work out. Too much work, I don't need it that bad. Have to convert it to something the c compiler can read.
+\subsection{Internal AVR Temperature Sensor}
+
+For starters I setup the code to read from the internal temp sensor on the duino. However there is also this:
+
+https://thecavepearlproject.org/2019/02/25/no-parts-temperature-measurement-with-arduino-pro-mini-to-0-005c-or-better/
+
+This would be something to do for more resolution. The built in sensor is not very good, so this above link would be great. Hack a day also covers it. 
+
+\section{Wiring Pinout is wrong on Internet}
+I looked at the picture I have detailing the pinout (Delco Delphi radio wiring diagram.jpg in resources). It's close, but not exact to the cable. I found that the cable has small text labels on each wire which explain which everything does. I didn't notice earlier, as I didn't look close enough (and no one mentioned this).
+
+
+
+\end{document}