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\title{\textbf{}}
\author{Steak Electronics}
\date{}
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\section{60Hz Divider}}
\subsection{Counting the Hz}
pseudo code goal:
\begin{verbatim}
Using 1Hz signal
Start counting 1MHz every 1Hz
when next cycle is received,
display count
start counting again
\end{verbatim}
That's all the objective is here. Easy with a micro, but goal is to complete using cmos or 74 logic.
4553 x 5
74hct132
1MHz clock (or 6MHz clock), or some variation thereof
jk flip flop
74376 - quad jk flip flop
7476 - jk flip flop
1mhz clk will be main counter,
6 hz or 1 hz will be latch / reset
\subsection{MAX7219 8 digit 7 LED segment Display Driver}
Basic code tested with this was the LedControl arduino library.
\begin{verbatim}
/*
Now we need a LedControl to work with.
***** These pin numbers will probably not work with your hardware *****
pin 12 is connected to the DataIn
pin 11 is connected to the CLK
pin 10 is connected to LOAD
We have only a single MAX72XX.
*/
\end{verbatim}
Some of the lines have to be edited to allow for all digits to be read, and
also to lower intensity of display. I think also a component package (dark
grey clear plastic bag) in front of the leds with intensity 1 is about right.
\subsection{CPLD Programming}
Using the XC9500XL series. This chip has some limitations - which are good.
As you get faster clocks, you need bigger registers to handle parsing the clocks.
bigger registers, use more power.
\subsubsection{6KHz clock}
Due to limitations of the XC9500XL FPGA logic blocks, I ended up limiting the counter registers to 12+1 bits\footnote{Possibly I could use multiple smaller registers in a type of cascade, but let's not bother with that for now. I had 600KHz resolution, until I added the UART out/}, so I have around 6,000 (assuming 60Hz), resolution. With this, I need a 6KHz clock. I could do this with the uno, but let's throw an attiny in there because it's a good tool for this kind of purpose and resolution. It should be able to function as a rough 6KHz timer, easily.
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