auto match III spectrophotometer



68000 based micro

 two board construction



sensor board + main CPU board


sensor board has leds soldered on all edges of board
slight nuisance to repair

must cut all then resolder

ics
Colour Board:
Maxim187ACWE x 2  ADC w/4.096 reference (see resources for why this is used)(SPI)
X77K  (LED drivers) x 5
LT1152 x 2 (op amps connected between adc and) 
LT0412 x 1 (can't find data sheet on this one)
X9241A Renesas digital Potentiometer x 1 (I2C)
OPT301M (Burr Brown / TI).


VDD is 5V+ (colour board)
There is a VREG, and some drivers that are only used for the leds, the 74 series
logic is also for the leds


the FFC connector on bottom of colour board.
Starting at pin 1, with ffc coming towards you

1
2
3 GND
4 VDD
5
6
7
8 CS
9
10
11 SCLK2
12 SCLK1
13 DOUT1
14 DOUT2

CS are common to both MAX187,
These numbers (DOUT1,2 SCLK1,2 should be double checked. I think they are wrong.)
Note that they have ONE CS, and TWO DO. So instead of selecting chip via
the different CS, they simply read both DO at the same time.
I didn't know you could do this. However, it comes at the expense of separate
SCLK lines, which they had to put on the FFC.


Both DOUT are held high by R next to each MAX187



Pinout of Colour Sensor EDIT: I found the data sheet, skip to the next pinout 
(going clockwise with notch as #1, with the pins facing towards you)
1 GND
2 5V/VDD
3
4
5
6
7
8

(with pins below you, top of sensor facing you)(counter clockwise, 1 is one left of notch)
FROM DATASHEET
1 5V+
2 In - 
3 V- 
4 1M ohm Feedback
5 Output    (Goes into 0 ohm resistor, then into LT1152 Op Amp on right side)
6 n/c
7 n/c
8 GND (notch)


LT1154 output to MAX187 adc. 
One (inverting?) Input is from Renesas Digital Pot.
X9241AUS is four 50K.

No one is really using the X9241 online.

http://www.combustory.com/wiki/index.php/Temperature_Controller


The digital pot looks to be to tune the Feedback R of the OPT301. Pin 4. I think...

Could just hack a 50K resistor in there somewhere probably. It has an internal
1M ohm resistor...