This page will document an automated Flex-Cable tester for the g-2 tracker.
The idea is to automatically verify that there are no shorts or opens in
a flex-cable, given connectors on both ends interfaced to a computer.

* Schematic: [http://ohm.bu.edu/~hazen/G-2/TestBeam_A.pdf TestBeam_A.pdf]

There are a total of 144 pins on a Flexi (64+80 connector pins)
There are ~44 non-GND nets in this design.  We need to be able to drive each
one to logic 0 or 1 from one end of the cable.  The remaining 100 pins need to be measured
as inputs, with a pull-up resistor to sense shorts.  So, we need:

* On the ZIF end:
 * 44 outputs
 * 19 inputs
 * 1 GND
* On the ASDQ end:
 * 79 inputs
 * 1 GND

An ATmega328 provides easily 15 I/O plus I2C and UART (13 on Arduino because of XTAL)
There exist e.g. PCA9555 I/O expanders which connect to I2C and provide 16 extra I/Os.

So on the ZIF end we could use e.g. an ATmega328 (15 I/O) plus (3) PCA9555 giving
a total of exactly 63 I/O which is what is needed.

On the ASDQ end we could use another ATmega328 plus (4) PCA9555.

Alternatively we could build a (otherwise useful) Arduino I/O expander shield with a
lot of I/Os on standard ribbon cable headers and then two boards with the flexi connectors.

See:  
[http://macetech.com/store/index.php?main_page=product_info&cPath=4&products_id=23 Centipede Shield]