I2C

Parameters for the operation of the VFAT board are downloaded to the chip using the I2C protocol.
A good overview of I2C is available on wikipedia

Electrical Characteristics

The I2C specification limits the I2C bus capacitance to 400pF. The cat5e wire specification limits wire capacitance to 50pF/m, so we should be able to push I2C at least 8m. Testing is needed, but by lowering the bus clock and the pull-up resistors a much greater length should be possible.

Stuff to buy

1. Power Supply 2. Gumstix (x2) 3. I2C expanders 4. I2C eproms (for feedback testing) 5. header pins