Quote Originally Posted by SteveB View Post
Both the EEPROM and the PCF8574A use the I2C communications. At the bottom-right of the schematic you will note two pull up resistors on the lines that connect the I2C bus to the 5 chips.

So, the micro controller will use I2C to address the desired device as needed. EEPROM for storage and retrival of the data. PCF8574A for the actually setting the values for each element of the matrix.

That's the simplified overview.

HTH,
SteveB
Ok, so I am correct in the assumption that the microcontroller is connected to the left of the EEPROM on the schematic? I've been told that this is an intermediate to advanced programming level for the PIC? Is there anything you recommend me reading so I can program this? Or any sites that offer custom program solutions for $$$?