hi

I2C communication is simple,
i can even handle SDA and SCL wit 2 wires in my hands...

u need only 2 (or 3) port bits and some timed outpu for start/stop condition, and serial data shifting, a pullup on both lines, and an open collector driver or open drain BS170 or ULN2803 i use most for this purpos, i have alread written a protokoll subroutine in basic to transfer data from some other microcontroller to an PCF 8574 , took 1 day, , if u need help ask me