Shawn wrote: > I'm trying to otically-isolate the I/O lines of my PIC, but one of them (the > SDA line of the I2C bus) is bi-directional. Can anybody out there give me a If you're just bit-banging the I2C, the easiest way is to use separate port pins for the SDA receive and transmit functions, with separate optoisolators (in opposite directions). Make sure the optoisolator used for SDA transmit is effectively open-collector. I think you'll need to do the same thing on SCL, so you'll need four port pins altogether.