Guys,

I've been working this problem for nearly a year now. I've tried Soubie's code with no luck, and the code from this thread isn't working either. I'm using the 18F4620 as the master talking to an 18F2620, the little brother of the 4620 as the slave. I've RTFM to the point I can recite it, and the Errata sheets, and I've tried countless logical, and even illogical options to trying to get it working.

The best I can get so far is the master sends the address byte and the slave accepts it when it matches its own address and ignores addresses not matching its own. When the address matches, the slave sets the Buffer Full and the Interrupt Flags, but for some reason won't send an ACK back to the master (at least that's what this thread's code [and my own polls of the master's ACK flag] are saying). I've made sure to clear all flags as the datasheet clearly directs, and still no luck. If the slave would ACK, the master would send the next byte and so on.

I'm operating both chips on their internal crystal (8 MHz) and using the 4x PLL (= 32MHz). Before you go there, I'm already successfully talking to an I2C real-time clock chip with no problems and I'm saving data to an external I2C EEPROM regularly with no problems. The I2C network is working with the PICs at 32 MHz. I'm on the right pins; I'm using the pull external pull-up resistors...

I've had this exact hardware working in the past when using MikroElektronika Basic, but I'm much happier in PBP. This one problem is holding up the entire project. Trying to get two 18F's to ping-pong data back and forth is a killer.

If someone has even a bit more success than what I've had, please post it and maybe together we can chip away at this challenge.