vanduino,
About a year ago I made a system that involved many I2C nodes on a single bus. The chips included:
- PCA9539
- LTC2489
- LTC2655
- PCA9541
- plus LCD displays
This was an I2C multiplexed system with up to 16 multiplexers controlling I2C traffic to sub-branches (each sub-branch with many I2C devices).
I used only the first I2C bus, and the Ethernet shield interface.
I got it all to work, but I had to write a bunch of code because the Wire library is essentially broken for all but the most basic i2c transfers (and I believe that it still is).
It's not a matter of "compatible chips". It's a matter of the interaction of the Wire library and the SAM chip hardware (the interface by Arduino was never completed).
Do some searching to find out what I2C modes are not supported (my user name may help, since I'm pretty good at crabbing about it).
Also, the I2C pins are FRAGILE. I cooked my fair share of DUE's by abusing the I2C pins. (Is your DUE running HOT?)
I also recommend this:
There are others (many cheaper) too.
An overall schematic is attached. Do not trust it & confirm everything.
Good luck,
Chris
Schematic Prints.pdf (203 KB)