During the development of the Xprotolab, I needed to test the I2C protocol sniffer. I thought that one cool way to do it was using a Wii Nunchuk, I would use one Xprotolab as the controller (running a simple program to read the data), and another Xprotolab to sniff the protocol.
This driver was developed for the XMEGA microcontroller.
Download the files here: