iPod Controls
iPod Breakout Board
After bringing up the FM Radio, the iPod was a walk in the park. We found a wiki site nuxx.net with the protocol reverse engineered, and it was as simple as sending serial strings at 8N1 19200 speeds, terminating with a checksum. We wrote up functions to pause, play, and skip songs, and they worked great.
Using a pinout we found at pinouts.ru, we connected to the line level audio out, and fed that through our audio multiplexer and into the amp. We had bought a breakout adapter from Sparkfun which made it easy to wire to the iPod. Our next phase would have been to use the advanced protocol to retrieve song data, but we ran out of time.