Implementation of Apple iPod Accessory Protocol (iAP) over UART in Python
Connect the iPod (or iPhone, or iPad) with a 30 pin docking connector via a breakout cable to a USB->UART adapter, or to a UART port on your SBC (not tested yet).
A 500k resistor on pin 21 may be needed. (In my testing it's been working without one)
Important: iPod uses TTL 3.3V serial