Cards with symbols act as the physical interface to an iPod Jukebox. The relatively 'closed' platform of the iPod can suddenly become open using an iPodEXT Breakout connector from SeeedStudio in China. It allows access to all 30 pins of an iPhone or iPod.
There 30 pins total on the standard iPod connection. Here are the important ones for basic manipulation of music:
V = iR is basic Ohm’s law. Arduino provides 5V from the USB, standard. Arduino outputs at 0.5 amps. iPod charges at 5V, maximum 1 amp so no resistors are needed.
Hooking up all grounds and 5V from the arduino, the iPod is charging. Tx on iPod (pin 12) to Rx on Arduino (digital pin 0), and Rx on iPod (pin 13) to Tx on Arduino (digital pin 1). Here are the references used to piece together code: