Lets take a quick look at the Hardware of the IPod Receiver Unit shown on the left of the picture below.
Front and Back of the Receiver circuit board which basically contain a IR Receiver Chip and 8 Pin IC.
An up close look at the single IC on the circuit board
Which we find is an HS108N program once micro-controller which presumably has the task of converting standard RC5 IR control codes from a standard remote control IC into the IPod's uart protocol.
The receiver board is powered from +3.3 v and we simply need to make 3 connections to the board , +3.3v , Gnd and RxD. A pin out of the IPod 3G/4G remote plug is given below:-
The IR transmitter unit contains a single "Blob covered" IC which i assume is a generic RC5 remote control transmitter chip.