I have a NAD receiver, the NAD T752, this has an IR receiver port on the back. It would be nice if I could use this port to control the receiver, e.g. change input source, increase/decrease volume etc.
I found a hardware interface which can connect to this port:
I think it should be possible to adapt the interface to be controlled by the gpio port of the Raspberry PI. Unfortunately my electronics skills have faded away since I left uni about 20 years ago.
Could anyone guide me in the right directions on how to adapt the circuit to be controlled by the GPIO? Maybe replacing the IR receiver in the schematic with an optocoupler should suffice?