I have a Sanyo GXT929U stereo, and I am pretty sure it uses IR. But I don't have the remote. Is there any way I could make one?
Sebi said:If this device so pretty old, maybe it uses independent (and commercial) IC in IR-receiver stage. Try open the case, and localizing the IR-receiver transistor (or diode).Follow the signal wire on PCB to deoder IC and read the type of IC. Maybe i can find the datasheet with code-system of IC. If we have success with this method, maybe can find a transmitter IC, with full command capability.
You wrote: enough the volume control. I'm not sure this way simplyer, because You must to build a voltage controllable preamplifier (i know different types of IC), and IR RX-TX pair (and a pretty case for TX...)