I've been building a Game Boy with a Rasperry Pi inside according to these instructions: https://superpiboy.wordpress.com/. This involved putting a Pi in a Game Boy and mapping each Game Boy input to a GPIO pin using retrogame using a custom PCB board. I have my retrogame.c file configured just like the author does in the link above (toward the bottom of the page), except I added lines for Start and Select at the bottom.

I had everything up and working a while ago but let the project get away from me. I just came back to it and found that for some reason, even though they were working fine when I left them, the controls are no longer working correctly.

I have Retropie installed and use retrogame to map the controls. For some reason, the controls as I have them laid out in the retrogame.c file work correctly at the EmulationStation/Retropie menu screens (the screens for each emulator where you're scrolling through games). All the controls work correctly: up is up, A is A, etc.

However, once I load a game (any game, doesn't matter which emulator), the controls no longer work correctly. Specifically, pressing A does nothing and pressing Left registers both Left and A simultaneously.

I have checked and it's not an issue with the soldering (e.g. the solder is not seeping over the inputs of Left and A), and the Game Boy inputs are connected to the right GPIO pins. The only thing I can think is that something behind the scenes is keeping the emulators from properly using the controls I've set up through retrogame.

Unfortunately I don't know enough about this behind-the-scenes process to fix it. Can anyone help me understand why my controls would work fine in Retropie/EmulationStation but not in the actual games themselves? Is there some process by which I need to tell Retropie what the controls are? I'd really appreciate it. I'm also happy to provide any other screenshots or info that would be helpful.