I’ve registered my N64 USB controller to RetroArch using the standard method. One thing it did not map was the proprietary buttons such as the Z trigger and C directional buttons. Mupen64Plus handles this automatically but I haven’t figured out how to do this for RetroArch roms. Has anyone else been able to figure this out? I’m pretty familiar with the retropie project at this point but I can’t find anything out about this. Running retropie 2.6 on RPi2. Thanks.
What you need to do is access the F1 menu in the emulator, go to settings then input settings -joypad mapping. Select User 1 Bind All and go through the button assigning. It wont actually ask for n64 buttons but I can tell you that the C buttons are mapped to the right analog stick; so when it asks for Right Analog Y- (Up) you would press the C-Up key on your gamepad.