Here’s a quick rundown to get the neGcon controller working with Pcsx-Rearmed/RetroPie.
You’ll need the latest version of the PSX emulator for neGcon support. Update the lr-pcsx-rearmed emulator with the RetroPie Setup menu. Select build from source and wait a couple of minutes till it’s ready.
Connect the neGcon with a PSX-to-USB Controller Adapter to your Raspberry Pi. If all goes well you will be able to configure the neGcon buttons with emulationstation. Select ‘Configure Input’, assign some buttons (we need to edit the file later) and select OK. Now track down the config file that emulationstation has written for the USB adapter, it should be in /opt/retropie/configs/all/retroarch-joypads/. Edit the file and replace the button layout with this configuration:
Now for the last step you need to tell the emulator that a neGcon is connected, since it’s not automatically detected. Start a Playstation game and open the RGUI menu, browse to Quick Menu -> Core Options -> Pad 1 Type and select negcon.