I have read multiple posts and have not found a solution to this problem, and I'm not much of a programmer. Here's what I've done so far:
Downloaded a fresh install of Retropie from here (https://retropie.org.uk/download/)
Plugged in USB wireless keyboard
Went into RetroPie Bluetooth setup and chose Register and Connect Bluetooth Devices. Held down Share and Playstation buttons on controller until flashing and was able to see wireless controller listed as option. Selected this. Chose DisplayYesNo as security option and received confirmation of success. Exited back to RetroPie setup screen.
- Opened Configure Input screen. One controller was detected. Tried pressing buttons on controller, but none was recognized.