The worlds of electronic music and video games often collide - most commonly through chip music and FM synthesis engines. Here we have an interesting fusion using retro controllers to send MIDI. Youtuber Po8laster has created two versions for the Gamecube and N64 pads to send messages to synths, DAWs and drum machines..
He's recently added to the above video with some long form explanations for the Gamecube and N64 controllers respectively. These are open source devices with all code and schematics available on his GitHub page: https://github.com/po8aster. You can buy finished units off him if that's not your thing,.
More information here: https://www.petercatproductions.com/