This is a collection of easy to build adapters for connecting SNES, NES, Mega Drive/Genesis (3/6-button), Master System, Atari, Commodore, Amiga (incl. CD32) controllers to USB. Support for more controllers is on the way (Sega Saturn, NeoGeo etc.).
The Mega Drive gamepad interface is based on this repository : https://github.com/jonthysell/SegaController but almost entirely rewritten and a lot of optimisations have been made.