This repository contains 3D-printable models, PCB design files and Arduino code needed to make an arcade controller that looks like this:
There are two versions of the Flatbox. They both use Kailh low profile (choc v1) mechanical keyboard switches. With rev1 you solder an Arduino Pro Micro and the switches onto the board. With rev2, there's no additional Arduino board, the microcontroller and the USB port are built into the main board (SMT assembly is required). See the README for each version for details on how to make them.
The included firmware is compatible with the PS3 and PC, though you can use other firmware if you want.