Arcade Trackball Controller

Created: 2023-02-07

I bought a large trackball from Sparkfun years ago, but never gave it a permanent home, until now. The triangular buttons are connected to the trackball module itself, which operates as a PS/2 mouse. I cut off the PS/2 connector and wired the trackball directly to an ATMega 32U4 dev board. That board converts it to USB, drives the LED animation, and reads the extra two buttons at the top. Those top buttons trigger "1", "5", and "ESC" as a USB keyboard for controlling MAME. Pushing both at once triggers "ESC". The button LEDs just cycle the pattern shown in the GIF above. The trackball turns red when a button is pressed.

The case is 3D printed, though if you had a sufficiently large project box, or a CNC cutter, you could save a lot of time. These are among the largest single prints I've ever done, though the cyberdeck has a larger total volume. The top took a few hours, the bottom took 14 hours. There are posts with M5 threaded inserts in the bottom that the lid screws into. The USB cable comes out of a hole in the back with a rubber grommet.