Hi, I’m enric0r.
I’m a maker and electronics tinkerer interested in DIY music hardware and sound synthesis. ChoCo is my compact USB MIDI controller for playing and changing chords directly from a physical interface. It was inspired in part by hands-on chord instruments such as HiChord by Pocket Audio.
The project
ChoCo combines a Raspberry Pi Pico, a 3×4 keypad, an analog joystick and a 128×64 OLED. The keypad selects a scale degree, the joystick changes the chord, and the display keeps the current state visible. The firmware sends MIDI notes to a connected computer or instrument.
The ChoCo repository contains the firmware, KiCad design, tests and project notes. The documentation explains the controls, pin map, firmware setup and troubleshooting. If you build a board, check its revision against the KiCad files and firmware pin settings.
Links
The firmware and hardware files are distributed under the PolyForm Noncommercial License 1.0.0.
