WOLFPUNK Chord Machine

June 15, 2025 · View on GitHub

A CircuitPython-based MIDI chord machine built for the Adafruit MacroPad RP2040. Inspired by devices like the Pocket Audio HiChord, this custom firmware transforms the MacroPad into a powerful chord and arpeggiator performance tool with rich LED feedback and a dynamic OLED interface.

🔧 Required Libraries

Ensure your lib/ directory on the CIRCUITPY drive contains the following CircuitPython libraries:

  • adafruit_display_text
  • adafruit_macropad
  • adafruit_midi
  • adafruit_pixelbuf

You can download these from the Adafruit CircuitPython Bundle.

🚀 Setup Instructions

  1. Copy code.py to the root of your CIRCUITPY drive.
  2. Install the required libraries in a lib folder on CIRCUITPY.
  3. Reboot the MacroPad or press Ctrl+D in the serial console.

Upon boot, you'll see:

  • A boot animation with animated pixels and a "WOLFPUNK CHORDS" title.

🎹 How to Use

🔢 Keys 1–7 (Lit yellow):

  • Trigger chord notes. Each key corresponds to a scale degree in the key.

🔘 Key Functions

  • Key 8: Cycle through chord inversions (0, 1, 2)
  • Key 9: Shift octave (-1, 0, +1)
  • Key 10: Change arpeggiator mode (Off → Up → Down → Random)
  • Key 11: Toggle Latch mode (Hold chords after release)
  • Key 12: Toggle chord type (Major / Minor / Diminished)

🎛 Encoder

  • Turn: Adjust key offset
  • Press + Turn: Adjust BPM

💡 LED Feedback

  • Keys 1–7: Yellow when idle, green when pressed or arpeggiated.
  • Key 8: Red (brightness indicates inversion)
  • Key 9: Blue (brightness indicates octave)
  • Key 10: Orange (tempo pulse when arp active, dim when off)
  • Key 11: Purple (bright = latch on, dim = off)
  • Key 12: Green (brightness varies by chord type)

🖥 OLED Display

Chord: 60 64 67
Key: +1 | Oct: 0
Inv: 1 | Lt: 1 | Maj
Arp: Up | BPM: 120
  • Chord: MIDI notes of the current chord
  • Key: Offset in semitones
  • Oct: Octave shift
  • Inv: Chord inversion
  • Lt: Latch (0 = Off, 1 = On)
  • Maj: Chord type
  • Arp: Arpeggiator mode
  • BPM: Tempo

📦 License

GNU General Public License v3.0 (GPL-3.0). Created for creative MIDI exploration with the Adafruit MacroPad RP2040.

🐺 About

Developed by WOLFPUNK for expressive chord and performance interaction, ideal for live electronic music and generative composition.