euclid-16

This is a prototype of a sequencer made in a Raspberry Pi Pico. Particulary, an euclidean sequencer, whose steps can be added/removed uniformely in the grid by rotating the encoder.

VID_20221020_162245915.mp4

For the moment, features are:

• 4 voices
• 16 steps
• Audio output through PWM (optionally I2S)
• MIDI USB note output
• Clock input 5V trigger pulse (ie. used by Korg Volca, etc)
• 16 led using 2 shift registers 74hc595, or NeoPixel display
• Event-based system to hook into seq/UI events, see src/main.py
• Save up to 16 sequences

Usage

• Rotate encoder (no buttons held) → Adjust TEMPO

• Press a button → Select voice

• Hold a button + rotate encoder:

  • Btn 1 → Add/remove HITS
  • Btn 2 → Add/remove OFFSET
  • Btn 3 → Add/remove STEPS
  • Btn 4 → Select sequence (1–16)
    • Also press encoder button while holding Btn 4 → Save sequence

• Press encoder button → PLAY/STOP sequence

• Button combos:

  • Btn 1 + Btn 2 → Clear pattern
  • Btn 2 + Btn 3 → Random pattern

TODO

• Porting to Arduino C. Despite CircuitPython is great to play around, it doesn't provide hardware timer interrupts, which is critical to keep tempo consistent. Maybe worth trying plain MicroPython, but C surely is a better idea.
• Add more voices
• Sync out
• MIDI sync in
• Improve RC filter on audio PWM pin (currently, just a 4.7k + 1uF cap)