draft: false
Name: drumdrum
short-description: DFAM-style 8-step sequencer
Language: C++ (Pico SDK + ComputerCard)
Creator: Moses Hoyt
Version: 1.2.0
Status: WIP
License: MIT
date-created: 2026-05-05
date-updated: 2026-05-12
Editor: https://mohoyt.com/drumdrum.html

tags:
  - sequencer
  - percussion
  - cv
  - usb-host
  - web-midi

summary: |
  drumdrum is an 8-step DFAM-inspired sequencer card.
  Switch up is play (tempo, length, VCO2 offset), switch middle is edit (step pitch and velocity),
  and switch down supports short press cursor advance / long press play-pause.
  Sequence data is randomized on reset and shared across panel, Monome Grid, 8mu, and browser editor workflows.
  Pulse In 1 is external clock and Pulse In 2 resets to step 1.

panel:
  inputs:
    - id: PulseIn1
      name: External Clock
      description: Rising edge advances one sequencer step, overriding internal clock
    - id: PulseIn2
      name: Reset
      description: Rising edge resets playback step to step 1
    - id: CVIn1
      name: Velocity Mod
      description: Summed into velocity CV output (decay modulation use-case)
    - id: CVIn2
      name: Global Transpose
      description: Global pitch transpose applied to both pitch outputs
  outputs:
    - id: CVOut1
      name: VCO 1 Pitch CV
      description: Calibrated 1V/oct pitch from current step
    - id: CVOut2
      name: Velocity CV
      description: Step velocity-derived CV with CV In 1 modulation
    - id: AudioOut1
      name: White Noise
      description: Continuous white noise output
    - id: AudioOut2
      name: VCO 2 Pitch CV
      description: Pitch CV mirror with Y offset (via audio DAC path, uncalibrated)
    - id: PulseOut1
      name: Step Trigger
      description: Trigger pulse every step (also preview trigger while paused in edit mode)
    - id: PulseOut2
      name: End-of-Cycle Trigger
      description: Trigger pulse when sequence wraps from last step to first

controls:
  switch:
    down:
      name: Play/Pause Toggle
      description: Toggles sequencer running state
    tap:
      name: Advance Edit Cursor
      description: Moves edit cursor to next step
  knobs:
    - when: { z: up }
      main:
        name: Tempo
        description: Internal tempo (ignored when external clock is patched)
      x:
        name: Sequence Length
        description: Active steps (1-8) with pickup behavior
      y:
        name: VCO 2 Offset
        description: VCO 2 pitch offset relative to VCO 1 (semitones)
    - when: { z: middle }
      main:
        name: Tempo
        description: Internal tempo while editing
      x:
        name: Step Pitch
        description: Pitch for selected edit step (with pickup)
      y:
        name: Step Velocity
        description: Velocity for selected edit step (with pickup)
  leds:
    - display: grid
      items:
        - id: LED0
          name: Step encoding
          description: Six LEDs encode current step (play mode) or edit cursor (edit mode) using binary-like 1..8 patterns

host:
  usb:
    - name: Monome Grid
      role: host-controller
      description: 16x8 grid editing and transport control when connected at boot
    - name: Music Thing 8mu
      role: host-controller
      description: MIDI fader/button control of per-step pitch and velocity workflows
    - name: Browser Editor
      role: usb-midi-device
      description: WebMIDI SysEx editor (`editor.html` or hosted Editor URL) for full pattern editing