draft: false
Name: Pantograph
short-description: Trace and record CV — record knob movements, loop them at bipolar speed
Language: C++ (Pico SDK + ComputerCard)
Creator: Kenny Shen
Version: 1.1
Status: Released
date-created: 2026-06-29
date-updated: 2026-07-13

tags:
  - cv
  - recorder
  - looper
  - lfo
  - envelope
  - modulation

summary: |
  Pantograph lets you trace a performance on the X and Y knobs (e.g. oscillator pitch + filter
  cutoff), record it, then loop it back out the two CV outputs at variable speeds.

  Switch UP auditions live; hold DOWN to record (monitored, so you hear it as you play);
  release to MIDDLE and it loops exactly that length. The Main
  knob sets playback speed: centre = freeze, left = reverse, right = faster.

  Patch a gate into PULSE IN 1 and MIDDLE becomes a triggered envelope; unpatched it free-loops.
  PULSE OUT 1 fires a trigger at the end of a recording.
  PULSE OUT 2 runs a gate from the shape of the recording.

panel:
  inputs:
    - id: CVIn1
      name: X Mod
      description: Live CV summed onto the CV1 output
    - id: CVIn2
      name: Y Mod
      description: Live CV summed onto the CV2 output
    - id: PulseIn1
      name: Trigger
      description: >-
        When patched, Play (Middle) becomes a one-shot: each rising edge retriggers. Unpatched = loop.
    - id: PulseIn2
      name: (unused)
      description: Not used
    - id: AudioIn1
      name: (unused)
      description: Not used
    - id: AudioIn2
      name: (unused)
      description: Not used
  outputs:
    - id: CVOut1
      name: Trace X CV
      description: Trace X playback
    - id: CVOut2
      name: Trace Y CV
      description: Trace Y playback
    - id: PulseOut1
      name: End of cycle
      description: Trigger on every trace wraparound
    - id: PulseOut2
      name: Contour Gate
      description: Gates high on trace X's recorded shape
    - id: AudioOut1
      name: (unused)
      description: Not used
    - id: AudioOut2
      name: (unused)
      description: Not used

controls:
  switch:
    up:
      name: Live
      description: Audition — X/Y play live to the CV outs, CV-in summed on top
    middle:
      name: Play
      description: Loop the recorded trace at Main-knob speed; X/Y knobs used to attenuate
    down:
      name: Record
      description: Hold to record a fresh trace; release to Middle to loop it
  knobs:
    - when: { z: any }
      main:
        name: Speed
        description: Playback speed, bipolar — centre = freeze, left = reverse, right = faster
      x:
        name: Trace X
        description: Performance value in Live/Record; playback depth (attenuation) in Play
      y:
        name: Trace Y
        description: Performance value in Live/Record; playback depth (attenuation) in Play

leds: |
  Live: two 3-LED level bars (brightness = |output| per X/Y).
  Record: buffer-fill gauge (LEDs fill 1->6 as recording approaches the ~75s cap).
  Play: a moving position dot — reverses and freezes with speed,
  and holds on the last LED when a trigger finishes.