draft: false
Name: Quattro Formaggio
short-description: Four-voice USB MIDI poly synth to CV, gate, and audio — with SETUP learn and a browser editor
summary: |
  **Quattro Formaggio** maps USB MIDI to calibrated CV/Gate plus audio (121-patch voice matrix + ADSR),
  with host SETUP/MIDI-learn for CC/knob maps (voice, envelope, cutoff, PWM), stroke LED feedback,
  and a web editor in device mode.
Language: C++ (Pico SDK + ComputerCard)
Creator: Dan Galbraith
Version: "0.10.0"
License: MIT
Status: Beta
Editor: web
date-created: 2026-08-08
date-updated: 2026-10-13

# Vendors, unmodified and under their own MIT terms:
#   usb_midi_host.c/.h + usb_midi_host_app_driver.c
#     (c) 2023 rppicomidi, https://github.com/rppicomidi/usb_midi_host
#   ComputerCard.h
#     (c) Chris Johnson

uf2:
  - path: UF2/92_quattro_formaggio.uf2
    name: Quattro Formaggio 0.10.0

tags:
  - midi-host
  - midi-to-cv
  - synthesizer
  - polyphonic
  - web-midi
  - utility

panel:
  inputs:
    - id: AudioIn1
      name: Not used
      description: No audio input processing in current firmware
    - id: AudioIn2
      name: Not used
      description: No audio input processing in current firmware
    - id: CVIn1
      name: Not used
      description: CV inputs are not mapped in current firmware
    - id: CVIn2
      name: Not used
      description: CV inputs are not mapped in current firmware
    - id: PulseIn1
      name: Not used
      description: Pulse inputs are not mapped in current firmware
    - id: PulseIn2
      name: Not used
      description: Pulse inputs are not mapped in current firmware
  outputs:
    - id: AudioOut1
      name: Audio mix L
      description: 4-voice poly (engines 0–12); Junoish can be stereo via per-voice chorus; full-level audio (external mixer)
    - id: AudioOut2
      name: Audio mix R
      description: Right mix (stereo for Junoish chorus; otherwise matches L)
    - id: CVOut1
      name: Pitch Voice A
      description: v/Oct for voice A (default MIDI ch 1), last-note priority; C4 = 0 V
    - id: CVOut2
      name: Pitch Voice B
      description: v/Oct for voice B (default MIDI ch 2), C4 = 0 V, with pitch bend
    - id: PulseOut1
      name: Gate Voice A
      description: Gate for voice A
    - id: PulseOut2
      name: Gate Voice B
      description: Gate for voice B, last-note priority

controls:
  switch:
    up:
      name: Save SETUP exit
      description: In SETUP, move Z Up then Middle to save maps to flash and return to PLAY
    middle:
      name: Save SETUP (from Up)
      description: In SETUP, reached after Z Up — completes save to flash and returns to PLAY
    down:
      name: SETUP toggle / factory reset
      description: Hold ~1 s to toggle SETUP while running (host or device+relay); hold ~0.1 s at power-on for factory reset
  knobs:
    - main:
        name: SETUP slot select
        description: In SETUP, selects learn slot 0–12; no function in PLAY
      x:
        name: Attack (factory)
        description: Factory-mapped to Attack; re-learnable in SETUP to any slot
      y:
        name: Release (factory)
        description: Factory-mapped to Release; re-learnable in SETUP to any slot
  leds:
    - items:
        - id: LED0
          name: Status / SETUP bit0 / glyph
          description: Host mount or device blink in PLAY; SETUP slot LSB; stroke glyphs on change
        - id: LED1
          name: Activity / SETUP bit1 / glyph
          description: MIDI activity in PLAY; SETUP slot bit1; stroke glyphs
        - id: LED2
          name: Gate 1 / SETUP bit2 / glyph
          description: Pulse Out 1 in PLAY; SETUP slot bit2; stroke glyphs
        - id: LED3
          name: Gate 2 / SETUP bit3 / glyph
          description: Pulse Out 2 in PLAY; SETUP slot bit3; stroke glyphs
        - id: LED4
          name: SETUP blink A / web / glyph
          description: Alternates with LED5 in SETUP; web-linked in PLAY device mode; stroke glyphs
        - id: LED5
          name: SETUP blink B / saved / glyph
          description: Alternates with LED4 in SETUP; brief flash after flash save in PLAY; stroke glyphs

host:
  usb:
    - name: Quattro Formaggio editor
      role: editor
      description: Browser app in `web/` for reading and writing card config over Web MIDI (Chrome, USB-C data cable, close other MIDI apps)
    - name: USB MIDI Device/Host
      role: midi
      description: Dual role — host for controllers with SETUP learn (Rev ≥ 1.1), device for the editor

readme: |

  Plug a class-compliant USB MIDI keyboard into the Computer (Rev 1.1+) for dual-voice
  CV/gate plus 4-voice poly audio (121-patch voice matrix). CC 24 selects engine patch.
  Hold Z Down ~1 s to toggle SETUP and learn any CC, key, or X/Y knob to a parameter slot. Plug into a laptop
  to use web/index.html for the same maps over SysEx. Full operator docs: docs/getting-started.md