Name: Hot Fuzz
short-description: A stereo fuzz/distortion + resonant wah effects processor with manual and auto-wah modes, built on fixed-point DSP.
Language: C++ (Pico SDK + ComputerCard)
Creator: Joep Vermaat
contact:
  email: joep@joep-i.nl
  website: https://codeberg.org/johantv/
Version: 1.0
Status: Released
License: MIT
date-created: 2026-07-04
date-updated: 2026-07-04
Repository: https://codeberg.org/johantv/hot-fuzz

tags:
  - fuzz
  - distortion
  - wah
  - filter
  - effect
  - envelope-follower

summary: |
  Hot Fuzz is a stereo fuzz/wah effects card. It combines a clipper (soft/hard/asymmetric/foldback)
  with a resonant state-variable filter for the wah sweep, and supports both manual
  and auto-wah modes.

  Switch Up:   Fuzz + wah. Main pot selects fuzz type (4 zones: soft/hard/asym/fold,
               CCW to CW). X pot = fuzz drive.
  Switch Mid:  Fuzz + wah blend. Main pot = dry/wet blend (CCW=dry, CW=full fuzz).
               X pot = drive.
  Switch Down: Wah mode. Main pot = manual wah sweep (auto-wah off) or
               base frequency (auto-wah on). Toggle auto-wah by double-tapping
               Down (Mid→Down→Mid→Down within 0.5 s) or by sending a rising
               edge to Pulse2. LED 4 flashes to confirm.
               X pot = dry/wet blend.

  Y pot:       Wah Q / resonance (0 = flat, 4095 = high resonance). Same in all modes.

  Pulse1:      Rising edge toggles fuzz on/off (latched). Acts in Up/Mid modes
               only. When bypassed the wah still runs on the clean signal;
               LED 0 goes dark and flashes on toggle.
  Pulse2:      Rising edge toggles auto-wah on/off (latched, any mode). Same
               effect as the double-tap Down gesture, but patchable from a
               gate or footswitch.

  CV1 (optional): overrides wah cutoff when no pot controls it (Up/Mid modes).
  CV2 (optional): adds to the X pot drive value.

  Settings are not persisted — fuzz type, auto-wah state, and all settings
  reset to defaults on power cycle.

panel:
  inputs:
    - id: AudioIn1
      name: Left Audio In
      description: Left channel input (-2048..2047, 12-bit signed)
    - id: AudioIn2
      name: Right Audio In
      description: Right channel input (-2048..2047, 12-bit signed)
    - id: CVIn1
      name: Wah CV (optional)
      description: Overrides wah cutoff in Up/Mid modes when connected
    - id: CVIn2
      name: Drive CV (optional)
      description: Adds to X pot drive value
    - id: PulseIn1
      name: Fuzz Toggle
      description: Rising edge toggles fuzz on/off (latched, Up/Mid modes only)
    - id: PulseIn2
      name: Auto-Wah Toggle
      description: Rising edge toggles auto-wah on/off (latched, any mode)
  outputs:
    - id: AudioOut1
      name: Left Audio Out
      description: Processed left channel (-2048..2047, 12-bit signed)
    - id: AudioOut2
      name: Right Audio Out
      description: Processed right channel (-2048..2047, 12-bit signed)

controls:
  knobs:
    - when: { z: up }
      main:
        name: Fuzz Type
        description: 4 zones — soft(0-1023)/hard(1024-2047)/asym(2048-3071)/fold(3072-4095)
      x:
        name: Fuzz Drive
        description: 0 = clean, 4095 = maximum fuzz
      y:
        name: Wah Q / Resonance
        description: 0 = flat filter, 4095 = high resonance
    - when: { z: middle }
      main:
        name: Fuzz Blend
        description: 0 = dry (bypass fuzz), 4095 = full fuzz wet
      x:
        name: Fuzz Drive
        description: 0 = clean, 4095 = maximum fuzz
      y:
        name: Wah Q / Resonance
        description: 0 = flat filter, 4095 = high resonance
    - when: { z: down }
      main:
        name: Wah Frequency / Auto-Wah Base
        description: Manual sweep (auto-wah off) or base frequency (auto-wah on). Toggle auto-wah by double-tapping Down.
      x:
        name: Dry / Wet Blend
        description: 0 = dry (unprocessed), 4095 = fully wet (wah only)
      y:
        name: Wah Q / Resonance
        description: 0 = flat filter, 4095 = high resonance
  leds:
    - display: list
      items:
        - id: LED0
          name: Fuzz Drive
          description: Brightness follows drive pot (Up/Mid). Off in Down mode. Dark while fuzz is bypassed via Pulse1; brief flash on toggle.
        - id: LED1
          name: Fuzz / Wah Blend
          description: Brightness follows blend amount (Mid = fuzz blend, Down = wah blend). Off in Up mode.
        - id: LED2
          name: Wah Sweep
          description: Brightness follows wah cutoff frequency position.
        - id: LED3
          name: Wah Resonance
          description: Brightness follows resonance (Y pot, 0=flat, 4095=high Q).
        - id: LED4
          name: Envelope Level
          description: Only active in Down mode auto-wah; off in all other modes. Brightness follows envelope (playing dynamics).
        - id: LED5
          name: Fuzz Type
          description: >
            Pattern indicates current fuzz type (set in Up mode):
            soft=steady dim, hard=steady bright, asym=slow blink, fold=fast blink.
            Always visible regardless of switch position.