draft: false
Name: Siren
short-description: Multi-algorithm drone oscillator. Inspired by the Forge TME Vhikk X.
Language: C++ (Pico SDK + ComputerCard)
Creator: Moses Hoyt
Version: 0.2
Status: WIP
License: MIT
date-created: 2026-03-25
date-updated: 2026-03-26

tags:
  - drone
  - oscillator
  - stereo
  - fixed-point
  - processor

demo-link: https://youtu.be/DORHEYpUqWU

summary: |
  Siren is a drone source with 6 oscillator banks (SINE, CLST, DTON, ANLG, WSHP, WAVE).
  Use switch up for WARP/SPAN/MORPH and switch middle for SEED/SCAN/BASIS.
  Switch down (momentary) cycles banks with a smoothed crossfade.
  Pulse In 1 gates the drone; Pulse In 2 randomizes SEED on short trigger and cycles bank on long hold.
  Audio In 1 can be processed and mixed with the drone; Audio In 2 modulates SPAN.

panel:
  inputs:
    - id: AudioIn1
      name: Processor Input
      description: External audio processed by Siren's shaping path and summed with the drone # certainty: high (README + code)
    - id: AudioIn2
      name: Span Modulation
      description: External CV/audio modulation for oscillator spread (SPAN) # certainty: high (README + code)
    - id: CVIn1
      name: Pitch Modulation
      description: Added to BASIS/root pitch control
    - id: CVIn2
      name: Warp Modulation
      description: Modulates WARP amount
    - id: PulseIn1
      name: Gate
      description: Opens/closes the drone envelope
    - id: PulseIn2
      name: Seed / Bank Trigger
      description: Short pulse randomizes SEED, long hold cycles oscillator bank # certainty: high (README + code)
  outputs:
    - id: AudioOut1
      name: Left Drone Output
      description: Left channel of stereo Siren output (plus processed input, if patched)
    - id: AudioOut2
      name: Right Drone Output
      description: Right channel of stereo Siren output (plus processed input, if patched)
    - id: CVOut1
      name: Pitch CV Mirror
      description: Mirrors current basis pitch value
    - id: CVOut2
      name: Envelope CV
      description: Envelope level derived from Siren gate state
    - id: PulseOut1
      name: Sub-osc Clock
      description: Square clock derived from oscillator phase
    - id: PulseOut2
      name: Divide-by-2 Clock
      description: Divider pulse derived from PulseOut1 phase edges

controls:
  switch:
    tap:
      name: Bank Cycle
      description: Tap switch down to cycle to the next oscillator bank with crossfade
  knobs:
    - when: { z: up }
      main:
        name: Warp
        description: Cross-mod / distortion intensity (bank-dependent behavior)
      x:
        name: Span
        description: Oscillator spread / detuning amount (bank-dependent behavior)
      y:
        name: Morph
        description: Waveform and timbral scan parameter (bank-dependent behavior)
    - when: { z: middle }
      main:
        name: Seed
        description: Structural randomization parameter
      x:
        name: Scan
        description: Timbral scan parameter
      y:
        name: Basis
        description: Root pitch / frequency basis (also modulated by CV In 1)
  leds:
    - display: list
      items:
        - id: LED0
          name: Bank 1 (SINE)
          description: Lit/bright when SINE bank is active
        - id: LED1
          name: Bank 2 (CLST)
          description: Lit/bright when CLST bank is active
        - id: LED2
          name: Bank 3 (DTON)
          description: Lit/bright when DTON bank is active
        - id: LED3
          name: Bank 4 (ANLG)
          description: Lit/bright when ANLG bank is active
        - id: LED4
          name: Bank 5 (WSHP)
          description: Lit/bright when WSHP bank is active
        - id: LED5
          name: Bank 6 (WAVE)
          description: Lit/bright when WAVE bank is active