draft: true
Name: AM Coupler
short-description: AM radio transmitter / coupler
Language: C++ (Pico SDK + ComputerCard)
Creator: Chris Johnson
Version: 1.0
Status: Released
date-created: 2025-05-25
date-updated: 2025-05-26

tags:
  - radio
  - transmitter
  - utility
  - sample-playback

summary: |
  AM Coupler generates a medium-wave AM carrier and modulates it with audio from `AudioIn1/2` (or an
  uploaded WAV when no audio inputs are patched). Main sets coarse carrier frequency, X + `CVIn1` fine tune,
  and Y controls modulation amount. Switch (or `PulseIn1` gate when patched) controls RF on/off.

panel:
  inputs:
    - id: AudioIn1
      name: Modulator Audio 1
      description: Summed into AM modulation signal
    - id: AudioIn2
      name: Modulator Audio 2
      description: Summed into AM modulation signal
    - id: CVIn1
      name: Fine Tune CV
      description: Modulates carrier frequency with Knob X
    - id: PulseIn1
      name: RF Gate
      description: When patched, high gate enables RF output
  outputs:
    - id: AudioOut1
      name: WAV Playback Monitor
      description: Outputs uploaded WAV playback signal
    - id: AudioOut2
      name: Modulation Signal Monitor
      description: Outputs post-level modulation signal used for transmission

controls:
  knobs:
    - main:
        name: Carrier Frequency (Coarse)
        description: Tunes RF carrier roughly across MW broadcast range
      x:
        name: Carrier Frequency (Fine)
        description: Fine tune amount summed with CVIn1
      y:
        name: Modulation Level
        description: Sets modulation depth / broadcast volume
    - when: { z: middle }
      main:
        name: RF Off
        description: Carrier disabled
    - when: { z: up }
      main:
        name: RF On
        description: Carrier enabled (unless gated low by PulseIn1)
    - when: { z: down }
      main:
        name: RF On
        description: Carrier enabled (unless gated low by PulseIn1)
  leds:
    - display: list
      items:
        - id: LED0
          name: RF Enable
          description: Lit when RF carrier output is active
        - id: LED1
          name: VU Low
          description: Low-range modulation level meter
        - id: LED3
          name: VU Mid
          description: Mid-range modulation level meter
        - id: LED5
          name: VU High
          description: High-range modulation level meter