draft: false
Name: Dot Dash
short-description: Type on a USB keyboard, and the card sends it as Morse code
Language: C++ (Pico SDK + ComputerCard)
Creator: Joep Vermaat
Version: "1.3"
Status: Beta
License: MIT
date-created: 2026-10-08
date-updated: 2026-10-08

contact:
  email: joep@joep-i.nl

demo-link: https://www.youtube.com/watch?v=37OTUfdDDbk

tags:
  - usb-host
  - utility
  - cv
  - audio

summary: |
  Dot Dash turns a USB keyboard into a Morse code transmitter.
  Plug a keyboard into the Workshop Computer, type letters, and each character
  is sent as dots and dashes: a square beep on **Audio Out 1**, a triangle
  melody voice on **Audio Out 2**, a gate on **Pulse Out 1**, a per-symbol
  trigger on **Pulse Out 2**, and a pitch on **CV Out 1**. Every letter and
  digit has its own note, rising with the alphabet (A is the lowest), so a
  typed word becomes a melody. All outputs play together on their separate
  jacks. Knob X sets the speed (5-40 words per minute), Knob Y the beep pitch,
  and Knob Main the master audio volume. **CV In 1** transposes the notes
  (1 V/oct, +/-2 octaves), **CV In 2** modulates the speed, **Pulse In 1** is an
  external clock (one edge per Morse unit, overriding Knob X while running), and
  **Pulse In 2** clears anything typed but not yet sent.
  When no keyboard is connected the card loops **SOS** on the audio, CV and gate
  outputs and flashes all six LEDs in that rhythm.

panel:
  inputs:
    - id: CVIn1
      name: Transpose
      description: 1 V/oct transpose for the dot/dash notes, clamped to +/-2 octaves
    - id: CVIn2
      name: Speed Mod
      description: Adds up to +/-20 WPM on top of Knob X; final speed clamped to 5-60 WPM
    - id: PulseIn1
      name: External Clock
      description: One rising edge per Morse unit (dot = 1, dash = 3, gaps 1/3/4). Overrides Knob X while the clock is running; reverts to the knob after ~2 s without an edge
    - id: PulseIn2
      name: Clear
      description: A rising edge discards the typed queue and returns to idle
  outputs:
    - id: AudioOut1
      name: Morse Beep
      description: Square-wave beep for each dot and dash, level set by Knob Main
    - id: AudioOut2
      name: Melody Voice
      description: Triangle wave at the character's pitch (follows the same note as CV Out 1), level set by Knob Main
    - id: CVOut1
      name: Character Pitch
      description: One note per character, rising with the alphabet (A is lowest); dot and dash share it. Holds through letter gaps and drops to 0 V at word gaps or when idle. Calibrated when available, tracks the Transpose input
    - id: CVOut2
      name: Speed CV
      description: The current speed as a voltage, 0 V at 5 WPM to +5 V at 60 WPM; derived from the external clock when one is driving the card
    - id: PulseOut1
      name: Key Gate
      description: High for exactly the length of each dot or dash, low during the gaps
    - id: PulseOut2
      name: Symbol Trigger
      description: A short ~2 ms trigger fired at the start of each dot or dash

controls:
  switch:
    middle:
      name: Unused
      description: The switch does not change behaviour - all outputs play together on their separate jacks
  knobs:
    - main:
        name: Volume
        description: Master level for the beep and melody audio outputs (fully down is silent; the CV outputs are unaffected)
      x:
        name: Speed
        description: Transmission speed, 5-40 words per minute (before CV In 2 modulation)
      y:
        name: Pitch
        description: Beep tone frequency, 300-2000 Hz

  leds:
    - display: list
      items:
        - id: LED0
          name: Dot
          description: Lit while a dot is being sent
        - id: LED1
          name: Dash
          description: Lit while a dash is being sent
        - id: LED2
          name: Transmitting
          description: Lit while any symbol is being sent
        - id: LED3
          name: Queue Full
          description: Flashes when you type faster than the queue can hold
        - id: LED4
          name: Clocked
          description: Lit while an external clock on Pulse In 1 is driving the card
        - id: LED5
          name: Keyboard
          description: Lit while a USB keyboard is connected

host:
  usb:
    - name: USB Keyboard
      role: host-controller
      description: Any standard USB HID keyboard; type letters, digits, space and punctuation to transmit Morse