---
title: Morse Code
emoji: 📡
colorFrom: blue
colorTo: purple
sdk: static
pinned: false
hf_oauth: true
hf_oauth_expiration_minutes: 480
# No hf_oauth_scopes → defaults to "openid profile" (just sign-in + identity).
# This app never touches HF repos/datasets, so it must NOT request the
# read/write/manage-repos scopes (that's what triggered the scary
# "Manage all your repos" consent prompt). Sign-in identity is all the host
# shell needs to connect you to your robot via the signaling server.
short_description: Talk to Reachy Mini in Morse — taps, beeps, mic decode.
tags:
- reachy_mini
- reachy_mini_js_app
---

# Morse Code

Make your Reachy Mini speak and understand **Morse code**. The robot transmits
by *clapping its antennas together* — each hit is an audible click. Your phone
or laptop can transmit too, with beeps. Either device (or a **second Reachy
Mini** sitting across the table) listens through its microphone, detects the
hits, and decodes them back to text in real time.

Open the Space URL, sign in with Hugging Face, pick your robot. No install.

## Three tabs

- **Compose** — type a message, see its Morse, and pick who sends it: the
  robot's antennas or this device's speaker. Watch it transmit.
- **Listen** — turn on the mic and decode incoming clicks/beeps live, with a
  scope that drops a marker on every detected hit.
- **Learn** — the letter ↔ rhythm chart. Tap any tile to *feel* the rhythm
  (a letter is just a pattern of short and long beats).

## How it works (the impulse wire code)

An antenna hit is **impulsive** — one short click. You can't hold a click long
the way you hold a tone, so classic "short tone = dot, long tone = dash" can't
work on the robot. Instead every channel here uses one **onset-only** code so a
tapping robot, a beeping phone, and a second robot are all mutually
intelligible through a single detector:

- **dot** = one impulse
- **dash** = a quick double-tap (two impulses)
- letters and words are separated by progressively longer gaps

It's still real Morse — the Learn chart shows the standard `·–` patterns — just
carried as a rhythm of hits instead of tone length.

Detection is a transient-onset detector (high-pass → short-term energy →
spectral flux → peak pick) ported from the Marionette audio-sync tests and
validated end-to-end against synthetic audio (`npm test`). All timing and
detection thresholds live in Settings, so the robot clap and mic sensitivity
can be calibrated on real hardware without code changes.

## Develop

```bash
npm install
npm test          # unit tests: morse codec, wire code, detector round-trip
npm run test:e2e  # playwright (optional)
```

No build step — `sdk: static`, the host shell + SDK load from jsDelivr. Local
dev: serve the folder (e.g. `python3 -m http.server`) and open with a
`?embedded=1`-capable dev token, or just push to the Space.

### SDK pin

`@pollen-robotics/reachy-mini-sdk@1.8.0-rc1-main.dbe26af`, pinned in three
places that must stay in sync: the two `modulepreload` links in `index.html`,
the two import URLs in `main.js`, and the re-export in
`lib/animation-helpers.js`.

## Credits

Built for Reachy Mini by Pollen Robotics. Antenna-collision recipe and the
transient detector adapted from the Marionette project.