Tiller.js

A JavaScript library for the Tiller device — gestures and LED control for the web.

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Requirements

A browser with WebHID support ChromeEdge and a Tiller device.

Installation

No build step required. Import directly as an ES module:

import { Tiller } from './src/index.js';

Quick Start

const tiller = new Tiller();

tiller
  .on('connect', () => console.log('ready'))
  .on('tap', () => tiller.toggleLed())
  .on('scroll', (delta) => window.scrollBy(0, delta));

// Auto-connects if device was previously paired — no user gesture needed
tiller.autoConnect();

// Keep a button as fallback for first-time pairing
document.getElementById('connect-btn').onclick = () => tiller.connect();

Connection

There are two ways to connect:

Method User gesture? Description
autoConnect() No Silently connects if the device has been paired before. Also listens for the device to be plugged in after page load. Emits connect when ready.
connect() Yes Uses a previously paired device if available; otherwise shows the browser device picker. Emits connect when ready.

The connect event fires in all three cases: autoConnect() finds a paired device on page load, a paired device is plugged in after page load, or connect() completes. Register on('connect', ...) once and it handles all three.

First-time pairing always requires a user gesture — the browser will not show a device picker without one. Call connect() from a button click handler the first time, then autoConnect() handles every subsequent visit automatically.

Demos

Stopwatch
Tap to start/stop, double tap to lap, long press to reset. LED reflects running state.
🎨
Color Mixer
Scroll to sweep through hues. LED matches live. Tap to save colors to a palette.
Reaction Game
Double tap to start. React to the LED color as fast as possible. Track your best times.

Constructor Options

const tiller = new Tiller({
  scrollSensitivity: 1,    // multiplier applied to scroll delta (default: 1)
  doubleTapThreshold: 300, // ms between taps to count as double tap (default: 300)
  longPressThreshold: 500, // ms held down to trigger long press (default: 500)
});

Events

All events are registered with .on(event, handler), which returns the instance for chaining.

Event Handler Description
tap () => void Device tapped once
doubletap () => void Device tapped twice in quick succession
longpress () => void Device held down past the long press threshold
press () => void Device pressed down (raw)
release () => void Device released (raw)
scroll (delta: number) => void Device rotated — delta is positive or negative
connect () => void Device connected or reconnected
disconnect () => void Device disconnected
Tap vs double tap: A double tap suppresses the two individual tap events — only doubletap fires.

Long press vs tap: Releasing after a long press only fires releasetap is suppressed.

LED Control

// Set color (r, g, b — each 0–255) and immediately turn the LED on
await tiller.setLedColor(255, 0, 0); // red
await tiller.setLedColor(0, 255, 0); // green
await tiller.setLedColor(0, 0, 255); // blue

// Turn on with the last set color
await tiller.setLedOn();

// Turn off
await tiller.setLedOff();

// Toggle
await tiller.toggleLed();

Getters

tiller.isConnected // boolean — whether a device is currently connected
tiller.ledOn       // boolean — current LED state
tiller.ledColor    // { r, g, b } — last set color

Full Example

import { Tiller } from './src/index.js';

const tiller = new Tiller({ scrollSensitivity: 10 });

tiller
  .on('connect', () => {
    document.getElementById('connect-screen').style.display = 'none';
    document.getElementById('app-screen').style.display = 'block';
  })
  .on('disconnect', () => console.log('Tiller disconnected'))
  .on('tap', () => tiller.toggleLed())
  .on('doubletap', () => tiller.setLedColor(255, 0, 0))
  .on('longpress', () => tiller.setLedColor(0, 0, 255))
  .on('scroll', (delta) => window.scrollBy(0, delta));

// Auto-connects on page load if previously paired
tiller.autoConnect();

// Fallback button for first-time pairing
document.getElementById('connect-btn').onclick = () => tiller.connect();