Bangle.js - Hackable Javascript Smart Watch

Bangle.js is an open-source, hackable smartwatch that you can program using JavaScript or a graphical editor (Blockly) directly from a web browser — no app store or server dependency required. It runs the Espruino JavaScript interpreter and comes with Bluetooth Low Energy, GPS, heart rate monitor, accelerometer, and AI capability via TensorFlow Lite for Microcontrollers.

Waterproof and fully self-sufficient, Bangle.js lets you install apps from the web or develop your own. All wireless programming is done via Web Bluetooth (Chrome, Edge, or Opera).

Key Features

• JavaScript Programmable – Code in JS or Blockly, wirelessly via Web Bluetooth
• Espruino Pre-Installed – Open-source JavaScript interpreter with ES5 and many ES6 features
• Bluetooth 4.2 – Advertising, Central, and Peripheral modes with Nordic UART service
• GPS – Built-in positioning
• Heart Rate Monitor – Optical PPG sensor
• Accelerometer – Motion and gesture detection
• TensorFlow Lite AI – On-device machine learning inference
• Waterproof – Suitable for everyday wear
• Open Source – No server dependency, fully self-sufficient

Software Features

• 40 KB RAM – For program memory and variables
• Graphics Library – Vector fonts, bitmap rotate and scale
• Wear-Levelled Flash Filesystem – Reliable storage with Heatshrink compression
• Wireless Debugging – Built-in debug over Bluetooth
• VT100 Terminal – Terminal support on LCD
• C / ARM Assembler – Upload native functions for performance-critical code
• Web Bluetooth IDE – Program from any compatible browser, or use Node.js CLI tools