Web Bluetooth and Arduino Nano 33 BLE

An example of using Web Bluetooth API with Arduino BLE library.

Sometimes I show it to my students when we are working on a project requiring Bluetooth Low Energy and a simple App. It's easier to prototype such thing with HTML + JS rather than learning other development tools in a limited amount of time.

Repository consists of:

• A simple web app that leverages the very basics of Web Bluetooth API using async/await. Nothing special because I decided to keep it simple.
• A simple Arduino peripheral code which connects to a web browser and notify with accelerometer data.

Each example can toggle the build-in LED on Arduino pin 13.

Notes:

• Web Bluetooth can't initialize connection on its own. It must be triggered by user event. In this case - pressing a HTML button.
• Tested on Google Chrome desktop and mobile with Arduino Nano 33 BLE, may work with different compatible browser/Arduino combinations.
• Please notice that Web Bluetooth won't work on IOS.
• To receive float type characteristics from Arduino BLE library, conversion to little-endian is required to correctly read the values. (event.target.value.getFloat32(0, true);)
• parseFloat(y.toFixed(2)); rounds the float to 2 decimal numbers. I tried to exactly match the values from Arduino and Javascript sides.
• Writing to characteristic requires conversion to ArrayBuffer.