Node Web Bluetooth

Node.js implementation of the Web Bluetooth Specification

Prerequisites

Node.js > v10.20.0, which includes npm.

Installation

$ npm install webbluetooth
Copy

Getting Started

See the examples or view the API documentation at:

https://thegecko.github.io/webbluetooth/

Usage

The module exports a default navigator.bluetooth instance, the Bluetooth class to allow you to instantiate your own bluetooth instances and the Bluetooth helper methods:

• bluetooth
• Bluetooth()
• BluetoothUUID.getService()
• BluetoothUUID.getCharacteristic()
• BluetoothUUID.getDescriptor()
• BluetoothUUID.canonicalUUID()

Using the default bluetooth instance

To use existing Web Bluetooth scripts, you can simply use the default bluetooth instance in place of the navigator.bluetooth object:

const bluetooth = require('webbluetooth').bluetooth;

const device = await bluetooth.requestDevice({
    filters:[{ services:[ 'heart_rate' ] }]
});

const server = await device.gatt.connect();
...
Copy

The first device matching the filters will be returned.

Creating your own bluetooth instances

You may want to create your own instance of the Bluetooth class. For example, to inject a device chooser function or control the referring device:

const Bluetooth = require('webbluetooth').Bluetooth;

const deviceFound = (device, selectFn) => {
    // If device can be automatically selected, do so by returning true
    if (device.name === 'myName') return true;

    // Otherwise store the selectFn somewhere and execute it later to select this device
};

const bluetooth = new Bluetooth({ deviceFound });

const device = await bluetooth.requestDevice({
    filters:[{ services:[ 'heart_rate' ] }]
});

const server = await device.gatt.connect();
...
Copy

Specification

The Web Bluetooth specification can be found here:

https://webbluetoothcg.github.io/web-bluetooth/

Implementation Status

bluetooth

• getAvailability() - unsupported in adapter
• referringDevice
• requestDevice()
• getDevices()
• RequestDeviceOptions.filter.name
• RequestDeviceOptions.filter.namePrefix
• RequestDeviceOptions.filter.services
• RequestDeviceOptions.filter.manufacturerData
• RequestDeviceOptions.filter.serviceData
• RequestDeviceOptions.acceptAllDevices
• RequestDeviceOptions.optionalServices
• RequestDeviceOptions.exclusionFilters
• RequestDeviceOptions.optionalManufacturerData - used in advertisements, unsupported in adapter

BluetoothDevice

• id
• name
• gatt
• forget()
• watchAdvertisements() - unsupported in adapter
• watchingAdvertisements - unsupported in adapter

BluetoothRemoteGATTServer

• device
• connected
• connect()
• disconnect()
• getPrimaryService()
• getPrimaryServices()

BluetoothRemoteGATTService

• uuid
• device
• isPrimary
• getCharacteristic()
• getCharacteristics()
• getIncludedService() - unsupported in adapter
• getIncludedServices() - unsupported in adapter

BluetoothRemoteGATTCharacteristic

• uuid
• service
• value
• properties.broadcast - unsupported in adapter
• properties.read
• properties.writeWithoutResponse
• properties.write
• properties.notify
• properties.indicate
• properties.authenticatedSignedWrites - unsupported in adapter
• properties.reliableWrite - unsupported in adapter
• properties.writableAuxiliaries - unsupported in adapter
• getDescriptor()
• getDescriptors()
• readValue()
• writeValue()
• writeValueWithResponse()
• writeValueWithoutResponse()
• startNotifications()
• stopNotifications()

BluetoothRemoteGATTDescriptor

• uuid
• characteristic
• value
• readValue()
• writeValue()

BluetoothUUID

• getService()
• getCharacteristic()
• getDescriptor()
• canonicalUUID()

Events

Bluetooth

• availabilitychanged - unsupported in adapter

Bluetooth Device

• gattserverdisconnected
• advertisementreceived - unsupported in adapter

Bluetooth Service

• serviceadded
• servicechanged - unsupported in adapter
• serviceremoved - unsupported in adapter

Bluetooth Characteristic

• characteristicvaluechanged

Other

• Device selector hook
• Examples
• API Documentation

Development

Cloning

This repository uses a submodule to reference the SimpleBLE library. Clone it as follows:

git clone https://github.com/thegecko/webbluetooth
cd webbluetooth
git submodule update --init
Copy

Building

To build the SimpleBLE module, bindings and TypeScriptsource, run:

yarn build:all
Copy

Testing

The tests are set up to use a BBC micro:bit in range with the following services available:

• Device Info Service (0000180a-0000-1000-8000-00805f9b34fb)
• LED Service (e95dd91d-251d-470a-a062-fa1922dfa9a8)
• Button Service (e95d9882-251d-470a-a062-fa1922dfa9a8)

Sample code and hex file for the v2 micro:bit can be found in the firmware folder.

To run the tests:

yarn test
Copy