Node Web Bluetooth

Node.js implementation of the Web Bluetooth Specification

Prerequisites

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

Installation

$ npm install webbluetooth

Getting Started

See the examples or view the API documentation at:

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

Supported Platforms

Binaries are built to support the following platforms:

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();
...

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();
...

Specification

The Web Bluetooth specification can be found here:

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

Implementation Status

Functions

• getAdapters() - list available bluetooth adapters

new Bluetooth options

• deviceFound - A device found callback function to allow the user to select a device
• scanTime - The amount of seconds to scan for the device (default is 10)
• allowAllDevices - Optional flag to automatically allow all devices
• referringDevice - An optional referring device
• adapterIndex - An optional index of bluetooth adapter to use (default is 0)

bluetooth

• getAvailability()
• 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

Building

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

yarn build:all

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