pwagener/noble

A Node.js BLE (Bluetooth Low Energy) central module

noble

A Node.js BLE (Bluetooth Low Energy) central module.

Want to implement a peripheral? Checkout bleno

Note: Mac OS X, Linux and Windows are currently the only supported OSes. Other platforms may be developed later on.

Prerequisites

OS X

• install Xcode

Linux

• Kernel version 3.6 or above
• libbluetooth-dev

Ubuntu/Debian/Raspbian

sudo apt-get install bluetooth bluez libbluetooth-dev libudev-dev

Make sure node is on your path, if it's not, some options:

• symlink nodejs to node: sudo ln -s /usr/bin/nodejs /usr/bin/node
• install Node.js using the NodeSource package

Fedora / Other-RPM based

sudo yum install bluez bluez-libs bluez-libs-devel

Intel Edison

See Configure Intel Edison for Bluetooth LE (Smart) Development

Windows

• node-gyp requirements for Windows
  • Python 2.7
  • Visual Studio (Express)
• node-bluetooth-hci-socket prerequisites
  • Compatible Bluetooth 4.0 USB adapter
  • WinUSB driver setup for Bluetooth 4.0 USB adapter, using Zadig tool

See @don's set up guide on Bluetooth LE with Node.js and Noble on Windows.

Notes

Maximum simultaneous connections

This limit is imposed upon by the Bluetooth adapter hardware as well as it's firmware.

Platform
OS X 10.11 (El Capitan)	6
Linux/Windows - Adapter dependent
	5 (CSR based adapter)

Install

npm install noble

Usage

var noble = require('noble');

Actions

Start scanning

noble.startScanning(); // any service UUID, no duplicates


noble.startScanning([], true); // any service UUID, allow duplicates


var serviceUUIDs = ["<service UUID 1>", ...]; // default: [] => all
var allowDuplicates = <false|true>; // default: false

noble.startScanning(serviceUUIDs, allowDuplicates[, callback(error)]); // particular UUID's

NOTE: noble.state must be poweredOn before scanning is started. noble.on('stateChange', callback(state)); can be used register for state change events.

Stop scanning

noble.stopScanning();

Peripheral

Connect

peripheral.connect([callback(error)]);

Disconnect or cancel pending connection

peripheral.disconnect([callback(error)]);

Update RSSI

peripheral.updateRssi([callback(error, rssi)]);

Discover services

peripheral.discoverServices(); // any service UUID

var serviceUUIDs = ["<service UUID 1>", ...];
peripheral.discoverServices(serviceUUIDs[, callback(error, services)]); // particular UUID's

Discover all services and characteristics

peripheral.discoverAllServicesAndCharacteristics([callback(error, services, characteristics));

Discover some services and characteristics

var serviceUUIDs = ["<service UUID 1>", ...];
var characteristicUUIDs = ["<characteristic UUID 1>", ...];
peripheral.discoverSomeServicesAndCharacteristics(serviceUUIDs, characteristicUUIDs, [callback(error, services, characteristics));

Service

Discover included services

service.discoverIncludedServices(); // any service UUID

var serviceUUIDs = ["<service UUID 1>", ...];
service.discoverIncludedServices(serviceUUIDs[, callback(error, includedServiceUuids)]); // particular UUID's

Discover characteristics

service.discoverCharacteristics() // any characteristic UUID

var characteristicUUIDs = ["<characteristic UUID 1>", ...];
service.discoverCharacteristics(characteristicUUIDs[, callback(error, characteristics)]); // particular UUID's

Characteristic

Read

characteristic.read([callback(error, data)]);

Write

characteristic.write(data, withoutResponse[, callback(error)]); // data is a buffer, withoutResponse is true|false

• withoutResponse:
  • false: send a write request, used with "write" characteristic property
  • true: send a write command, used with "write without response" characteristic property

Broadcast

characteristic.broadcast(broadcast[, callback(error)]); // broadcast is true|false

Subscribe

characteristic.subscribe([callback(error)]);

• subscribe to a characteristic, triggers 'data' events when peripheral sends an notification or indication
• use for characteristics with notify or indicate properties

Unsubscribe

characteristic.unsubscribe([callback(error)]);

• unsubscribe to a characteristic
• use for characteristics with notify or indicate properties

Discover descriptors

characteristic.discoverDescriptors([callback(error, descriptors)]);

Read value

descriptor.readValue([callback(error, data)]);

Write value

descriptor.writeValue(data[, callback(error)]); // data is a buffer

Handle

Read

peripheral.readHandle(handle, callback(error, data));

Write

peripheral.writeHandle(handle, data, withoutResponse, callback(error));

Events

See Node.js EventEmitter docs for more info. on API's.

Adapter state change

state = <"unknown" | "resetting" | "unsupported" | "unauthorized" | "poweredOff" | "poweredOn">

noble.on('stateChange', callback(state));

Scan started:

noble.on('scanStart', callback);

The event is emitted when scanning is started or if another application enables scanning or changes scanning settings.

Scan stopped

noble.on('scanStop', callback);

The event is emitted when scanning is stopped or if another application stops scanning.

Peripheral discovered

peripheral = {
  id: "<id>",
  address: "<BT address">, // Bluetooth Address of device, or 'unknown' if not known
  addressType: "<BT address type>", // Bluetooth Address type (public, random), or 'unknown' if not known
  connectable: <connectable>, // true or false, or undefined if not known
  advertisement: {
    localName: "<name>",
    txPowerLevel: <int>,
    serviceUuids: ["<service UUID>", ...],
    manufacturerData: <Buffer>,
    serviceData: [
        {
            uuid: "<service UUID>"
            data: <Buffer>
        },
        ...
    ]
  },
  rssi: <rssi>
};

noble.on('discover', callback(peripheral));

Warnings

noble.on('warning', callback(message));

Peripheral

Connected

peripheral.once('connect', callback);

Disconnected:

peripheral.once('disconnect', callback);

RSSI update

peripheral.once('rssiUpdate', callback(rssi));

Services discovered

peripheral.once('servicesDiscover', callback(services));

Service

Included services discovered

service.once('includedServicesDiscover', callback(includedServiceUuids));

Characteristics discovered

characteristic = {
  uuid: "<uuid>",
   // properties: 'broadcast', 'read', 'writeWithoutResponse', 'write', 'notify', 'indicate', 'authenticatedSignedWrites', 'extendedProperties'
  properties: [...]
};

service.once('characteristicsDiscover', callback(characteristics));

Characteristic

Data

Emitted when characteristic read has completed, result of characteristic.read(...) or characteristic value has been updated by peripheral via notification or indication - after having been enabled with notify(true[, callback(error)]).

characteristic.on('data', callback(data, isNotification));

characteristic.once('read', callback(data, isNotification)); // legacy

Write

Emitted when characteristic write has completed, result of characteristic.write(...).

characteristic.once('write', withoutResponse, callback());

Broadcast

Emitted when characteristic broadcast state changes, result of characteristic.broadcast(...).

characteristic.once('broadcast', callback(state));

Notify

Emitted when characteristic notification state changes, result of characteristic.notify(...).

characteristic.once('notify', callback(state));

Descriptors discovered

descriptor = {
  uuid: '<uuid>'
};

characteristic.once('descriptorsDiscover', callback(descriptors));

Descriptor

Value read

descriptor.once('valueRead', data);

Value write

descriptor.once('valueWrite');

Running on Linux

Running without root/sudo

Run the following command:

sudo setcap cap_net_raw+eip $(eval readlink -f `which node`)

This grants the node binary cap_net_raw privileges, so it can start/stop BLE advertising.

Note: The above command requires setcap to be installed, it can be installed using the following:

• apt: sudo apt-get install libcap2-bin
• yum: su -c \'yum install libcap2-bin\'

Multiple Adapters

hci0 is used by default to override set the NOBLE_HCI_DEVICE_ID environment variable to the interface number.

Example, specify hci1:

sudo NOBLE_HCI_DEVICE_ID=1 node <your file>.js

Reporting all HCI events

By default noble waits for both the advertisement data and scan response data for each Bluetooth address. If your device does not use scan response the following environment variable can be used to bypass it.

sudo NOBLE_REPORT_ALL_HCI_EVENTS=1 node <your file>.js

bleno compatibility

By default noble will respond with an error whenever a GATT request message is received. If your intention is to use bleno in tandem with noble, the following environment variable can be used to bypass this functionality. Note: this requires a Bluetooth 4.1 adapter.

sudo NOBLE_MULTI_ROLE=1 node <your file>.js

Advanced usage

Override default bindings

By default, noble will select bindings to communicate with Bluetooth devices depending on your platform. If you prefer to specify what bindings noble should use:

var noble = require('noble/with-bindings')(require('./my-custom-bindings'));

Useful Links

• Bluetooth Development Portal
  • GATT Specifications
• Bluetooth: ATT and GATT

License

Copyright (C) 2015 Sandeep Mistry sandeep.mistry@gmail.com

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.