A Node.js BLE (Bluetooth Low Energy) central module.
Want to implement a peripheral? Check out bleno.
Note: macOS / Mac OS X, Linux, FreeBSD and Windows are currently the only supported OSes.
// Read the battery level of the first found peripheral exposing the Battery Level characteristic
const noble = require('@abandonware/noble');
noble.on('stateChange', async (state) => {
if (state === 'poweredOn') {
await noble.startScanningAsync(['180f'], false);
}
});
noble.on('discover', async (peripheral) => {
await noble.stopScanningAsync();
await peripheral.connectAsync();
const {characteristics} = await peripheral.discoverSomeServicesAndCharacteristicsAsync(['180f'], ['2a19']);
const batteryLevel = (await characteristics[0].readAsync())[0];
console.log(`${peripheral.address} (${peripheral.advertisement.localName}): ${batteryLevel}%`);
await peripheral.disconnectAsync();
process.exit(0);
});- Install Xcode
- Kernel version 3.6 or above
libbluetooth-dev- Run the following command to grant node the necessary privileges to read BLE data:
sudo setcap cap_net_raw+eip $(eval readlink -f $(which node))(Explanation)
sudo apt-get install bluetooth bluez libbluetooth-dev libudev-devMake sure node is on your PATH. If it's not, some options:
- Symlink
nodejstonode:sudo ln -s /usr/bin/nodejs /usr/bin/node - Install Node.js using the NodeSource package
sudo yum install bluez bluez-libs bluez-libs-develSee Configure Intel Edison for Bluetooth LE (Smart) Development.
Make sure you have GNU Make:
sudo pkg install gmakeDisable automatic loading of the default Bluetooth stack by putting no-ubt.conf into /usr/local/etc/devd/no-ubt.conf and restarting devd (sudo service devd restart).
Unload ng_ubt kernel module if already loaded:
sudo kldunload ng_ubtMake sure you have read and write permissions on the /dev/usb/* device that corresponds to your Bluetooth adapter.
node-gyp requirements for Windows
Install the required tools and configurations using Microsoft's windows-build-tools from an elevated PowerShell or cmd.exe (run as Administrator).
npm install --global --production windows-build-toolsnode-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 setup guide on Bluetooth LE with Node.js and Noble on Windows
npm install @abandonware/nobleconst noble = require('@abandonware/noble');All operations have two API variants – one expecting a callback, one returning a Promise (denoted by Async suffix).
Additionally, there are events corresponding to each operation (and a few global events).
For example, in case of the "discover services" operation of Peripheral:
- There's a
discoverServicesmethod expecting a callback:peripheral.discoverServices((error, services) => { // callback - handle error and services });
- There's a
discoverServicesAsyncmethod returning a Promise:try { const services = await peripheral.discoverServicesAsync(); // handle services } catch (e) { // handle error }
- There's a
servicesDiscoverevent emitted after services are discovered:peripheral.once('servicesDiscover', (services) => { // handle services });
API structure:
- Scanning and discovery
- Peripheral
- Connect
- Event: Connected
- Disconnect or cancel a pending connection
- Event: Disconnected
- Update RSSI
- Event: RSSI updated
- Discover services
- Discover all services and characteristics
- Discover some services and characteristics
- Event: Services discovered
- Read handle
- Event: Handle read
- Write handle
- Event: Handle written
- Service
- Characteristic
- Descriptor
noble.on('stateChange', callback(state));state can be one of:
unknownresettingunsupportedunauthorizedpoweredOffpoweredOn
noble.startScanning(); // any service UUID, no duplicates
noble.startScanning([], true); // any service UUID, allow duplicates
var serviceUUIDs = ['<service UUID 1>', ...]; // default: [] => all
var allowDuplicates = falseOrTrue; // default: false
noble.startScanning(serviceUUIDs, allowDuplicates[, callback(error)]); // particular UUIDsNOTE: noble.state must be poweredOn before scanning is started. noble.on('stateChange', callback(state)); can be used to listen for state change events.
noble.on('scanStart', callback);The event is emitted when:
- Scanning is started
- Another application enables scanning
- Another application changes scanning settings
noble.stopScanning();noble.on('scanStop', callback);The event is emitted when:
- Scanning is stopped
- Another application stops scanning
noble.on('discover', callback(peripheral));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: trueOrFalseOrUndefined, // true or false, or undefined if not known advertisement: { localName: '<name>', txPowerLevel: someInteger, serviceUuids: ['<service UUID>', ...], serviceSolicitationUuid: ['<service solicitation UUID>', ...], manufacturerData: someBuffer, // a Buffer serviceData: [ { uuid: '<service UUID>', data: someBuffer // a Buffer }, // ... ] }, rssi: integerValue, mtu: integerValue // MTU will be null, until device is connected and hci-socket is used };
Note: On OS X, the address will be set to 'unknown' if the device has not been connected previously.
noble.on('warning', callback(message));noble.reset()peripheral.connect([callback(error)]);Some of the bluetooth devices doesn't connect seamlessly, may be because of bluetooth device firmware or kernel. Do reset the device with noble.reset() API before connect API.
peripheral.once('connect', callback);peripheral.disconnect([callback(error)]);peripheral.once('disconnect', callback);peripheral.updateRssi([callback(error, rssi)]);peripheral.once('rssiUpdate', callback(rssi));peripheral.discoverServices(); // any service UUID
var serviceUUIDs = ['<service UUID 1>', ...];
peripheral.discoverServices(serviceUUIDs[, callback(error, services)]); // particular UUIDsperipheral.discoverAllServicesAndCharacteristics([callback(error, services, characteristics)]);var serviceUUIDs = ['<service UUID 1>', ...];
var characteristicUUIDs = ['<characteristic UUID 1>', ...];
peripheral.discoverSomeServicesAndCharacteristics(serviceUUIDs, characteristicUUIDs, [callback(error, services, characteristics));peripheral.once('servicesDiscover', callback(services));peripheral.readHandle(handle, callback(error, data));peripheral.once('handleRead<handle>', callback(data)); // data is a Buffer<handle> is the handle identifier.
peripheral.writeHandle(handle, data, withoutResponse, callback(error));peripheral.once('handleWrite<handle>', callback());<handle> is the handle identifier.
service.discoverIncludedServices(); // any service UUID
var serviceUUIDs = ['<service UUID 1>', ...];
service.discoverIncludedServices(serviceUUIDs[, callback(error, includedServiceUuids)]); // particular UUIDsservice.once('includedServicesDiscover', callback(includedServiceUuids));service.discoverCharacteristics() // any characteristic UUID
var characteristicUUIDs = ['<characteristic UUID 1>', ...];
service.discoverCharacteristics(characteristicUUIDs[, callback(error, characteristics)]); // particular UUIDsservice.once('characteristicsDiscover', callback(characteristics));characteristics{ uuid: '<uuid>', properties: ['...'] // 'broadcast', 'read', 'writeWithoutResponse', 'write', 'notify', 'indicate', 'authenticatedSignedWrites', 'extendedProperties' };
characteristic.read([callback(error, data)]);characteristic.on('data', callback(data, isNotification));
characteristic.once('read', callback(data, isNotification)); // legacyEmitted when:
- Characteristic read has completed, result of
characteristic.read(...) - Characteristic value has been updated by peripheral via notification or indication, after having been enabled with
characteristic.notify(true[, callback(error)])
Note: isNotification event parameter value MAY be undefined depending on platform. The parameter is deprecated after version 1.8.1, and not supported on macOS High Sierra and later.
characteristic.write(data, withoutResponse[, callback(error)]); // data is a Buffer, withoutResponse is true|falsewithoutResponse:false: send a write request, used with "write" characteristic propertytrue: send a write command, used with "write without response" characteristic property
characteristic.once('write', withoutResponse, callback());Emitted when characteristic write has completed, result of characteristic.write(...).
characteristic.broadcast(broadcast[, callback(error)]); // broadcast is true|falsecharacteristic.once('broadcast', callback(state));Emitted when characteristic broadcast state changes, result of characteristic.broadcast(...).
characteristic.subscribe([callback(error)]);Subscribe to a characteristic.
Triggers data events when peripheral sends a notification or indication. Use for characteristics with "notify" or "indicate" properties.
characteristic.once('notify', callback(state));Emitted when characteristic notification state changes, result of characteristic.notify(...).
characteristic.unsubscribe([callback(error)]);Unsubscribe from a characteristic.
Use for characteristics with "notify" or "indicate" properties
characteristic.discoverDescriptors([callback(error, descriptors)]);characteristic.once('descriptorsDiscover', callback(descriptors));descriptors:[ { uuid: '<uuid>' }, // ... ]
descriptor.readValue([callback(error, data)]);descriptor.once('valueRead', data); // data is a Bufferdescriptor.writeValue(data[, callback(error)]); // data is a Bufferdescriptor.once('valueWrite');By default, noble will select appropriate Bluetooth device bindings based on your platform. You can provide custom bindings using the with-bindings module.
var noble = require('noble/with-bindings')(require('./my-custom-bindings'));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 the following way:
- apt:
sudo apt-get install libcap2-bin - yum:
su -c \'yum install libcap2-bin\'
hci0 is used by default.
To override, set the NOBLE_HCI_DEVICE_ID environment variable to the interface number.
For example, to specify hci1:
sudo NOBLE_HCI_DEVICE_ID=1 node <your file>.jsBy 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 NOBLE_REPORT_ALL_HCI_EVENTS environment variable can be used to bypass it.
sudo NOBLE_REPORT_ALL_HCI_EVENTS=1 node <your file>.jsBy 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 NOBLE_MULTI_ROLE environment variable can be used to bypass this behaviour.
Note: this requires a Bluetooth 4.1 adapter.
sudo NOBLE_MULTI_ROLE=1 node <your file>.jsThis limit is imposed by the Bluetooth adapter hardware as well as its firmware.
| Platform | |
|---|---|
| OS X 10.11 (El Capitan) | 6 |
| Linux/Windows - Adapter-dependent | 5 (CSR based adapter) |
Some BLE adapters cannot connect to a peripheral while they are scanning (examples below). You will get the following messages when trying to connect:
Sena UD-100 (Cambridge Silicon Radio, Ltd Bluetooth Dongle (HCI mode)): Error: Command disallowed
Intel Dual Band Wireless-AC 7260 (Intel Corporation Wireless 7260 (rev 73)): Error: Connection Rejected due to Limited Resources (0xd)
You need to stop scanning before trying to connect in order to solve this issue.
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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.