noble-device

noble-device

A Node.js lib to abstract BLE (Bluetooth Low Energy) peripherals, using noble

Install

npm install noble-device

Usage

Take a look at the Tethercell and unofficial LightBlue Bean devices for examples, but this is how you make a basic device:

var NobleDevice = require('noble-device');

var YOUR_THING_SERVICE_UUID = 'xxxxxxxxxxxxxxxxxxxxxxxx';
var YOUR_THING_NOTIFY_CHAR  = 'xxxxxxxxxxxxxxxxxxxxxxxx';
var YOUR_THING_READ_CHAR    = 'xxxxxxxxxxxxxxxxxxxxxxxx';
var YOUR_THING_WRITE_CHAR   = 'xxxxxxxxxxxxxxxxxxxxxxxx';

// then create your thing with the object pattern
var YourThing = function(peripheral) {
  // call nobles super constructor
  NobleDevice.call(this, peripheral);

  // setup or do anything else your module needs here
};

// tell Noble about the service uuid(s) your peripheral advertises (optional)
YourThing.SCAN_UUIDS = [YOUR_THING_SERVICE_UUID];

// and/or specify method to check peripheral (optional)
YourThing.is = function(peripheral) {
  return (peripheral.advertisement.localName === 'My Thing\'s Name');
};

// inherit noble device
NobleDevice.Util.inherits(YourThing, NobleDevice);

// you can mixin other existing service classes here too,
// noble device provides battery and device information,
// add the ones your device provides
NobleDevice.Util.mixin(YourThing, NobleDevice.BatteryService);
NobleDevice.Util.mixin(YourThing, NobleDevice.DeviceInformationService);

// export your device
module.exports = YourThing;

Now to use YourThing you must use one of the discover functions documented below which will find your device(s) and pass instances of your object to their callback where you must call connectAndSetUp.

var YourThing = require('YourThing');

var id = '<your devices id>';
YourThing.discoverById(function(yourThingInstance) {

  // you can be notified of disconnects
  yourThingInstance.on('disconnect', function() {
    console.log('we got disconnected! :( ');
  });

  // you'll need to call connect and set up
  yourThingInstance.connectAndSetUp(function(error) {
    console.log('were connected!');
  });

});

It doesn't do much yet, let's go back and add to our Device definition (right before module.exports)

// you could send some data
YourThing.prototype.send = function(data, done) {
  this.writeDataCharacteristic(YOUR_THING_SERVICE_UUID, YOUR_THING_WRITE_CHAR, data, done);
};

// read some data
YourThing.prototype.receive = function(callback) {
  this.readDataCharacteristic(YOUR_THING_SERVICE_UUID, YOUR_THING_READ_CHAR, callback);
};

Now in our connect and setup we can:

    yourThing.send(new Buffer([0x00, 0x01]), function() {
      console.log('data sent');
    });

    yourThing.receive(function(error, data) {
      console.log('got data: ' + data);
    });

Optionally, if you need to do some device setup or close something down before disconnect, you can override those functions:

YourThing.prototype.connectAndSetup = function(callback) {
  NobleDevice.prototype.connectAndSetup.call(this, function(error) {
    // maybe notify on a characteristic ?
    this.notifyCharacteristic(YOUR_THING_SERVICE_UUID, YOUR_THING_NOTIFY_CHAR, true, this._onRead.bind(this), function(err) {
      callback(err);
    });
  }.bind(this);
};

YourThing.prototype.onDisconnect = function() {
  // clean up ...

  // call super's onDisconnect
  NobleDevice.prototype.onDisconnect.call(this);
};

Discovery API

Discover All

function onDiscover(yourThingInstance) {
  // called for all devices discovered
}

YourThing.discoverAll(onDiscover);

Stopping a Discover All

YourThing.stopDiscoverAll(onDiscover);

Discover a single device

YourThing.discover(function(yourThingInstance) {
  // called for only the first device discovered
});

Stopping a Discover

YourThing.stopDiscover(onDiscoverCallback);

Discover with Filter

YourThing.discoverWithFilter(function(device), {
  // filter callback for device,
  //   return true to stop discovering and choose device
  //   return false to continue discovery

  return true; // or false
}, function(yourThingInstance) {
  // called for only one device discovered that matches filter
});

Discover by ID

var id = " ... "; // id of device we want to discover

YourThing.discoverById(id, function(yourThingInstance) {
  // called for only one device discovered
});