WIP

node-lwm2m is an implementation of the Open Mobile Alliance's Lightweight M2M protocol (LWM2M).

This is a fork of @telefonicaid's lwm2m-node-lib, but adds missing features in the original project required for a compliant implementation. Considerable work has been done so that it is now a distinct project.

LWM2M is a profile for device services based on CoAP. LWM2M defines a simple object model and a number of interfaces and operations for device management.

npm install --save lwm2m

var server = require('lwm2m').createServer();

server.on('register', function(params, accept) {
  setImmediate(function() {
    server
    .read(params.ep, '3/0')
    .then(function(device) {
      console.log(JSON.stringify(device, null, 4));
    })
  });
  accept();
});

server.listen(5683);

• createServer()
• listen()
• read()
• write()
• execute()
• writeAttributes()
• discover()
• create()
• remove()
• observe()
• cancel()

• Schema()
• Schema.validate()

Server constructor.

Options:

• type: indicates if the server should create IPv4 connections (udp4) or IPv6 connections (udp6). Defaults to udp6.
• deviceRegistry: defaults to an in-memory registry.
• piggybackReplyMs: set the number of milliseconds to wait for a piggyback response. Default 50.

Events:

• register: device registration request.
• update: device registration update.
• unregister: device unregistration.

Start listening for connections, default port is 5683. This function is inherited from node-coap.

Read path on device with endpoint name ep. The callback is given the two arguments (err, res), where res is parsed using schema. A path represents either an LWM2M Object instance or resource.

Options:

• schema defining resources.

Example:

var schema = Schema({
  test: { id: 1, type: Number }
});

server.read('dev0', '/1024/11', { schema }, function(err, res) {
  assert(res.hasOwnProperty('test'));
  assert(typeof res.test == 'number');
});

Schemas can be preloaded on the constructor e.g.

var server = lwm2m.createServer({ schemas: {
  '/3': Schema(require('lwm2m/oma/device.json'))
}});

server.read('dev0', '/3/0', function(err, device) {
  assert(device.hasOwnProperty('manufacturer'));
});

server.read('dev0', '/3/0/5', function(err, pwrSrcs) {
  assert(Array.isArray(pwrSrcs));
});

Note:

If no schema is provided will return a Buffer if the payload is TLV-encoded or opaque, or an String otherwise.

Makes a Write operation over the designed resource ID of the selected device.

Makes an Execute operation over the designed resource ID of the selected device.

Write attributes into path of endpoint ep.

Example:

var attr = {
  "pmin": 5,
  "pmax": 10
};

server.writeAttributes('dev0', '3303/0/5700', attr, function(err, res) {
   assert.ifError(err);
});

Execute a discover operation for the selected resource.

Create a new LWM2M Object for path, where path is an Object ID.

Deletes the LWM2M Object instance in path of endpoint ep

Observe changes in path of device with endpoint name ep. The notification behaviour, e.g. periodic or event-triggered reporting, is configured with the writeAttributes method. The callback is given the two arguments (err, stream), where stream is a Readable Stream. To stop receiving notifications close() the stream and (optionally) call cancel() on the same ep and path and .

Example:

server.observe('dev0', '/1024/10/1', function(err, stream) {
  stream.on('data', function(value) {
    console.log('new value %s', value);
  });
  
  stream.on('end', function() {
    console.log('stopped observing');
  });
});

Cancel an observation for path of device ep.

Schema constructor.

An Schema describes the shape of an Smart Object. An Object is a collection of resources with the following properties:

• id: the Resource ID
• type: String | Number | Boolean | Buffer; [type] for multiple instances
• enum: values are enumerated (Optional)
• range: values are within a range (Optional)
• required: the resource is mandatory. Defaults to false

Examples

A temperature sensor:

var temperature = new Schema({
  sensorValue: {
    id: 5700,
    type: Number,
    required: true
  },
  units: {
    id: 5701,
    type: String
  }
});

A light controller:

var lightControl = new Schema({
  onOff: {
   id : 5850,
   type: Boolean,
   required: true
  },
  dimmer: {
    type: Number,
    id: 5851,
    range: { min: 0, max: 100 }
  },
  units: {
    id: 5701,
    type: String
  }
});

LWM2M Server Object:

var schema = new Schema({
  serverId: {
    id: 0,
    type: Number,
    range: { min: 1, max: 65535 }
  },
  lifetime: {
    id: 1,
    type: Number
  },
  notifyStoring: {
    id: 6,
    type: Boolean
  },
  binding: {
    id: 7,
    type: String,
    enum: ['U','UQ','S','SQ','US','UQS']
  }
});

See oma directory for examples of definitions.

validates obj with schema.