Homie Device

This is a NodeJS port of the Homie convention for lightweight IoT device interaction on an MQTT message bus.

It is modeled after the great work done for ESP8266 devices, with the goal of not only following the Homie Convention, but at adhering to the implementation interface so both message and API interfaces are familiar.

It's great for mixing ESP8266 devices with Raspberry Pi and other linux or windows based systems on the same MQTT network.

Features

Device, Node, and Property with ESP8266-like interface
Auto MQTT connect with optional username/password
Auto MQTT re-connect
Device config matching ESP8266 config JSON
Periodic $stats/uptime publishing
$online will
Device topic events
Broadcast message events
Periodic stats interval events
Device/node/property announcement on connect
Property send with retained value
Settable properties
Property ranges
Lightweight
Full test coverage

Quick Start

First, get a local MQTT broker running and a window opened subscribing to the 'devices/#' topic.

Next, add these lines to an index.js file and run it:

var HomieDevice = require('homie-device');
var myDevice = new HomieDevice('bare-minimum');
myDevice.setup();

Congratulations, you've got a running Homie device!

Take a look at the messages on your MQTT bus under devices/bare-minimum. Then ctrl-c the program and watch the broker administer the will.

Setting Firmware

To publish the firmware name & version, call myDevice.setFirmware():

var HomieDevice = require('homie-device');
var myDevice = new HomieDevice('bare-minimum');
myDevice.setFirmware('nodejs-test', '0.0.1');
myDevice.setup();

Adding a Node

Devices aren't much use until they have some nodes and properties. Place the following into the index.js file and run it again:

var HomieDevice = require('homie-device');
var myDevice = new HomieDevice('my-device');
var myNode = myDevice.node('my-node', 'test node friendly name', 'test-node');
myNode.advertise('my-property-1').setName('Friendly Prop Name').setUnit('W').setDatatype('integer');
myDevice.setup();

Publishing a Property

Publishing properties has the same interface as the Homie ESP8266 implementation:

var HomieDevice = require('homie-device');
var myDevice = new HomieDevice('my-device');
var myNode = myDevice.node('my-node', 'test node friendly name', 'test-node');
myNode.advertise('my-property-1').setName('Friendly Prop Name').setUnit('W').setDatatype('integer');
myDevice.setup();

myNode.setProperty('my-property-1').send('property-value');

Settable Properties

To set properties from MQTT messages, add a setter function when advertising the property:

var HomieDevice = require('homie-device');
var myDevice = new HomieDevice('my-device');
var myNode = myDevice.node('my-node', 'test node friendly name', 'test-node');
myNode.advertise('my-property-1').setName('Friendly Prop Name').setUnit('W').setDatatype('string').settable(function(range, value) {
  myNode.setProperty('my-property-1').setRetained().send(value);
});
myDevice.setup();

Once running, publish a message to the devices/my-device/my-node/my-property-1/set topic.

Array Nodes

Array nodes are also supported by passing lower and upper bounds on the range when creating the node.

var HomieDevice = require('homie-device');
var myDevice = new HomieDevice('my-device');

var lowerBound = 0;
var upperBound = 10;
var myNode = myDevice.node('my-node', 'test node friendly name', 'test-node', lowerBound, upperBound);

Publishing a property to a specific node index can be done like this:

var HomieDevice = require('homie-device');
var myDevice = new HomieDevice('my-device');
var myNode = myDevice.node('my-node', 'test node friendly name', 'test-node', 0, 10);
myNode.advertise('my-property-1');
myDevice.setup();

// Publishes 'property-value' to the 'devices/my-device/my-node_2/my-property-1' topic.
myNode.setProperty('my-property-1').setRange(2).send('property-value');

Setting a property on a specific node index can be done like this:

var HomieDevice = require('homie-device');
var myDevice = new HomieDevice('my-device');
var myNode = myDevice.node('my-node', 'test node friendly name', 'test-node', 0, 10);
myNode.advertise('my-property-2').settable(function(range, value) {
  var index = range.index;
  myNode.setProperty('my-property-2').setRange(index).send(value);
});
myDevice.setup();

Now publish a message to the devices/my-device/my-node_8/my-property-2/set topic.

Device Messages

Incoming messages to the device emit message events. You can listen for all messages to the devices/my-device/# topic like this:

var HomieDevice = require('homie-device');
var myDevice = new HomieDevice('my-device');

myDevice.on('message', function(topic, value) {
  console.log('A message arrived on topic: ' + topic + ' with value: ' + value);
});

myDevice.setup();

Now publish a message to the devices/my-device/my-node/my-property-2_8/set topic.

Topic Messages

You can listen for specific incoming topics by adding a listener to the message:{topic} event for the device:

var HomieDevice = require('homie-device');
var myDevice = new HomieDevice('my-device');

myDevice.on('message:my/topic', function(value) {
  console.log('A message arrived on the my/topic topic with value: ' + value);
});

myDevice.setup();

Now publish a message to the devices/my-device/my/topic topic.

Broadcast Messages

You can listen to all devices/$broadcast/# messages by adding a listener to the broadcast event:

var HomieDevice = require('homie-device');
var myDevice = new HomieDevice('my-device');

myDevice.on('broadcast', function(topic, value) {
  console.log('A broadcast message arrived on topic: ' + topic + ' with value: ' + value);
});

myDevice.setup();

Now publish a broadcast message to the devices/$broadcast/some-topic topic. All homie devices are exposed to broadcast messages.

Device Settings

To configure your device with external settings, pass a full or partial config object to the HomieDevice constructor. If you've worked with the Homie ESP8266 implementation, this will be familiar:

var HomieDevice = require('homie-device');
var config = {
  "name": "Bare Minimum",
  "device_id": "bare-minimum",
  "mqtt": {
    "host": "localhost",
    "port": 1883,
    "base_topic": "devices/",
    "auth": false,
    "username": "user",
    "password": "pass"
  },
  "settings": {
    "percentage": 55
  }
}
var myDevice = new HomieDevice(config);
myDevice.setup();

Connection

The Homie device maintains an isConnected (true/false) state, and emits a connect and disconnect event as the device becomes connected with MQTT.

Quiet Setup

If you don't want the startup message, pass the quiet flag of true to setup myDevice.setup(true).

var HomieDevice = require('homie-device');
var myDevice = new HomieDevice('bare-minimum');
myDevice.setup(true);

Contributors

License

May be freely distributed under the MIT license.

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