Stripped out JavaScript MQTT module that does basic PUB/SUB. Minifies to 1.4KB, intended for devices running Espruino, particularly the ESP8266.

• Supports QoS 0 only.
• Supports authentication on username and password.

Some considerable effort has gone into ensuring safe reconnection in event of MQTT broker disconnecting us and or loss of network, minimising leaked memory and ensuring no duplicated event listeners, and subsequent processes.

Please note. tinyMQTT library defines a single variable in the global namespace. In tests this has proven the best way to keep a compact code base. Variable is "_q".

Using the Espruino Web IDE you can either download and use as a local module or require the file directly from this Github respository. For example, this works:

var mqtt = require("https://github.com/olliephillips/tinyMQTT/blob/master/tinyMQTT.min.js"); 

var mqtt = require("tinyMQTT").create(server); mqtt.connect(); // Connects on default port of 1883 

var mqtt = require("tinyMQTT").create(server, {	username: "username",	password: "password",	port: 8883 }); mqtt.connect(); 

var mqtt = require("tinyMQTT").create("test.mosquitto.org"); mqtt.on("connected", function(){	mqtt.subscribe("espruino/test"); }); mqtt.on("message", function(msg){	console.log(msg.topic);	console.log(msg.message); }); mqtt.on("published", function(){	console.log("message sent"); }); mqtt.on("disconnected", function(){	console.log("disconnected"); }); var wifi = require("Wifi"); wifi.connect("username", {password:"mypassword"},function(){	mqtt.connect(); }); 

If you want to reconnect in event of broker disconnection or wifi outage add mqtt.connect(); to the disconnected event listener. Reconnection will be attempted indefinitely at 2 second intervals. Once reconnected publishing should restart, and subscriptions will be honoured.

mqtt.on("disconnected", function(){	console.log("disconnected");	mqtt.connect(); }); 

@gfwilliams, @tve, @HyGy, @MaBecker, @gulfaraz. Thanks for the advice, tips, testing and pull requests!