IT PATH FINDER: MQTT

Feb 3, 2018

Setup a Mosquitto MQTT Server - Ubuntu

adduser mosquitto (Mosquitto wants to run as user mosquitto)
apt-get update
apt-get install build-essential libwrap0-dev libssl-dev libc-ares-dev uuid-dev xsltproc (Install mosquitto dependencies)
cd /home/mosquitto
wget http://mosquitto.org/files/source/mosquitto-1.4.8.tar.gz
tar xvzf mosquitto-1.4.8.tar.gz
cd mosquitto-1.4.8
make
make install

Or Install you can install it in following way

wget http://repo.mosquitto.org/debian/mosquitto-repo.gpg.key
sudo apt-key add mosquitto-repo.gpg.key
cd /etc/apt/sources.list.d/
sudo wget http://repo.mosquitto.org/debian/mosquitto-wheezy.list
sudo apt-get update
sudo apt-get install mosquitto
sudo stop mosquitto
sudo mosquitto_passwd -c /etc/mosquitto/passwd <user_name>(Create new password file)
sudo gedit /etc/mosquitto/mosquitto.conf (Give the location of the password file to the Mosquitto broker config file)
Add following two lines to config file
password_file /etc/mosquitto/passwd
allow_anonymous false (prevent, clients without username and password connecting to the broker)
mosquitto -c /etc/mosquitto/mosquitto.conf (start broker)
mosquitto_sub -h localhost -p 1883 -t myTopic -u <user_name> -P <password> (verify authentication)
mosquitto_sub -t 'greetings/#' (View published messages live)

Node MQTT Simple example

pusher.js
var app = require('express')();
var server = require('http').createServer(app);
var io = require('socket.io')(server);
var redis = require('redis');
var mqtt = require('mqtt');
var client = mqtt.connect('mqtt://localhost');

server.listen(8080);
io.on("connection", function (socket) {
    console.log("new client connected");

    // socket connection indicates what mqtt topic to subscribe to in data.topic
    socket.on('subscribe', function (data) {
        console.log('Subscribing to '+data.topic);
        socket.join(data.topic);
        client.subscribe(data.topic);
    });
    // when socket connection publishes a message, forward that message
    // the the mqtt broker
    socket.on('publish', function (data) {
        console.log('Publishing to '+data.topic);
        client.publish(data.topic,data.payload);
    });



});

// listen to messages coming from the mqtt broker
client.on('message', function (topic, payload, packet) {
    console.log(topic+'='+payload);
    io.sockets.emit('mqtt',{'topic':String(topic),
                            'payload':String(payload)});
});

receiver.html
<!doctype html>
<html lang="en">
<head>
<meta charset="UTF-8">
<h1>Real Time</h1>
<style>
body {
    background-color: #666;
    margin: 10px;
}

/*! Light */
#light {
    background-color: #000;
    box-shadow: 0 0 5px rgba(0,0,0, .8);
    overflow: hidden;
    padding: 0 0 4px;
    width: 40px;
}

#light span {
    border-radius: 50px;
    display: block;
    height: 30px;
    margin: 4px auto 0;
    opacity: .5;
    width: 30px;
}

/*! Light colours */
#red    { background-color: red; }
#orange { background-color: orange; }
#green { background-color: green; }

/*! Active states */
#light span.active    { opacity: 1; }
#light #red.active    { box-shadow: 0 0 10px red; }
#light #orange.active { box-shadow: 0 0 10px orange; }
#light #green.active { box-shadow: 0 0 10px green; }

#bulb    { background-color: red; }

/*! Active states */
#light span.On    { opacity: 1; }
#light #bulb.On    { box-shadow: 0 0 10px red; }

/*! Toggle button */
button {
    margin-top: 10px;
}

</style>
<script src="http://localhost:8080/socket.io/socket.io.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.3/jquery.min.js"></script>

<script>
$(document).ready(function() {
        var id_sl;

        $('#btn_sl').on('click', function() {

            var self_sl = $('.active');

            //Check if another element exists after the currently active one otherwise
            //find the parent and start again
            if (self_sl.next().length) {
                id_sl = self_sl.next().attr('id');
            } else {
                id_sl = self_sl.parent().find('span:first').attr('id');
            }

            socket.emit('publish', {topic:"led",payload:id_sl});
        });

        $('#btn_chng').on('click', function() {

            var state = $(this).val();
            socket.emit('publish', {topic:"state",payload:state});

        });

    });
</script>
<script>
var socket = io.connect('http://localhost:8080');
socket.on('connect', function () {
    socket.on('mqtt', function (msg) {

      console.log(msg.topic+' '+msg.payload);

      if(msg.topic == 'led'){

        var self = $('.active');
        self.removeClass('active');
        $('#'+msg.payload).addClass('active');

      }
      if(msg.topic == 'state'){

        if(msg.payload == 'On'){

          $('#bulb').removeClass('On');
          $('#btn_chng').val('Off');

        } else if(msg.payload == 'Off'){

          $('#bulb').addClass('On');
          $('#btn_chng').val('On');

        }

      }


    });
    socket.emit('subscribe',{topic:'led'});
    socket.emit('subscribe',{topic:'state'});
});
</script>
</head>

<body>
<div class='table'>
    <div id="light">
        <span class="active" id="red"></span>
        <span id="orange"></span>
        <span id="green"></span>
        </div>
    <button id="btn_sl">Switch Light</button>
</div>
<div class='table'>

    <div id="light">
        <span class="On" id="bulb"></span>
    </div>
    <button id="btn_chng" value="On">Change State</button>
</div>
</body>

</html>

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Feb 3, 2018

Setup a Mosquitto MQTT Server - Ubuntu

Node MQTT Simple example

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