Mqtt JSON to MAM

This module would help us to read the data that is comming form MQTT parse to a Json and then send it to the Tangle as MAM.

Installation

To start usring first we ned to give the next command

$ cd XDK110-Bosch/C/IOTA-XDK110-MAM/IOTAMAM/
$ npm install

Explanation

We need to modify the next file so we can connect to mqtt.

The file is named index.js

$ nano index.js

Let understand this code. See the comments on the code.

//We define that this program is going to execute in a strict mode
'use strict'

 //Now we need to bring some libraries to work with MAM, we need to use public, private or restricted. Then bring the iota.lib.js
 //this one we previously download it.
const MAM_public = require('./lib/attachDataPublic.js')
const MAM_private = require('./lib/attachDataPrivate.js')
const MAM_restricted = require('./lib/attachDataRestricted.js')
const IOTA = require('iota.lib.js')
//We need to define 2 objets one a IOTA and a mqtt
const iota = new IOTA()
const mqtt = require ('mqtt');

//We need to define the mqtt connection
//We user:password@mqttbroker:port
var client  = mqtt.connect('mqtt://xdk110:[e-mail]:1883');
var jsonData = null;

//This fuction would parse the string to json
function getmyjson(myjson){
  jsonData = JSON.parse(myjson);
//  console.log(jsonData);
}

//connect and subscribe to topic
client.on('connect', function () {
  client.subscribe('XDK110/sensor/status');

//  console.log('client has subscribed successfully');
});


// get data when we receive something from the subscribe
client.on('message', function (topic, message){
  //console.log('Received message %s %s', topic, message)
  getmyjson(message);
});

let timeLoop,date,
    i=1

if( process.argv[2] == undefined){          //Getting the time in seconds for the loop
  timeLoop = 60000                       //default 1 minute
} else {
  timeLoop = process.argv[2]*1000
}


//Create a JSON as message and parse to MAM

function start(){
    const time = Date.now();
        let message = { 'Message' : i,
            'id' : jsonData.Ident,
            'location' : {'lat' : 20.674605, 'lng' : -103.393228},
            'timestamp' : time,
            'humidity' :    jsonData.Humidity,
            'pressure' :    jsonData.Pressure,
            'temperature' : jsonData.Temperature,
            'light' : jsonData.Light,
            'noise' : jsonData.Noise,};
    switch(process.argv[3]){                                //Getting the mode of the stream (Public:1, Private:2, Restricted: 3)
        case '1': MAM_public.attach(message);break;
        case '2': MAM_private.attach(message);break;
        case '3': MAM_restricted.attach(message);break;
        default: MAM_public.attach(message)
    }
    console.log('Start sending data to Tangle...')
    let messageS = JSON.stringify(message)
    console.log('Message: %s',messageS)
    console.log('Message in trytes: ' + iota.utils.toTrytes(messageS))
    console.log('--------------------------------------------------------------------------------------------------------------------')
    i++
}

setInterval(function(){
    start()
},timeLoop)