http://www.embeddedadvice.com/t/thingsboard-io-sending-and-recieving-data/371

var mqtt = require(‘mqtt’);
const ACCESS_TOKEN = process.argv[2];

var client = mqtt.connect(‘mqtt://demo.thingsboard.io’,{
username: ACCESS_TOKEN
});

var controlValue,
realValue = 25;

client.on(‘connect’, function () {
console.log(‘connected’);
client.subscribe(‘v1/devices/me/rpc/request/+’);
console.log(‘Uploading temperature data once per second…’);
setInterval(publishTelemetry, 1000);
});

client.on(‘message’, function (topic, message) {
console.log('request.topic: ’ + topic);
console.log('request.body: ’ + message.toString());
var requestId = topic.slice(‘v1/devices/me/rpc/request/’.length),
messageData = JSON.parse(message.toString());
if (messageData.method === ‘getValue’) {
if(controlValue === undefined) {
client.publish(‘v1/devices/me/rpc/response/’ + requestId, JSON.stringify(realValue));
} else {
client.publish(‘v1/devices/me/rpc/response/’ + requestId, JSON.stringify(controlValue));
}
} else if (messageData.method === ‘setValue’) {
controlValue = messageData.params;
console.log('Going to set new control value: ’ + controlValue);
} else {
client.publish(‘v1/devices/me/rpc/response/’ + requestId, message);
}
});

function publishTelemetry() {
emulateTemperatureChanging();
client.publish(‘v1/devices/me/telemetry’, JSON.stringify({temperature: realValue}));
}

function emulateTemperatureChanging() {
if(controlValue !== undefined) {
if(controlValue >= realValue) {
realValue += (Math.random() + (Math.abs(controlValue - realValue)/30));
} else {
realValue -= (Math.random() + (Math.abs(controlValue - realValue)/30));
}
}
}