HCP IoT MQTT service

[Murali_Shanmu]

Hi,

I am trying to use MQTT Websockets (now available in HCP IoT Service) to push data from my device to HCP IoT Services. I am able to test this using the MQTT Websockets Test client. I am after a sample code (nodejs/python) which can show me how to publish a message to the device which is registered in IoT services. I cant get my code to work.

//Program testmqtt.js

var mqtt

= require('mqtt');

var host = 'iotmmsc59c97a90.ap1.hana.ondemand.com';

var device = '0ccc712a-eac4-42ba-af2e-02528938a3ae';

var oAuthToken = 'e862e126d2f28ab0cff167224aecf83';

var messageType = '1a96769b7fda1b7c5433';

var path = '/com.sap.iotservices.mms/v1/api/ws/mqtt';

var options = {

    extraHeaders: {

	'Authorization': 'Bearer ' + oAuthToken,
	'Content-Type': 'application/json;charset=utf-8'

    } 

};

var client = mqtt.connect('wss://' + host + path, options);

client.on('connect', function () {

  console.log("about to connect")

  var jsonData = {

	"mode": "async",
	"messageType": messageType,
	"messages": [{"temp":99,"light":85}]

    };

  var strData = JSON.stringify(jsonData);

  client.publish('iot/data/0ccc712a-eac4-42ba-af2e-02528938a3ae', strData);

});

client.on('message', function (topic, message) {

  // message is Buffer

  console.log(message.toString());

  client.end();

});

Thanks,

Murali.

[anton_levin · Accepted solution]

Hi Murali,

from a description I didn't get what exactly issue are you facing with. Did you also try the Python (MQTT Paho lib) example from StarterKit [1] ? Maybe that one will clarify it.

Regards,

Anton

[1] iot-starterkit/src/examples/python/mqtt-over-wss at master · SAP/iot-starterkit · GitHub

[Murali_Shanmu · Accepted solution]

Hi Anton,

Thanks for that. I didn't notice python scripts in github. I will try it out. I am assuming there is none readily available for nodejs.

Thanks,

Murali.

[anton_levin · Accepted solution]

No, not to my knowledge.

[Murali_Shanmu · Accepted solution]

Ok, Here is sample code snippet in nodejs which I obtained from a colleague. This works perfect.

// ========================================================================

// CONFIGURATION

// ========================================================================

var my_account_id='c59c97a90';

var my_device_id='0ccc712a-eac4-42ba-af2e-02528938a3ae';

var my_oauth_token='e862e126d2f28ab0cff167224aecf83';

// ========================================================================

var endpoint = 'wss://iotmms'+my_account_id+'.ap1.hana.ondemand.com:443/com.sap.iotservices.mms/v1/api/ws/mqtt';

var options = {

    keepalive: 60,

    username: my_device_id,

    password: my_oauth_token,

    connectTimeout: 5 * 1000,

    clientId: my_device_id,

    protocolId: 'MQIsdp',

    protocolVersion: 3,

    clean: true,

    will: null

};

console.log(options);

// ========================================================================

var mqtt    = require('mqtt');

var client  = mqtt.connect(endpoint, options);

client.on('connect', function () {

    console.log('connected!');

    var data = {"mode":"async","messageType":"1a96769b7fda1b7c5433","messages":[{"temp":11,"light":88}]};

    client.publish('iot/data/'+my_device_id, JSON.stringify(data));

    console.log(JSON.stringify(data));

});

client.on('error', function () {

    console.log('error!');

});

client.on('offline', function () {

    console.log('offline!');

});

client.on('close', function () {

    console.log('close!');

});

client.on('message', function (topic, message) {

  // message is Buffer

  console.log(message.toString());

  //client.end();

});