Guide to IoT protocols

Follow are the popular IoT protocols these days

1. MQTT
2. CoAP


Introduction for MQTT and example



Nowadays we hear a lot about MQTT with IoT based projects. Let's see actually what is MQTT with simple examples in your Pc and later you can use them for your future IoT projects.


MQTT is a publish/subscribe protocol that allows edge-of-network devices to publish to a broker. Clients connect to this broker, which then mediates communication between the two devices. Each device can subscribe, or register, to particular topics. When another client publishes a message on a subscribed topic, the broker forwards the message to any client that has subscribed.

Hey let's make the idea so simple

As an example imagine you have a plant. You put 3 sensors to it

temperature sensor, humidity sensor, light intensity sensor

So you need to get these sensor data to your application. Let's use the MQTT protocol to this scenario.

Here we create topics to each sensor

a message broker is a software we have to install to do this stuff. There are many brokers. here I'm using the mosquitto broker

 http://mosquitto.org/

eg:-

temperature sensor                 plant/temp
humidity sensor                       plant/hum
light intensity sensor               plant/light


So these are the topics about each sensor. All the sensor data will be published to these topics in the broker.

So let's move to the client part

The client has to subscribe to these topics to get data from the sensors.

simple they can subscribe to these topics



How to Install in your machine?

 

 Linux 

curl -O http://repo.mosquitto.org/debian/mosquitto-repo.gpg.key
sudo apt-key add mosquitto-repo.gpg.key
rm mosquitto-repo.gpg.key
cd /etc/apt/sources.list.d/
sudo curl -O http://repo.mosquitto.org/debian/mosquitto-repo.list
sudo apt-get update

sudo apt-get install mosquitto mosquitto-clients python-mosquitto


sudo /etc/init.d/mosquitto stop


 Windows

http://www.eclipse.org/mosquitto/download/ 

 Let's move to the practice?

eg
In separate terminal windows do the following:
  1. Start the broker:
    mosquito
  2. Start the command line subscriber:
    mosquitto_sub -v -t 'plant/temp'
  3. Publish test message with the command line publisher:
    mosquitto_pub -t 'plant/temp' -m 'sensor_val'
As well as seeing both the subscriber and publisher connection messages in the broker terminal the following should be printed in the subscriber terminal:
plant/temp sensor_val

this is how MQTT works simply

The MQTT protocol allows your SCADA system to access IIoT data. MQTT brings many powerful benefits to your process:
  • Distribute information more efficiently
  • Increase scalability
  • Reduce network bandwidth consumption dramatically
  • Reduce update rates to seconds
  • Very well-suited for remote sensing and control
  • Maximize available bandwidth
  • Extremely lightweight overhead
  • Very secure with permission-based security
  • Used by the oil-and-gas industry, Amazon, Facebook, and other major businesses
  • Saves development time
  • Publish/subscribe protocol collects more data with less bandwidth compared to polling protocols

How Does MQTT Work?

MQTT is a publish/subscribe protocol that allows edge-of-network devices to publish to a broker. Clients connect to this broker, which then mediates communication between the two devices. Each device can subscribe, or register, to particular topics. When another client publishes a message on a subscribed topic, the broker forwards the message to any client that has subscribed.
MQTT is bidirectional and maintains stateful session awareness. If an edge-of-network device loses connectivity, all subscribed clients will be notified with the “Last Will and Testament” feature of the MQTT server so that any authorized client in the system can publish a new value back to the edge-of-network device, maintaining bidirectional connectivity.
The lightweights and efficiency of MQTT makes it possible to significantly increase the amount of data being monitored or controlled. Prior to the invention of MQTT, approximately 80% of data was being left at remote locations, even though various lines of business could have used this data to make smarter decisions. Now MQTT makes it possible to collect, transmit, and analyze more of the data being collected.

Who Uses MQTT?

MQTT was originally developed for the low-bandwidth, high-latency data links used in the oil and gas industry. However, MQTT is now used in many applications beyond oil and gas — from controlling smart lighting systems to the Facebook Messenger application. Amazon Web Services recently announced that Amazon Internet of Things (IoT) is based on MQTT, as well. Overall, MQTT appears to be the protocol best suited for the control systems used by industrial organizations, and we can expect that its rapid rate of adoption will only increase in the future.

So i think now you have a good idea about mqtt. Hope your projects will be more fascinated with mqtt.

 

Comments

Post a Comment

Comment

Popular posts from this blog

IOT Greenhouse project part 1

Image
How to build Simple IOT Greenhouse (Part 1) This this project we are going to control a stable environment to the plant inside the greenhouse.  With using mqtt protocols and latest IOT suff. And also we can monitor plant conditions using digital image processing. So let's start this step by step. Part 1 is all about setting up the sensors and hardware part. So what do you need to this project ? Components 1.) Arduino Uno with wifi shield 2.) Raspberry PI 2 Board and wifi adapter. 3.) DHT 21 (AM2301) Temperature and humidity sensor 4.) Soil Moisture Sensor 5.) Light intensity sensor 6.) Water pump 7.) Raspberry PI Camera or web cam for image processing 8.) 16 in to 4 LCD display Don't be scared i'm going to explain bit by bit how to build this system. First of all you have to design the hardware part. plug the sensor to the arduino in correct way. Simple Arduino Code to get sensor data and display here this code is without the arduino w...
Read more

How to fix FirebaseApp with name [DEFAULT] doesn't exist issue with flutter

Image
How to fix FirebaseApp with name [DEFAULT] doesn't exist issue with flutter This is a very common issue when we try to google authenticate our app with flutter. Please check the following are done in your app. Updated the android build.gradle file Updated the android\app build.gradle file Added dependency to pubspec.yaml Placed the google-services.json file Check Updated the android build.gradle file Add the following line to the android/build.gradle file please add the following line to that file. classpath 'com.google.gms:google-services:4.3.2' // Google Services plugin Check Updated the android\app build.gradle file Add following line to the following location apply plugin : 'com.google.gms.google-services' Check Added dependency to pubspec.yaml firebase_auth : ^0.14.0+5 google_sign_in : ^4.0.7 Placed the google-services.json file make sure you have added google-services.json from the firebase...
Read more

Node.js how to work with Serial ports and display data on a beautiful frontend using Highcharts API Part 2

Image
Now you have some basic idea of the technologies we are using here. So let's get our hands dirty. First, we have to set up the Node js libraries correctly to handle the serial data and open a WebSocket. So simple what we here going to do is getting data from USB and put them into a GUI to visualize our data nicely. So for this tutorial, I'm going to use Arduino as my data source. Piratically this will be your sensor or devices which you are using. Here http://www.highcharts.com/  Highcharts makes it easy for developers to set up interactive charts in their web pages. This has good community support and this is best for our works. 1. First step clone this repository https://github.com/akilawickey/nodejs-serial-frontend/tree/master Here is the Arduino sketch sample.ino which I'm using to emulate data which you can find inside the repository 1: /* 2: * This code will emulate USB data 3: * 4: * 5: */ 6: // the setup function run...
Read more