Book Image

MQTT Essentials - A Lightweight IoT Protocol

5 (1)
Book Image

MQTT Essentials - A Lightweight IoT Protocol

5 (1)

Overview of this book

This step-by-step guide will help you gain a deep understanding of the lightweight MQTT protocol. We’ll begin with the specific vocabulary of MQTT and its working modes, followed by installing a Mosquitto MQTT broker. Then, you will use best practices to secure the MQTT Mosquitto broker to ensure that only authorized clients are able to publish and receive messages. Once you have secured the broker with the appropriate configuration, you will develop a solution that controls a drone with Python. Further on, you will use Python on a Raspberry Pi 3 board to process commands and Python on Intel Boards (Joule, Edison and Galileo). You will then connect to the MQTT broker, subscribe to topics, send messages, and receive messages in Python. You will also develop a solution that interacts with sensors in Java by working with MQTT messages. Moving forward, you will work with an asynchronous API with callbacks to make the sensors interact with MQTT messages. Following the same process, you will develop an iOS app with Swift 3, build a website that uses WebSockets to connect to the MQTT broker, and control home automation devices with HTML5, JavaScript code, Node.js and MQTT messages
Table of Contents (16 chapters)
MQTT Essentials - A Lightweight IoT Protocol
Credits
About the Author
Acknowledgment
About the Reviewer
www.PacktPub.com
Customer Feedback
Dedication
Preface

Understanding the requirements


Now, we want to be able to control home automation in any web browser. Hence, we have to be able to send and receive MQTT messages in these web browsers. There are no W3C standards for implementing MQTT support in web browsers. No major web browser has implemented direct MQTT support. Luckily, MQTT over WebSockets makes it possible for us to encapsulate MQTT messages on WebSockets and use any modern web browser that supports WebSockets as a client for an MQTT server that also provides support for WebSockets.

Tip

Mosquitto provides support for MQTT over WebSockets. However, we must enable this support by making changes in the configuration file. In case you don't want to work with Mosquitto, you must make sure that the MQTT server you use provides support for MQTT over WebSockets to work with this example.

First, we will create a web page with HTML 5 and JavaScript code to generate an MQTT client that will act as a publisher and subscriber. We will connect a JavaScript...