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
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Testing the MQTT TLS configuration with MQTT.fx

Now, we will use the MQTT.fx GUI utility to generate another MQTT client that uses an encrypted connection to publish messages to the same topic, sensors/drone01/altitude. We have to make changes to the connection options to enable TLS and specify the certificate authority certificate file. Follow the next steps:

  1. Launch MQTT.fx, select local mosquitto in the dropdown located on the upper-left corner, and click on the configuration icon on the right-hand side of this dropdown and on the left-hand side of the Connect button. MQTT.fx will display the Edit Connection Profiles dialog box with different options for the connection profile named local mosquitto.

  2. Change the value specified in Broker Port from 1883 to 8883 .

  3. Press the SSL/TLS button.

  4. Activate the Enable SSL/TLS checkbox.

  5. Activate the CA certificate file radio button.

  6. Enter or select the full path to the ca.crt file that you created in the certificates folder in the CA Certificate File textbox...