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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Chapter 6. Interacting with Actuators in Swift

In this chapter, we will write an iOS app in Swift 3 to control actuators with MQTT messages. In addition, we will use Node.js to write code that runs on IoT boards, receives MQTT messages, and controls motors wired to the boards. We will:

  • Understand the requirements to interact with actuators in Swift

  • Define the topics and commands to control actuators

  • Install the CocoaMQTT client library

  • Understand the CocoaMQTT client in Swift 3

  • Connect to the MQTT server and subscribe to topics in Swift

  • Publish messages to target actuators in Swift

  • Process commands that interact with actuators in Node.js

  • Run the iOS app that controls an actuator with MQTT

  • Run the home automation web application

  • Debug events in Swift