Book Image

Mastering Internet of Things

By : Peter Waher
Book Image

Mastering Internet of Things

By: Peter Waher

Overview of this book

The Internet of Things (IoT) is the fastest growing technology market. Industries are embracing IoT technologies to improve operational expenses, product life, and people's well-being. Mastering Internet of Things starts by presenting IoT fundamentals and the smart city. You will learn the important technologies and protocols that are used for the Internet of Things, their features, corresponding security implications, and practical examples on how to use them. This book focuses on creating applications and services for the Internet of Things. Further, you will learn to create applications and services for the Internet of Things. You will be discover various interesting projects and understand how to publish sensor data, control devices, and react to asynchronous events using the XMPP protocol. The book also introduces chat, to interact with your devices. You will learn how to automate your tasks by using Internet of Things Service Platforms as the base for an application. You will understand the subject of privacy, requirements they should be familiar with, and how to avoid violating any of the important new regulations being introduced. At the end of the book, you will have mastered creating open, interoperable and secure networks of things, protecting the privacy and integrity of your users and their information.
Table of Contents (24 chapters)
Title Page
Copyright and Credits
Packt Upsell

Publishing sensor data

Now that we have a live connection, we're ready to publish sampled sensor data. We will first need some member variables. These will store last values, last-published values, and the timestamps of last-published values:

private double? lastLight = null; 
private bool? lastMotion = null; 
private double? lastPublishedLight = null; 
private bool? lastPublishedMotion = null; 
private DateTimelastLightPublishTime = DateTime.MinValue; 
private DateTimelastMotionPublishTime = DateTime.MinValue; 

From our sampling and event methods where we receive and calculate our most recent sensor data, we call two new methods: PublishLight() and PublishMotion(). To illustrate different ways of publishing data, these two methods will publish the corresponding sensor data fields on individual topics, as strings. They will then individually call PublishLastJson(), which will publish both fields on one topic, as a JSON object string.

Choosing relevant values

Before we publish the data, we need...