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
Dedication
Packt Upsell
Contributors
Preface
Index

Converting to a physical quantity


It is not sufficient for a sensor to have a numerical raw value of the measured quantity. It only tells us something if we know something more about the raw value. We must therefore convert it to a known physical unit. We must also provide an estimate of the precision (or error) the value has.

Note

A sensor measuring a physical quantity should report a numerical value, its physical unit, and the corresponding precision, or error of the estimate.

To avoid creating a complex mathematical model that converts our measured light intensity into a known physical unit, which would go beyond the scope of this book, we convert it to a percentage value. Since we've gained a factor of five of precision using our averaging calculation, we can report two decimals of precision, even though the input value is only 1,024 bits, and only contains one decimal of precision:

   double Light = (100.0 * AvgA0) / 1024; 
   MainPage.Instance.LightUpdated(Light, 2, "%"); 
}