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

Connecting an LED

An alternative to working with the alternating current (AC) is to use a low-power direct current (DC) source and an LED to simulate a lamp. You can connect the COM connector to a resistor and an LED, and then to ground (GND) on one end, and the NO directly to the 5V or 3.3V source on the Raspberry Pi on the other end. The size of the resistor is determined by how much current the LED needs to light up, and the voltage source you choose. If the LED needs 20 mA, and you connect it to a 5V source, Ohms Law tells us we need an R = U/I = 5V/0.02A = 250 Ω resistor. The following figure illustrates this:

Connecting a LED