Book Image

Internet of Things with Raspberry Pi 3

By : Maneesh Rao
Book Image

Internet of Things with Raspberry Pi 3

By: Maneesh Rao

Overview of this book

This book is designed to introduce you to IoT and Raspberry Pi 3. It will help you create interesting projects, such as setting up a weather station and measuring temperature and humidity using sensors; it will also show you how to send sensor data to cloud for visualization in real-time. Then we shift our focus to leveraging IoT for accomplishing complex tasks, such as facial recognition using the Raspberry Pi camera module, AWS Rekognition, and the AWS S3 service. Furthermore, you will master security aspects by building a security surveillance system to protect your premises from intruders using Raspberry Pi, a camera, motion sensors, and AWS Cloud. We'll also create a real-world project by building a Wi-Fi – controlled robot car with Raspberry Pi using a motor driver circuit, DC motor, and a web application. This book is a must-have as it provides a practical overview of IoT’s existing architectures, communication protocols, and security threats at the software and hardware levels—security being the most important aspect of IoT.
Table of Contents (11 chapters)

Pulse-width modulation

Before we proceed further to wire up our bot and do the programming, we will understand an important concept of PWM. In our project, PWM is used to control the speed of the DC motor.

So, what is PWM? PWM is a technique of generating an output signal from a digital source that behaves like an analog signal. It means that we can control analog circuitry or analog devices using a digital input source. This technique is used in a wide variety of applications like measurements, communication, and power control.

Let's first understand the difference between analog and digital signals.

Analog signal

An analog signal has continuous and varying value over any time interval, with infinite resolution in time...