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)


L293D is an integrated circuit chip most commonly used to drive the DC motor/stepper motor/gear motor. This IC consists of two H-bridges that can drive two DC motors simultaneously and in both clockwise and anticlockwise direction. It acts as an interface between the Raspberry Pi (or any other microprocessor) and the motor.

The DC motor needs a significant amount of current to start, which the Raspberry Pi is unable to provide as an output through GPIO. For example, a 5V DC motor needs around 300 to 400 mA current, which is way beyond what is available in the Raspberry Pi's GPIO, and if we directly connect the motor to the GPIO, it can damage the Pi. So, it is recommended you avoid directly connecting of the motor to Pi.

Let's look at the pin diagram for IC L293D to get an understanding of its operation:

L293D has a 16-pin configuration. There are two Enable pins...