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)

Ultrasonic sensors

Ultrasonic sensors are used for noncontact proximity, object detection, and distance measurement. As the name suggests, these sensors use ultrasonic waves as a source to detect the object and its distance. The sensor measures the distance to an object by calculating the time between emission and reception of ultrasonic waves. Ultrasonic waves are very accurate over a short distance and do not create disturbances as they are inaudible to human ears.

The sensor has both an ultrasonic transmitter and receiver. The sensor works on the same principle as that of sonar/radar, which evaluates the presence of an object by listening to the echo of sound waves or radio waves reflected from the object. The sensor emits a burst of high frequency, short-wavelength ultrasonic rays, which when echoed back from the object are received at the sensor. The time difference between...