Learning Robotics using Python - Second Edition

Selecting an ultrasonic sensor

One of the more popular and cheap ultrasonic sensors available is HC-SR04. We are selecting this sensor for our robot because of the following factors:

• Range of detection is from 2 cm to 4 m
• Working voltage is 5 V
• Working current is very low, typically 15 mA

We can use this sensor to accurately detect obstacles. It also works at 5 V. Here is an image of HC-SR04 and its pinout:

Ultrasonic sound sensor (https://www.makerfabs.com/index.php?route=product/product&product_id=72)

The pins and their functions are given as follows:

Pins	Function
Vcc, GND	These are the supply pins of the ultrasonic sensor. ...