HC-SR04 Ultrasonic Sensor Distance Module

HC-SR04 Ultrasonic Sensor Distance Module is a commonly used ultrasonic sensor designed for distance measurement. It is popular in robotics and automation projects due to its accuracy, simplicity, and low cost. 

 The HC-SR04 sensor works on the principle of echolocation, similar to how bats navigate. It emits an ultrasonic wave at a frequency of 40 kHz, which travels through the air and bounces back upon hitting an obstacle. The sensor then calculates the time taken for the echo to return and converts this into a distance measurement.