The HC-SR04 Ultrasonic Sensor is a widely used distance measurement module that uses ultrasonic waves to detect objects and calculate distance accurately. It works by emitting ultrasonic pulses and measuring the time taken for the echo to return.

With a detection range of 2cm to 400cm, the HC-SR04 provides reliable and precise distance measurement, making it ideal for robotics, obstacle avoidance, and automation systems.

The module is easy to interface with Arduino and other microcontrollers using simple trigger and echo pins. Its low cost, high accuracy, and ease of use make it one of the most popular sensors for DIY and professional projects.