Ultrasonic Sensor

An ultrasonic sensor, such as the HC-SR04, is an electronic sensor used to measure the distance between the sensor and an object. It works by sending out high-frequency ultrasonic sound waves and measuring the time taken for the waves to return after hitting an object. The sensor has four pins: VCC, Trigger, Echo, and GND. It is commonly used with an Arduino UNO for projects such as obstacle-avoiding robots, smart parking systems, automatic gates, distance measurement, and security systems.