An ultrasonic sensor is an electronic device that measures distance or detects the presence of objects by emitting and receiving ultrasonic sound waves. These sensors operate on the principle of echolocation, similar to how bats and dolphins navigate their environments. The sensor emits high-frequency sound waves, which travel through the air and bounce off any nearby objects. The sensor then listens for the return of these sound waves, or echoes, and calculates the time taken for the wave to travel to the object and back.

This specific sensor is designed to work with 5V and is activated with a 10µs pulse on the trigger pin. An output signal is returned on the echo pin immediately once the sensor receives the echo. Since the speed of sound is relatively stable, the time between the pulse and the echo can be used to determine distance.

These are the simplest version of the Ultrasonic sensor we sell – they can achieve read ranges of up to 4 meters (walls and other very large objects) but tend to max out around 2.5 meters when the object is roughly the size of a person.