Arduino (any compatible board), HC-SR04 Ultrasonic Sensor, Jumper Wires, Breadboard (optional), #Circuit Diagram: Trig Pin of HC-SR04 → Arduino Pin 9, Echo Pin of HC-SR04 → Arduino Pin 10, VCC of ...

Ultrasonic Sensor Measurement: The HC-SR04 ultrasonic sensor measures the distance to an object by emitting a sound wave and measuring the time it takes for the echo to return. The sensor is connected ...

You can test the circuit with a function generator and a 40-kHz ultrasonic transmitter or a suitable tweeter. An alternative signal source is, for example, the inexpensive Grove ultrasonic distance ...