Ultrasonic Sensor HC-SR04 is used to measure distance. We can
find precise distance to an object from sensor, or can used to detect when
something is within range of the sensor. It can measure distance with high
accuracy from 2cm to 400 cm. Its operation is not affected by sunlight or black
material .Because it uses sound to measure distance.
Ultrasonic range finder measure distance by emitting a pulse
of ultrasonic sound that travels through the air until it hits an object. It
measure how long it takes the sound pulse to travel in its round trip journey
back to the sensor when the pulse hits the object. Then it sends an electrical
signal to the Arduino with information about how long it took for the sonic
pulse to travel.
Ultrasonic range finder has 2 transducers.
- Transmitting transducer
- Receiving transducer