The HC-SR04 ultrasonic sensor uses sonar waves to determine distance to an object. It offers excellent range accuracy and stable readings in an easy-to-use and small package. Its operation is not affected by sunlight or black material although acoustically soft materials like cloth can be difficult to detect as they absorb the sound waves.
To use it output a 10us HIGH signal to the TRIGGER line to start the detection. After this module will send out eight 40kHz sound waves. If echo is detected the ECHO line will output a pulse. By measuring the length of this pulse, distance can be determined using the following formula: distance = pulse length * speed of sound (340m/s) / 2.
Working voltage: 5V DC
Quiescent Current : < 2mA Angle: <15° Ranging Distance : 2cm – 450 cm Accuracy: ~0.3cm
1 x HC-SR04 ultrasonic sensor module