Ultrasonic ranging module HC – SR04 provides 2cm – 400cm non-contact measurement function, the ranging accuracy can reach to 3mm. The modules includes ultrasonic transmitters, receiver and control circuit.
The basic principle of work:
1. Using IO trigger for at least 10us high level signal.
2. The Module automatically sends eight 40 kHz and detect whether there is a pulse signal back.
3. IF the signal back, through high level , time of high output IO duration is the time from sending ultrasonic to returning.
4. Test distance = (high level time?velocity of sound (340M/S) / 2.
– Power Supply :5V DC
– Quiescent Current : <2mA
– Working Current: 15mA
– Effectual Angle: <15?
– Ranging Distance : 2cm ? 400 cm or 1″ – 13ft
– Resolution : upto 0.3 cm
– Dimension: 45mm x 20mm x 15mm