The HC-SR04 ultrasonic sensor can send eight 40 kHz and detect whether there is any pulse signal back.If it back, a high level signal will be outputed by IO, and the duration of the signal is the time from sending ultrasonic to returning HC-SR04 Test Distance : high level time velocity of sound (340M/S) /2 HC-SR04 Power Supply : 5V DC; Quiescent Current : <2mA,; Effectual Angle: <15° ; Detection Distance : 2cm~500 cm; Resolution : 0.3 cm Equipped with anti-reverse pin socket – making the wiring much tighter and convenient; 4-pin anti-reverse cable also included.
