Sonar Ultrasonic Sensor (HC-SR04)

• Working Voltage DC 5 V
• Working Current 15mA
• Working Frequency 40Hz
• Max Range 4m
• Min Range 2cm
• Measuring Angle 15 degree
• Trigger Input Signal 10uS TTL pulse

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. Test distance = (high level time × velocity of sound (340M/S).