The HC-SR04 Ultrasonic Sensor is widely used for non-contact distance measuring from 2cm – 400cm. The module includes ultrasonic transmitters, receiver and a control circuit.
The module works in the following way:
1. Send a 10 µs high level pulse to the trigger (TRIG) pin of the module from a microcontroller.
2.The module will automatically send eight internally generated 40khz pulses from the transmitter and receive the echo at the receiver.
3. A TTL level pulse will be sent from ECHO pin of the module. The width of the pulse is in proportion to the distance measured. Distance = (high level time * sound velocity / 2) . Generally sound velocity = 340 m/s
1. Working Voltage: 5 VDC
2. Static current: Less than 2mA
3. Operating Current: 15mA
3. Output signal: Electric frequency signal, high level 5V, low level 0V
4. Sensor angle: Not more than 15 degrees
5. Detection distance: 2cm-400cm
6. Precision: Up to 0.3cm
7. Input trigger signal: 10us TTL impulse
8. Echo signal: Output TTL PWL signal