HC SR04 Ultrasonic Sensor

This is a HC SR04 Ultrasonic Sensor. It works on the principle of emitting of high frequency sound waves. Now, the receiver captures the reflection of this sound waves. The controller on this Ultra Sonic Sensor modules calculates the time between transmitting and receiving of sound waves.

The HC SR04 Ultrasonic Sensor module when receives a pulse on the trigger pin, transmits the high frequency sound wave. And after a delay of 10 micro seconds, the receiver output is available on the echo pin.

The time of the reflection of the signal is detectable using pulseIn() function of Arduino. The distance is measurable by the reflection time of signal.

The distance calculation is as per this formula : (reflection Time) * 0.034 / 2.

The above formula will give the distance result in centimeter

Specifications:

• Power Supply: 5 VDC
• Quiescent Current: <2 mA
• Effectual Angle: < 15°
• Measuring Distance: 2 to 500 cm
• Resolution: 0.3 cm

Applications:

• Measuring Distance
• Automatic Hand Sanitizer Dispenser