Ultrasonic Sensor (HC-SR04)

HC-SR04 Sensor Features

• Operating voltage: +5V
• Theoretical  Measuring Distance: 2cm to 450cm
• Practical Measuring Distance: 2cm to 80cm
• Accuracy: 3mm
• Measuring angle covered: <15°
• Operating Current: <15mA
• Operating Frequency: 40Hz

More details can be found in the HC-SR04 ultrasonic sensor datasheet attached at the bottom of this article.

Distance = Speed × Time

The Ultrasonic transmitter transmits an ultrasonic wave, this wave travels in air and when it gets objected by any material it gets reflected back toward the sensor this reflected wave is observed by the Ultrasonic receiver module