Ultrasonic sensor act like a bats.
- The HC-SR04 ultrasonic sensor uses sonar to determine distance.
- It offers excellent range detection with high accuracy and stable reading.
- It offers range detection from 2cm to 400 cm or 1 to 13 feet.
- Ultrasonic sensor consist of Transmitter and Receiver module.
Working
- Sensor trigger pin must receive a pulse of high (5V) for 10us.
- Then sensor will transmit out 8 cycle of 40kHz ultrasonic burst.
- Sensor wait for the reflected ultrasonic burst.
- When the sensor detected ultrasonic from receiver, it will set the Echo pin to high (5V) and delay.
- Delay period is a width which proportion to distance.
- To obtain the distance, measure the width (Ton) of Echo pin.
Timing Diagram
Distance Calculation
- Time = Width of Echo pulse, in uS (micro second).
- Distance in centimeters = Time / 58.
- Distance in inches = Time / 148.
Features
- Power Supply :+5V DC.
- Quiescent Current : <2mA.
- Working Current: 15mA.
- Effectual Angle: Less than 15 Degree.
- Ranging Distance : 2cm to 400 cm/1 to 13ft.
- Resolution : 0.3 cm.
- Measuring Angle: 30 degree.
- Trigger Input Ppse width: 10uS.
- Dimension: 45mm x 20mm x 15mm.
Hardware Required
- Ultrasonic HC-SR04.
- 8051 MicroController.
Pin Diagram
- VCC: +5VDC.
- Trig : Trigger (INPUT).
- Echo: Echo (OUTPUT).
- GND: GND.
Circuit
