Ultrasonic Sensor HC-SR04

The HC-SR04 Ultrasonic Sensor is a popular and low-cost distance sensor commonly used in robotics, automation, and DIY electronics projects. It uses sound waves to measure the distance between the sensor and an object.

How It Works:

• It sends out an ultrasonic pulse (at 40kHz) from the trigger (TRIG) pin.
• The sound reflects off an object and returns to the echo (ECHO) pin.
• By calculating the time it takes for the echo to return, you can determine the distance.

Specifications:

Voltage 5V DC

Measuring Range 2 cm – 400 cm

Accuracy ±3 mm

Measuring Angle 15 degrees

Signal Type Digital (time pulse width)

Dimensions 45mm x 20mm x 15mm

Pinout:

VCC 5V Power Supply

TRIG Trigger input (start signal)

ECHO Echo output (pulse duration)

GND Ground

Sample Arduino Code:

const int trigPin = 9;
const int echoPin = 10;
long duration;
int distance;

void setup() {
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  Serial.begin(9600);
}

void loop() {
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);

  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  duration = pulseIn(echoPin, HIGH);
  distance = duration * 0.034 / 2;

  Serial.print("Distance: ");
  Serial.print(distance);
  Serial.println(" cm");

  delay(500);
}

Applications or Projects:

• Obstacle detection in robots
• Smart parking systems
• Liquid level sensing
• Automated door opening
• Distance measurement displays

Origin:- China

Brand:- Generic