Arduino codes for ultrasonic sensor HC-SR04

Ultrasonic sensor comes very handy for small projects. It can be used for making radar, measuring distance, different types of  alarm system. You can download ultrasonic sensor HC-SR04 datasheet. Arduino connection with ultrasonic sensor is shown in picture.

Arduino code is given below:

void setup()

{

  pinMode(11,OUTPUT);

  pinMode(12,INPUT);

  Serial.begin(9600);

}

void loop()

{

  digitalWrite(11,HIGH);

  delayMicroseconds(30);

  digitalWrite(11,LOW);

  delayMicroseconds(2);

  int a=pulseIn(12,HIGH);//gives time after which high pulse is coming

  int d=(a*0.034)/2;

  Serial.print(d);//show value in serial monitor

  Serial.println(" cm");

  delay(50);

  }

For any querry ask in comment.