/*Before attempting the project try to get some knowledge

about the HC-SR04 Ultrasound Sensor and Arduino.

Abhyuday Tripathi */

long duration; // defining variables for time taken by the wave to comeback after emission.

float distance;// defining variable for distance that has to be measured by the sensor.

int triggerPin = 13;

int echoPin = 11;

void setup() {

pinMode(triggerPin, OUTPUT);//initialising triggerPin as OUTPUT.

pinMode(echoPin, INPUT); //initialising echoPin as INPUT.

Serial.begin(9600); //Activating the Serial at 9600 baud.

}

void loop() {

digitalWrite(triggerPin, LOW); //triggerPin at LOW initially.

delayMicroseconds(2);

digitalWrite(triggerPin, HIGH);// Activating triggerPin to HIGH to generate 8-bit pulse for 10 microseconds.

delayMicroseconds(10);

duration = pulseIn(echoPin, HIGH);// echoPin will be high untill no returning wave has hit it

// that is the duration which is required fo the calculation.

distance = duration*0.03356*0.5 ; //calculating distance in centmeters.

Serial.print("Distance in cm : ");//Serial Monitor will print the distance with interval of one second.

Serial.println(distance);

delay(1000);

}