Ultrasonic sensor using Arduino

Code

/* 

   CAR PARKING SENSOR

   https://electronicassit.blogspot.in

   ARJUN ARANGIL

   9444868542

*/

// Define pins for ultrasonic and buzzer

int const trigPin = 5;

int const echoPin = 6;

int const buzzPin = 12;

void setup()

{

pinMode(trigPin, OUTPUT); // trig pin will have pulses output

pinMode(echoPin, INPUT); // echo pin should be input to get pulse width

pinMode(buzzPin, OUTPUT); // buzz pin is output to control buzzering

}

void loop()

{

// Duration will be the input pulse width and distance will be the distance to the obstacle in centimeters

int duration, distance;

// Output pulse with 1ms width on trigPin

digitalWrite(trigPin, HIGH);

delay(1);

digitalWrite(trigPin, LOW);

// Measure the pulse input in echo pin

duration = pulseIn(echoPin, HIGH);

// Distance is half the duration devided by 29.1 (from datasheet)

distance = (duration/2) / 29.1;

// if distance less than 40 meter and more than 30 

if (distance <= 20 && distance >= 15) 

{

// Buzz

digitalWrite(buzzPin, HIGH);

delay(100);

digitalWrite(buzzPin, LOW);

delay(300);

}

// if distance less than 15 meter and more than 10 

if (distance <= 15 && distance >= 10) 

{

// Buzz

digitalWrite(buzzPin, HIGH);

delay(100);

digitalWrite(buzzPin, LOW);

delay(200);

}

// if distance less than 10 meter and more than 5

if (distance <= 10 && distance >= 5) 

{

// Buzz

digitalWrite(buzzPin, HIGH);

delay(100);

digitalWrite(buzzPin, LOW);

delay(100);

} 

// if distance less than 5 meter and more than 0

if (distance <= 5 && distance >= 0) 

{

// Buzz

digitalWrite(buzzPin, HIGH);

} else {

// Don't buzz

digitalWrite(buzzPin, LOW);

}

// Waiting 60 ms

delay(10);

}