/*
* Ultrasonic Sensor HC-SR04 and Arduino Tutorial
*
* by Dejan Nedelkovski,
* www.HowToMechatronics.com
*
*/

// defines pins numbers
const int trigPin = 9;
const int echoPin = 10;
const int response = 6;

// defines variables
long duration;
int distance;

void setup() {
pinMode(trigPin, OUTPUT); // Sets the trigPin as an Output
pinMode(response, OUTPUT);
pinMode(echoPin, INPUT); // Sets the echoPin as an Input
Serial.begin(9600); // Starts the serial communication

// Clears the trigPin
digitalWrite(trigPin, LOW);
delayMicroseconds(2);
}

void loop() {
// Sets the trigPin on HIGH state for 10 micro seconds
digitalWrite(trigPin, HIGH);
delayMicroseconds(10);
digitalWrite(trigPin, LOW);

// Reads the echoPin, returns the sound wave travel time in microseconds
duration = pulseIn(echoPin, HIGH);

// Calculating the distance
distance= duration*0.034/2;

// Prints the distance on the Serial Monitor
//Serial.print("Distance: ");
//Serial.println(distance);

if (distance < 5){
  Serial.println("0");
  digitalWrite(response, LOW);
}
else{
  Serial.println("1");
  digitalWrite(response, HIGH);
}

delay(500);
}