// def pin numbers
const int trigPin = 9;
const int echoPin = 10;
const int buzzer = 11;
const int ledPin = 13;

//def var
long duration;
int distance;
int safetyDistance;

void setup() {
  pinMode(trigPin, OUTPUT); // set trigPin as Output
  pinMode(echoPin, INPUT); // set echopin as input
  pinMode(buzzer, OUTPUT);
  pinMode (ledPin, OUTPUT);
  Serial.begin(9600); // Starts serial comm

}

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

  //sets trigpin on high state for 10 microsecs
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

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

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

  safetyDistance = distance;
  if (safetyDistance <= 5){
    digitalWrite(buzzer, HIGH);
    digitalWrite(ledPin, HIGH);
  } else{
    digitalWrite(buzzer, LOW);
    digitalWrite(ledPin, LOW);
  }
  

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

  // put your main code here, to run repeatedly:

}