//define variable

#define trigerPin 12
#define echoPin 12
#define ledPin 2
#define speakerPin 10
#define pitch 262

double duration,distance;
void setup(){
  //setup Sensor
  Serial.begin(9600);
  pinMode(trigerPin, OUTPUT);
  pinMode(echoPin, INPUT);
  
  //setup Led
  pinMode(ledPin, OUTPUT);

  //Setup Speaker
  pinMode(speakerPin, OUTPUT);


}

void loop(){
      //looping sensor
      digitalWrite(trigerPin, LOW);
      delayMicroseconds(2);
      digitalWrite(trigerPin, HIGH);
      delayMicroseconds(10);
      digitalWrite(trigerPin, LOW);

      //get duration
      duration=pulseIn(echoPin, HIGH);
      
      //get distance
      distance=(duration/2)*0.0343;

      //consider that the door width is 200cm
      if(distance==200){
        digitalWrite(ledPin, HIGH);
        tone(speakerPin,pitch);
        delayMicroseconds(300);

        digitalWrite(ledPin, LOW);
        noTone(speakerPin);
        delayMicroseconds(300);
      }else{
        digitalWrite(ledPin,LOW);
        noTone(speakerPin);
      }                                                                            
}