#define trigerPin 13
#define echoPin 12
#define ledPin 4
#define speakerPin 11
#define pitch 262
double duration, distance;

void setup() {
  // put your setup code here, to run once:
  pinMode(trigerPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(ledPin, OUTPUT);
  pinMode(speakerPin, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  digitalWrite(trigerPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigerPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigerPin, LOW);
  delayMicroseconds(2);

  duration =pulseIn(echoPin,HIGH);

  distance=(duration/2)*0.0343;

  if (distance < 200) {
    digitalWrite(ledPin, HIGH);
    tone(speakerPin,pitch);
    delay(300);
    digitalWrite(ledPin, LOW);
    noTone(speakerPin);
    delay(300);
  }
  else {
    digitalWrite(ledPin, LOW);
    noTone(speakerPin);
  }

}