const int trigPin = 9;
const int echoPin = 10;
const int buzzerPin = 6;
const int ledPin = 7;

long duration;
int distance;

void setup() {
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(buzzerPin, OUTPUT);
  pinMode(ledPin, OUTPUT);
  Serial.begin(9600);
}

void loop() {
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  
  duration = pulseIn(echoPin, HIGH);
  distance = duration * 0.034 / 2;
  
  if (distance <= 10) {
    tone(buzzerPin, 1000);

    unsigned long startTime = millis(); 
    while (millis() - startTime < 10000) {
      digitalWrite(ledPin, HIGH);
      delay(250);
      digitalWrite(ledPin, LOW);
      delay(250);
    }

    noTone(buzzerPin);

  } else {
    digitalWrite(ledPin, LOW);
    noTone(buzzerPin);
  }
  delay(500);
}