const int trigPin=11;
const int echoPin= 12;
long duration;
int distance;
int Buzzer= 4;
int LED_1=13;
int LED_2=10;
int LED_3=9;




void setup() {
  // put your setup code here, to run once:
  pinMode(trigPin,OUTPUT);
  pinMode(echoPin,INPUT);
  pinMode(Buzzer,OUTPUT);
  pinMode(LED_1,OUTPUT);
  pinMode(LED_2,OUTPUT);
  pinMode(LED_3,OUTPUT);
Serial.begin(9600);
}

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

  digitalWrite(trigPin,HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin,LOW);

  duration = pulseIn(echoPin,HIGH);
  distance=duration*0.034/2;
  Serial.print("Distance :");
  Serial.println(distance);
    Serial.println("cm");

  if (distance < 7){
   digitalWrite(Buzzer,HIGH);
   digitalWrite(LED_1,HIGH);
   delay(100);
   digitalWrite(Buzzer,LOW);
   digitalWrite(LED_1,LOW);
   delay(100);
  
   
   
  }

  else if (distance > 7 && distance < 15){
    digitalWrite(Buzzer,HIGH);
   digitalWrite(LED_2,HIGH);
   delay(100);
   digitalWrite(Buzzer,LOW);
   digitalWrite(LED_2,LOW);
   delay(100);
  }
  else if (distance > 15){
    digitalWrite(Buzzer,HIGH);
   digitalWrite(LED_3,HIGH);
   delay(100);
   digitalWrite(Buzzer,LOW);
   digitalWrite(LED_3,LOW);
   delay(100);
  

  }
  
  delay(100);
  
}