const int trigPin = 12;
  const int echoPin = 13;

  long duration;
  int distance;
  
void setup() {
  
  pinMode(trigPin, OUTPUT); 
  pinMode(echoPin, INPUT);
  pinMode(11, OUTPUT);
  pinMode(10, OUTPUT);
  pinMode(9, 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;

  Serial.print("Distance: "); 
  Serial.println(distance);
/*
  if(distance<10){
    analogWrite(9, 255);
    analogWrite(10,0);
    analogWrite(11,0);
  }
  if(distance < 15 && distance >= 10){
    analogWrite(9,255);
    analogWrite(10,255);
    analogWrite(11,0);
  }
  if(distance < 20 && distance >=15){
    analogWrite(9,255);
    analogWrite(10,255);
    analogWrite(11,0);
  }
  if(distance >=25)
    analogWrite(11,0);
    analogWrite(10,255);
    analogWrite(9,0);
*/

  if(disctance)
}