void setup() {
  // put your setup code here, to run once:
  pinMode(11, OUTPUT);
  pinMode(10, OUTPUT);
  pinMode(9, OUTPUT);
}

void repeat(int pin){
  // put your main code here, to run repeatedly:
  for(int i = 0; i<=255; i+=5){
    analogWrite(pin, i);
    delay(30);
  }
  for(int i=255;i>=0; i -=5){
  analogWrite(pin, i);
  delay(30);
  }  
}
void loop(){
  repeat(11);
  repeat(10);
  repeat(9);
}