void setup() {
  pinMode(2, OUTPUT);
  pinMode(3, OUTPUT);
  pinMode(4, OUTPUT);
}

void loop() {
  
  int nilai;
  for (int nilai = 0; nilai < 255; nilai++) {
    analogWrite(2, nilai);
    delay(5); 
  } 

  for (int nilai = 0; nilai < 255; nilai++) {
    analogWrite(3, nilai);
    delay(5); 
  } 

  for (int nilai = 0; nilai < 255; nilai++) {
    analogWrite(4, nilai);
    delay(5); 
  } 

  if (nilai == 255)
  {
    nilai = 0;
  }
}