int redLED = 2;     
int yllwLED = 3; 
int redBrightness = 0; 
int yllwBrightness = 255; 
int fadeAmount = 200;     

void setup() {
  // put your setup code here, to run once:
  pinMode(redLED, OUTPUT);
  pinMode(yllwLED, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  analogWrite(redLED, redBrightness);
  redBrightness = redBrightness + fadeAmount;
  if (redBrightness <= 0 || redBrightness >= 255) {
    fadeAmount = -fadeAmount;
  }
  // Yellow LED berdenyut dengan fase yang berlawanan
  analogWrite(yllwLED, 255 - redBrightness);

  delay(100);
}