// LED changing pattern: C


const int LED_PINS[] = {13,12,14,27} ;
const int NUM_LEDS = sizeof(LED_PINS)/sizeof(int) ; 
const int PWM_RESOLUTION = 8 ;
const int DUTY_MAX = 1 << (PWM_RESOLUTION) ;
const int PWM_FREQ = 5000 ;


#define OFF (LOW) 
#define ON (HIGH)


void setup() {
  // put your setup code here, to run once:
for (int i=0 ; i < NUM_LEDS ; i++){
  pinMode(LED_PINS[i], OUTPUT);
}
}

void loop() {
  // put your main code here, to run repeatedly:  
  int i=0 ;

  for (i ; i < NUM_LEDS ; i++) {
    ledcSetup(i,PWM_FREQ,PWM_RESOLUTION) ;
    ledcAttachPin(LED_PINS[i],i) ;
      for (int x=0 ; x < DUTY_MAX ; x++){
        ledcWrite(i,x);
        delay(10);

  }
  }
  for (i-- ; i >= 0 ; i--){
    ledcSetup(i,PWM_FREQ,PWM_RESOLUTION) ;
    ledcAttachPin(LED_PINS[i],i) ;
      for (int x=DUTY_MAX ; x >= 0 ; x--){
        ledcWrite(i,x);
        delay(10);


  }
  }
  delay(1000);
}