volatile uint8_t BRIGHTNESS_BUFFER[NUM_LEDS] = { 0 };
volatile uint8_t current_led = 0;
volatile uint8_t pwm_counter = 0;

ISR(TCA0_OVF_vect) {
  static uint32_t lastCheck = 0;
  static uint32_t lastCheck2 = 0;
  static uint8_t rot = 0;

  if (countDown(&lastCheck2, 10)) {
    BRIGHTNESS_BUFFER[28] = BREATH[rot++];
  }

  if (countDown(&lastCheck, 300)) {
    for (uint8_t led = 0; led < NUM_LEDS; ++led) {
      if (led == 28) {

      } else if (random8() & random8() & 1) {
        BRIGHTNESS_BUFFER[led] = random8() >> 3;
      } else {
        BRIGHTNESS_BUFFER[led] = 0;
      }
    }
  }

  TCA0.SINGLE.INTFLAGS = TCA_SINGLE_OVF_bm;  // Clear the interrupt flag
}

void loop() {

  resetLeds();
  if (pwm_counter < BRIGHTNESS_BUFFER[current_led]) {
    setLed(current_led);
  }
  delayMicroseconds(50);

  current_led++;
  if (current_led >= NUM_LEDS) {
    current_led = 0;
  }
  pwm_counter++;
}