#define LED_RED_PIN     D10
#define LED_GREEN_PIN   D9
#define LED_BLUE_PIN    D8

uint8_t SegPin[] = {
  LED_RED_PIN, LED_GREEN_PIN, LED_BLUE_PIN
};

hw_timer_t *timer = NULL;

void IRAM_ATTR onTimer() {
  static boolean blueOut = LOW;
  digitalWrite(LED_BLUE_PIN, blueOut);
  blueOut = (blueOut == HIGH)? LOW : HIGH; 
}

void task(void *pvParameters){
  static boolean greenOut = HIGH;
  while (true) {
    digitalWrite(LED_GREEN_PIN, greenOut);
    greenOut = (greenOut == HIGH)? LOW : HIGH; 
    delay(500);
  }
}

void setup() {
  for (uint8_t i = 0; i < sizeof(SegPin); i++) {
    digitalWrite(SegPin[i], LOW);
    pinMode(SegPin[i], OUTPUT);
  }
  timer = timerBegin(1000000);
  timerAttachInterrupt(timer, &onTimer);
  timerAlarm(timer, 1000000 / 4, true, 0);
  timerStart(timer);
  xTaskCreateUniversal(task, "task", 4096, NULL, 1, NULL, 0);
}

void loop() {
  static boolean redOut = HIGH;
  while (true) {
    digitalWrite(LED_RED_PIN, redOut);
    redOut = (redOut == HIGH)? LOW : HIGH; 
    delay(1000);
  }
}