// ESP32 Blink LED on D13, D12, D14, and D27

const int ledPins[] = {13, 12, 14, 27};
const int numLeds = sizeof(ledPins) / sizeof(ledPins[0]);

void setup() {
  for (int i = 0; i < numLeds; i++) {
    pinMode(ledPins[i], OUTPUT);
  }
}

void loop() {
  for (int i = 0; i < numLeds; i++) {
    digitalWrite(ledPins[i], HIGH);   // Turn the LED on (HIGH is the voltage level)
    delay(500);                       // Wait for a half second
    digitalWrite(ledPins[i], LOW);    // Turn the LED off by making the voltage LOW
    delay(500);                       // Wait for a half second
  }
}