/*
  Simple traffic light
*/

const int LED_PINS[] = {18, 17, 16};

int count = 0;

void setup()  {
  for (int i = 0; i < 3; i++) {
    pinMode(LED_PINS[i], OUTPUT);
  }
}

void loop() {
  // turn all the LEDs off
  for (int i = 0; i < 3; i++) {
    digitalWrite(LED_PINS[i], LOW);
  }
  // turn LEDs on in sequence
  digitalWrite(LED_PINS[count], HIGH);
  count++;
  if (count == 3) count = 0;
  delay(2000);
}