#define LED_PIN 2

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println("Hello World!");

  // Initialize the LED pin as an output
  pinMode(LED_PIN, OUTPUT);

  // Turn the LED ON by setting the pin HIGH
  digitalWrite(LED_PIN, HIGH);
}

void loop() {
  digitalWrite(LED_PIN, HIGH);
  delay(1000);
  digitalWrite(LED_PIN, LOW);
  delay(1000);   
}