// The setup routine runs once when you load the sketch or press reset: // This is where you define pin directions void setup() { // initialize the pins used in this sketch pinMode(LED_BUILTIN, OUTPUT); // This LED Builtin in on pin 13 } // this "main" loop routine runs over and over again forever: void loop() { //Set pin 13 to HIGH. This provides 5 volts to the LED and turns it on digitalWrite(LED_BUILTIN, HIGH); delay(1000); //Wait for a second //Set pin 13 LOW and This turns the LED off digitalWrite(LED_BUILTIN, LOW); delay(1000); //Wait for a second }