void setup() {
  // put your setup code here, to run once:
  // initialize digital pin LED_BUILTIN as an output
  pinMode(LED_BUILTIN, OUTPUT);

}

void loop() {
  // put your main code here, to run repeatedly:
  digitalWrite(LED_BUILTIN, HIGH); // turn LED on (HIGH voltage level)
  delay(1000);	// wait for a second
  digitalWrite(LED_BUILTIN, LOW);	// turn LED off (making voltage LOW)
  delay(1000);

}