void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  pinMode(13, OUTPUT);
}

void loop() {
  digitalWrite(13, HIGH);
  Serial.println("led on");

  // put your main code here, to run repeatedly:
  delay(1000); // this speeds up the simulation
  digitalWrite(13, LOW);
  Serial.println("led off");
  delay(1000);
}