const int pinLed = 13 ;

void setup (){
  Serial.begin(9600);
  pinMode (pinLed, OUTPUT);
  Serial.println ("Program sudah siap" );
} 

void loop (){
  digitalWrite (pinLed, HIGH);
  Serial.println("Led Nyala");
  delay (1000);
  digitalWrite (pinLed, LOW);
  Serial.println("Led Mati" );
  delay (1000);
} 

 

Source : Youtube Life Tech