Simple Blinking LED (External)

int led = 13; // set the "led" variable as 13
 
void setup() {                
  pinMode(led, OUTPUT);   // designate port 13 as output
}
 
void loop() {
  digitalWrite(led, HIGH);   // turn the led on
  delay(1000);               // wait for 1 second
  digitalWrite(led, LOW);    // turn the led off
  delay(1000);               // wait for a second
}