int ledPin = 13; // LED is connected to pin 13

void blinkLED(int delayTime) // we will send a delay time
{
  digitalWrite(ledPin, HIGH);  // turn LED on
  delay(delayTime);            // wait the specified amount of  time
  digitalWrite(ledPin, LOW);   // turn LED off
  delay(delayTime);            // wait the specified amount of  time

}

void setup() {
  pinMode(ledPin, OUTPUT); // set ledPin as an output

}

void loop() {

  blinkLED(500); // call the funtion and use a 500 millisecond delay time
  
}