/*

  Blink

  Turns on an LED on for one second, then off for one second, repeatedly.

  This example code is in the public domain.

 */

void setup() {                

  // initialize the digital pin as an output.

  // Pin 13 has an LED connected on most Arduino boards:

  pinMode(13, OUTPUT);     

}

void loop() {

  digitalWrite(13, HIGH);   // set the LED on

  delay(1000);              // wait for a second

  digitalWrite(13, LOW);    // set the LED off

  delay(1000);              // wait for a second

}