Code to blink a LED on Arduino.

led-blinking.ino

/**
 * Code to blink a LED
 *
 * Author:  Kadu NovoK
 * Date:    12-09-2013
 * Version: 1.0
 */

void setup() {
    pinMode(13, OUTPUT);    // Set the LED
}

void loop() {
    digitalWrite(13, HIGH); // Turn on
    delay(1000);            // Wait a second

    digitalWrite(13, LOW);  // Turn off
    delay(1000);            // Wait a second

    digitalWrite(13, HIGH); // Turn on
    delay(100);             // Wait 100 miliseconds

    digitalWrite(13, LOW);  // Turn off
    delay(100);             // Wait 100 miliseconds

    digitalWrite(13, HIGH); // Turn on
    delay(100);             // Wait 100 miliseconds

    digitalWrite(13, LOW);  // Turn off
    delay(100);             // Wait 100 miliseconds
}