led que parpadea.jpg
Ejercicio 1: Blinkin LED (LED que parpadea)

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

Most Arduinos have an on-board LED you can control. On the Uno and
Leonardo, it is attached to digital pin 13. If you're unsure what
pin the on-board LED is connected to on your Arduino model, check
the documentation at http://www.arduino.cc

This example code is in the public domain.

modified 8 May 2014
by Scott Fitzgerald

the setup function runs once when you press reset or power the board
void setup() {
initialize digital pin 13 as an output.
pinMode(13, OUTPUT);

the loop function runs over and over again forever
void loop() {
digitalWrite(13, HIGH);
turn the LED on (HIGH is the voltage level)
delay(1000); wait for a second
digitalWrite(13, LOW);
turn the LED off by making the voltage LOW
delay(1000); // wait for a second