Arduino - Blinking LED

This is my first project with Arduino in instructables, but I create robots for few years with arduino.

The first I want I show you is The magic Hello World , that in electronics means Blinking LED!

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Step 1: What Do You Need :

  1. Arduino - I have a diferent versions but I wanna use Arduino Duemilanove and iDuno.
  2. Led Resistor - you can calculate but I generally use 220ohm.
  3. Wire.

Step 2: Parts & Schema

The protoboard I use to be more easy the wired.

Insert led check out how I put the led in the schematic is the position,
Connect the resistor to the led, and connect pin 13 on your arduino to a spot on yhe breadboard.

Step 3: Software

For this Arduino create some small tutorial programs that just you can download into the microcontrollers.

  1. open the Files
  2. go to the Sketch Book
  3. go to examples
  4. then to Digital
  5. and open 'Blink'

when you done with this go to the upload button above the screen and select it when its done you see the led starts to blink.

Step 4: Code

This is basically the code:

First create a variable call led with a value 13 that is the pin in the arduino.

With pinMode we put our variable in OUTPUT mode , that means that the pin of arduino is waiting for a signal to pass to the led.

In the loop we change the signal from high to low, that permite to us see the blink!!!

int led = 13;

void setup() {

pinMode(led, OUTPUT);


void loop() {

digitalWrite(led, HIGH);


digitalWrite(led, LOW);



Step 5: Videos

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    6 Discussions


    4 years ago on Introduction

    I have never worked with Arduino before. Am I right in assuming that the "delay(1000)" is the time in milliseconds that the LED is on or off? So on this example it's on 1 sec, then off 1 sec, repeat.. So on delay 25 you'd get exactly 20 pulses per second then.. (25 on, 25 off x 20 = 1000 milliseconds)

    Is the Arduino output strong enough to operate a relay switch?

    I'm thinking it could be useful for paintball markers - I have an old mechanical marker and upgrading it to electronic control is expensive. Looks like it could be DIY'd..

    Switch > Arduino > Relay switch > Solenoid trigger control..

    Should be possible to add an electronic safety, single shot, burstmode and full-auto as well..

    1 reply

    Reply 4 years ago

    Hi it's posible but you need add some circuits . I promise create a toturial use one of this to control something. And is a good idea for a paintball marker.


    4 years ago on Introduction

    Good start indeed. I like no nonsense instructables like this one. Specially when they come with a movie. (quite a bright green LED that your're using when looking at your movie).

    1 reply