For this instructable you will learn how to create a S.O.S singnal using a LED and arduino.
This project is perfect for bigginers (like me)
This is my first instructable and first arduino project so feel free to improve some stuff (like the programming) and correct me.

Step 1: Gather Your Parts

For this project you will need:
An Arduino (i have a duemilanove) Cost about 30 dollars
An LED (if you have the arduino that i have you can use the on board LED on pin 13) Cost about 2 dollars
A USB cable (for the arduino DUHHHH)

The tools that need are:
a Brain :) ,the most powerfull tool of all time

Step 2: Learn a Bit of Morse Code

First you need to learn a bit of Morse Code (to id the S and O)
-first of all a O reprents 3 long flashes
-secondly when you add a new letter thiere will be a 3 second delay
-thirdly a S is 3 short flashes

Step 3: Connecting Up Stuff and Uploading

Connect the usb to your arduino and cannect the led to pin 12 (13 if your using the on board led)
Than when your done that copy and paste the sketch
// This sketch will allow cause a led to do a SOS signal

int ledPin = 12; // LED connected to digital pin 12

// The setup() method runs once, when the sketch starts

void setup() {

pinMode(ledPin, OUTPUT);
}

void loop()
{
digitalWrite(ledPin, HIGH);
delay(1000);
digitalWrite(ledPin, LOW);
delay(3000);                // 3 second delay wich acts 1: before loop to make sure your ready and 2: act as a delay for when it starts all over again :)
digitalWrite(ledPin, HIGH);   //"S" signal starts after the one second delay
delay(1000);
digitalWrite(ledPin, LOW);
delay(500);
digitalWrite(ledPin, HIGH);
delay(1000);
digitalWrite(ledPin, LOW);
delay(500);
digitalWrite(ledPin, HIGH);
delay(1000);
digitalWrite(ledPin, LOW);
delay(3000);                  //3 second delay for the second letter (fisrt of 2)
digitalWrite(ledPin, HIGH);
delay(3000);                  // First dash of 3 wich represents the O
digitalWrite(ledPin, LOW);
delay(500);
digitalWrite(ledPin, HIGH);
delay(3000);
digitalWrite(ledPin, LOW);
delay(500);
digitalWrite(ledPin, HIGH);
delay(3000);
digitalWrite(ledPin, LOW);
delay(3000);                  //second 3 second delay for the third letter
digitalWrite(ledPin, HIGH);
delay(1000);
digitalWrite(ledPin, LOW);
delay(500);
digitalWrite(ledPin, HIGH);
delay(1000);
digitalWrite(ledPin, LOW);
delay(500);
digitalWrite(ledPin, HIGH);
}