Make a Mini LED Siren (powered by Arduino!)

This is one of the first projects I have made with Arduino. It's a little siren with a LED that fades and blinks on and off. It demonstrates basic use of LEDs and speakers. Also check out this article: 8-Pin Programming Shield

Constructive criticism is appreciated!

Let's get started!

Step 1: Materials & Tools

Fist off, gather your materials and tools. I am assuming that you known the basics of Arduino and how to solder.

Materials:
-Arduino Uno
-USB cable for the Arduino (sometimes called a printer cable)
-solderless breadboard
-breadboard jumper wires
-LED (Any color)
-A small resistor or two.
-small speaker (I found one for $2 at a thrift store)
-Ping pong ball

Tools:
-soldering iron
-electrical solder
-pliers

Step 2: Solder Jumper Wires to the Button and Speaker

Fire up your soldering iron and attach wires to each of leads on the button and the speaker. The picture shows mine when I was done.

Step 3: Drill a Hole in the Table Tennis Ball

Grab your dremel and drill a hole in the bottom of the ping pong ball. Make it large enough for the LED bulb to fit inside.

Step 4: Wiring It Up

Get power to the breadboard:
Run a jumper wire from the Arduino GND pin to a breadboard "-" row.
Run a jumper wire from the Arduino 3.3v pin to a breadboard "+" row.

Wire the button:
Run one of the buttons wires to anywhere on the breadboard's "+" row.
Run the other wire to an empty column on the breadboard.
Run a resistor from the button wire column to an empty column.
Run a wire from the resistor column to Arduino pin 7.

Wire the LED:
Stick the LED on to the breadboard. Slide each pin into a different column.
Run a wire from the positive LED column to Arduino pin 5.
Run a wire from the negative LED column to breadboard "-" row.

Wire the speaker:
Run one of the speaker wires to breadboard "-" row.
Run the other wire to Arduino pin 3.

Slide the ping pong ball over top of the LED. (not pictured)
Just slip it over the LED.

Hopefully the pictures will help make sense of what I'm saying.

Step 5: Programming the Arduino

Now we have to program the Arduino to make the LED flash and the Speaker well... speak! I have written a sketch (thats what Arduino programs are called) for us already. Download the file, open it in the Arduino software, then upload it to the board. (But first, connect the Arduino to your computer with the USB cable.) I Won't explain how to set up the Arduino software on you computer because there are many articles out there that describe it better than I can. Such as this one .

Step 6: Finished!

Hooray! now we get to test it! If all went well (and my instructable was accurate), the siren and ping pong ball light should spring into action at the press of the button! As you can see from the picture, I made a crude button holder by poking a hole in the top of a disposable cup. I also cut a notch in the side to let the wires out.