Introduction: Music Synchronized LED Pumpkin

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This year, I decided to make my pumpkin a little more exciting.  I thought and thought about it, and then I came across LED Dance Room.  I figured "I could do that", and the project was born.

There are two modules for this setup: The Controller, and The LED/Breakout Board.  

The controller is simply an Arduino running software that allows a computer to control it over USB.

The breakout/LED board is a breadboard that has 12 ultra-bright leds connected to the digital pins on the Arduino over two 15 ft lengths of CAT5 cable.  The three unused wires in the cable are used to connect the speakers inside the pumpkin to the stereo that is near the controller.
The pumpkin is controlled by a processing script running on a computer.  This program detects the beats that the internal microphone in my laptop picks up. It then converts these to data that the arduino can read.  The arduino recives these signals and flashes different leds to different sounds (bass is brighter, treble is darker).  

Here is a video of it in action:

Step 1: What You Need...

 You will need...

For the controller
-An arduino
-a proto-shield(optional)

For the LED/Breakout board
-12 LEDs of various colours (the super-bright ones work best)
-a resistor (that matches your leds)
-2 speakers

You will also need a computer running the arduino software and processing.

Step 2: Installing Libraries

You will need to customize your processing install a little bit.  This is really simple and only takes a few minutes to do.

You will need to install two libraries: minim and the arduino library for processing.  You can get minim from  You will also need to install the arduino library, which can be found at 

Step 3: Building the Controller

The controller is the simplest part of this project. All you need to do is attach your wires to the output pins on your arduino.  Start by connecting wires to pins 2-13.  Then attach a wire to the GND pin on the arduino.  That's it.  I decided to make mine a bit better and soldered it to a prototype shield.  This is optional, but will make the finished product last longer.

Step 4: The LED/Breakout Board

This part is slightly harder, but still simple.  You now need to make up the LED array.  Start by placing all of your leds on the breadboard.  Connect all of their grounds together.  Now attach the wires that you connected to your arduino.  Finally, connect a resistor between your ground on the breadboard to the ground on the arduino.

I recommend that you wrap your electronics in plastic to prevent them from getting all gooey.

The schematic below should help.

Step 5: Programming

Now you need to program the arduino.  All you need to do is upload the "standard firmata".  To get this, go to file, then examples, then "Firmata", the click "StandardFirmata".  Upload this to your arduino board.  That's it.

Step 6: More Programming...

Now you need to load up your processing code.  I have attached it below.  All you have to do is export it, then run it.  That's all.  You can tweak and change it to mess with the flashing rates, but the ones there should work fine.

Step 7: Fire It Up!!!

Put your system into a carved pumpkin.  I chose to cave a drum kit into mine, but you can put anything on it.  You will have to cut a hole into the back of your pumpkin for the speakers to fit in. Once you do that, you can connect the speakers to your stereo, your arduino to your computer and your computer to your stereo.  Then run your code and play some music.  It should start flashing in sync with the music.  If it does not, you need to check that:

1. Your leds are connected correctly
2. You programmed the arduino correctly
3. You loaded the processing code correctly

If none of these work, please ask in the comments, or on the forum on my website (


Step 8: Final Thoughts and Possible Improvements

This project turned out really well.  The lights looked amazing and worked really well. If I were to improve this, I would build a better waterproof case for inside the pumpkin.  I would also solder the leds to a circuit board and use more LEDs.

If you have any ideas, please post them in the comments.

Thanks, and please remember to rate and vote if you enjoyed reading this.

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