Ever want to have a fancy, programmable Christmas tree? Look no more! It's so easy I'll just give out a recipe on how to do your own. I started this project yesterday when I went to the dollar store and I found battery-powered Christmas lights.


You'll need:

• Battery-powered lights (about $1, mine have 10 lights and is powered with 2 batteries)
• A tree (also about $1 for the not-actually-a-tree-but-a-garland-on-a-plastic-frame variety, mine's about a feet high, perfect for your desk)
• An Arduino or any MCU lying around with its USB cable (around $25-30). Any programmable board that have at least a PWM pin and a ground pin will do, I used a TI C2000 launchpad, but using an Arduino might be easier to program.
• Wire and/or an IDE cable (You should have those lying around if you did some electronics before. Else you should find that at the hardware store.)
• No batteries! (around $0)

1. Decorate your tree with your lights. (Optional? Or else it won't be a tree otherwise.)

2. Plug the + side of the battery pack to a pin that supports PWM on your microcontroller and the - side to the ground. (An IDE cable might be handful if you don't want to solder and the pins on the controller are male, unlike the Arduino.)

3. Load up a PWM example on your microcontroller, compile and upload it. Be sure the PWM pin it uses is the same as the one you plugged the tree in. You can send a number between 0 and 255 to that pin, 0 being 0% intensity and 255 is 100% intensity. (In my example, it's a fade in/out example.)

And there we go, a pretty christmas tree.

Now what else should I do with that?

• Use a button to switch between patterns
• Control the intensity via the serial port
• Change the intensity according to the music

The sky is the limit! Any other suggestions? I should try those ideas out in the holiday time. (Yeah there's no pics of the steps, I'll might add some later.)

I completely forgot about the yearly christmas hack! I should build this to make up for it!

Funny how benryves did exactly the same thing.

You mean IDE cables? Those are great. They have a lot of smaller wires in them which are single core. This is super easy to solder and you can put a lot of them in a tiny space. I use them for all of my projects now!

How... what... why...

nice christmas tree, eeerm, nice blinking LEDs

I thought about it a bit. I have a kit with a PIC microcontroller and 4 PWM output. If I wire my christmas lights accordingly, I could make patterns with the different colors. *Leaves to get a christmas lights kit, a solder iron and some duct tape*

I don't think you'll be able to play anything.