I got a 5-meter reel of individually-controllable RBG LEDs for my birthday this year. Their light is gorgeous, especially the super-saturated blues and greens. But other than stringing them up around the office I haven’t done much with them. Christmas LED project time!
And this one couldn’t be easier. Get yourself down to your local big box store (Kmart, Walmart – whichever is having a 40% Christmas decorations sale) and pickup one of those small-size spiral lighted Christmas trees that stand a little under 4-ft high when they’re expanded. I paid $12 for this one one sale.
Next, take your 5-meter strip of RGB LPD8806 LED lights, plus a 5V/10A dc power supply and a power connector from Adafruit. The 5m reel will set you back about $150, which is a very good deal for a quality digitally programmable light strip. (Although the light strip is encased in a waterproof tube, this setup is appropriate for indoor use only.)
Solder the power connector to a shield proto board for an Arduino and connect it to the female wiring receptacle for the light strip. (I got a separate one from Adafruit, or, you can cut it off the opposite end of the 5m light strip – you’ll use the male connector end to plug the strip in.) Wire it up according to the excellent 8806 tutorial here, which also has links to a nice light display sketch for the Arduino, which is the one you’ll see in the video below.
You don’t absolutely have to use a proto shield for the wiring connections; You could just wire the power plug directly into the light strip wiring along with the data and clock signals. But a shield makes things a little more accessible.
Now’s a good time to plug the strip into the wire receptacle, download the lighting sketch to the arduino, and fire it up to test the strip. If you don’t know anything about Arduinos, start with Adafruit’s intro tutorial and then go on to the 8806 tutorial.
Now assemble the spiral tree by putting together the vertical tube sections that serve as the tree support, sticking them into the base, pulling up the center of the spiral, and attaching the star at the end of the spiral to the star at the top of the tube.
NOTE: See all those incandescent (ie, Watt-sucking) white christmas lights along the spiral? Ignore them. You won’t even plug them in; They just serve as a base to balance the strip on.
Which is the next thing you do: Take the strip and. Starting at the bottom, wind it along the spiral up to the top of the tree. It comes out fairly even.
You’ve already tested out the sketch on the light strip, so you know everything is running fine – now turn it on and enjoy your extremely bright, gaudy Christmas tree light show.
I saw a project for the TI TMS430 Launchpad which uses the crazily inexpensive Launchpad board ($4.30) as the controller in place of the Arduino – the software is here on Github.
The Launchpad folks have noticed that what people really love about the Arduino is the great dev environment, so the Launchpad community recently ported over the Arduino IDE to Launchpad. My next project will be to crank up a 430 Launchpad to control the lights.