I’ve previously had a “5 minute project” at Christmas time, where I made laser cut Christmas trees. The files are up on thingiverse so you can cut your own. This year’s is a more extravagant LED Christmas tree where the colour can be set by anyone via twitter.

Finished, in Green

As there was a string of WS2801 addressable LED lights that were available for me to experiment with in DoES Liverpool, I created a Christmas tree shaped spiral of lights that change colour depending on the current setting of the globally synchronised cheerlights API. When ever someone tweets cheerlights with a colour, all the light displays in the world that are listening will all change to that colour.

Just changing all the colours on the tree in a quick blink wasn’t really special enough, so I included an animation so when the cheerlights colour changes, the new colour displaces the old by spiralling up from the base to the top.

In testing, without star

Because it wasn’t quite looking like a Christmas tree with just a spiral of lights (in orange it looked like a traffic cone!), Adrian McEwen spent his “5 minutes” creating a star to go on top of the tree. 3D printed in clear PLA, the star is lit from within by the last LED in the strip. While the lights are changing, the star flashes through a sequence of colours and settles back to yellow when all of the lights have changed to the new colour.

Obviously this description is better with a video:

The code, cutfiles and 3D CAD files are all available on github.com/DoESLiverpool/Cheertree for you to copy, change or remix.

To change our’s (and everybody else’s) lights to a new colour, send a tweet that includes either:

• cheerlights

• @cheerlights

• cheerlights

with a colour from the following list:

• WarmWhite

• White

• Black

• Red

• Green

• Blue

• Cyan

• Yellow

• Magenta

• Orange

• Purple