German electrical engineering student Tobias Lauxtermann has taken a Raspberry Pi, an Arduino MEGA and several other boards and bits and pieces and created a set of Christmas decorations that are controllable over the Internet. The Pi runs a Node.JS server which receives the commands and then sends them to the Arduino. There is feedback from the Arduino to the Pi to tell the Pi when it’s ready to receive data. There’s even a Telegram text service which you can use to send text to a dot matrix display. The video of the decorations is live-streamed onto YouTube. You can have a go at controlling a train, a Christmas tree full of LEDs and also, of course, a dancing Christmas tree. Visit the UI to the project here and read more about how the project was accomplished here.