Christmas Tree

Elimo Engineering 2021 Christmas Tree

The tree’s main construction is a 2-layer, 1mm thick circuit board. The entire design had to be made using the normal circuit board manufacturing techniques but still look presentable, for example some of the ‘baubles’ on the front are made using silkscreen, others have the soldermask removed to expose the (rather pleasing) gold plated finish.

The front side has 18 APA102 (similar to WS2812B) addressable RGB LEDs, and on the back you’ll find an ATTiny167 8-bit microcontroller, USB-C connector, and two buttons – RESET and MODE. By default the tree will run the FastLED library demo reel program and cycle through some patterns – the MODE button isn’t implemented in the demo (an exercise for the reader perhaps  ).

  • Dimensions (HxWxD): 100mm x 84mm x 7mm
  • Power: 5V @ 500mA (USB Type C)
  • LEDs: APA102-2020-256-6 (Datasheet)
  • Microcontroller: ATTiny167 (Datasheet)
  • Schematics: (PDF)
  • Gerbers: (Zip)
  • Demo Arduino sketch: (.ino sketch)