Snow Flake Decoration

This is a short project documentation page for the snow flake project. 


The snow flake project is a winter decoration consisting of a number of snow flake boards connected to one single string of wire. Each snow flake contains an own micro controller and 19 bright and beautiful white LEDs.

Using very small and bright LEDs creates a unique and beautiful effect, like the sunlight sparkling in snow crystals.

Three snow flakes on a strand.

At the start, the individual snow flakes will communicate with each other and determine the own location in the strand. Next they display light patterns, which are synchronised between all boards.

Technically, the design is dead simple. The MCU is driving each LED individually with one GPIO. Each board has an input and output line for the bidirectional communication between the boards.

Build / Assembly

Soldering the snow flakes is quite difficult, because of the small size of the LEDs on the front side. Beside of this difficulty, everything else is very simple. Just add the LEDs, the MCU and resistors to the board – done.

There is a header on each board you can use to program the Atmel SAM D20 E15 micro controller. You will need a programmer, like the Segger J-Link to do this. 

If you order the boards, make sure to use a high quality board manufacturer (e.g. Eurocircuits). The fine lines and pads on the front only look nice if they are produced in a very precise way. 


You can find all files in the following GitHub repository:

The repository includes the following files:

  • Component List (BOM)
  • Board Design
    • Eagle files
    • Gerber files
  • Documentation how to build/connect the flakes.
  • Firmware binaries
  • Firmware source code.

Assembly Videos

Photo Gallery

The Fusion of Software and Hardware…

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