Blossom

Blossom is my attempt at an Open Source Board designed using KiCad 6 and OpenSCAD. It packs 12 LEDs driven by a technique called Charlieplexing and 3 Buttons which are read using one analog pin. The board itself resembles a flower, at its heart an ATtiny85 MCU.

The firmware for the board can be found in the blossom-firmware repository.

Have a look at the interactive BOM here.

The KiCad Project

The project related files are placed in kicad/. The aim of the project was to learn a lot and besides that create a small PCB controlled by an ATtiny85 which blinks some LEDs and reads in input from three buttons.

The 12 LEDs are controlled by just 4 pins using Charlieplexing. The current states of the 3 buttons is sampled by charging a capacitor depending on which button is pressed and reading the analog input.

The board outline

You can find the files used to create the board outline and various positions for holes and the position of the LEDs under cad/.

To open the files you need to install OpenSCAD.

Custom silkscreen icons

Using a tool called svg2mod I was able to convert a SVG icon drawn in Inkscape to a KiCad footprint module file. You can find the files in icons/.

You can easily do this with this command:

svg2mod -i blossom.svg -o blossom.kicad_mod -p 0.1

where p stands for precision, the smaller the more precise.

The finished PCB

(This is the 1.0 version)