I'm creating Suwako Moriya's hat for Närcon 2015 and decided to make the eyes interactive.
Using an Arduino Uno and 2 NeoPixel 8x8 LED matrix inside spheres, different eyes and animations will be projected onto the surface of the sphere (from the inside).
I decided to release the code if it's useful for anyone else and will release guides on how to create the hat itself (if I manage to do it).
As two NeoPixel matrices are being used, following libraries are required:
Disclaimer: I am not a C programmer, code may or may not follow proper C coding practices