Tiniest possible arduino

Tiniest possible arduino
« on: July 12, 2018, 10:31:07 AM »
Recently I've discovered this design for a 0.4" x 0.4" arduino compatible board:

My proposal:
  • a similarily sized Tinyduino, possibly powered by a small battery cell
  • a neopixel addon board which can be soldered to the bottom side of the board (using spacers)