It is mind-boggling when you think about the computing power that fits in the palm of your hand these days. It wasn’t long ago when air-conditioned rooms with raised floors hosted computers far less powerful that filled the whole area. Miniaturization is certainly the order of the day. Things are getting smaller every day, too. We were so impressed with the minuscule entries from the first “Square Inch Project” — a contest challenging designers to use 1 inch² of PCB or less — that we decided bring it back with the Return of the Square Inch Project. The rules really were simple: build something with a PCB that was a square inch.

via Packing a Lot Into a Little PCB: Winners of the Square Inch Project — Hackaday