A typical Arduino microcontroller board is pretty small, about the size of a credit card. This makes it suitable for embedding into all sorts of electronic devices. But it's possible to go even ...

Just how small is the Micro? It measures in at 1.9-inches x 0.7-inches (48mm x 18mm). The board is based on the ATmega32u4, and has a built-in USB.

[Fabio Varesano’s] new Arduino compatible board packs a full power punch in a ultra compact layout, measuring at 20.7×15.2 mm, the Femtoduino is probably the smallest 328 based Arduino c… ...