The Micro measures 48 mm in length and 18 mm in width and weighs about 13 g. The Nano, on the other hand, comes in the smallest form factor Arduino offers, with the same 18 mm width but a shorter ...

Based on the Arduino Pro Micro, this hand-wired pad is unique in that a single press of any of its 16 keys can virtually “type” out multiple lines of text.

The keyboard, which he is calling z.48, is based around the Arduino Pro Micro running a firmware generated on kbfirmware.com, and features some absolutely fantastic hand-wiring.