“Possibly the smallest ATtiny85 based ‘duino derivative”. Indeed! When Olimex announced the Olimexino 85s as the smallest Arduino ever, [Tim] took that as a challenge. His very small Arduino based USB ...

[Frank Zhao] put together a USB business card. It’s even got the instructions printed right on the silk screen of the PCB explaining how it should be used. He based the design around an AVR ATtiny85 ...