Original blog post: Femtoduino: designing an ultrasmall arduino compatible board with the ATMEGA 328P QFN/MLF32
As a personal learning exercise and challenge to myself, I designed an ultrasmall Arduino compatible board based on the ATMEGA 328P in the QFN/MLF32 package.
Using the smallest 328P uC currently available, very small package components (eg 0402 caps and resistors) and 0.05" headers I've been able to design an Arduino compatible board which is only 20.7x15.2 mm.
Given that the Arduino Pro Mini, currently the smallest Arduino board available, is 34x18 mm and I restricted myself to use a 2 side PCB, I think I accomplished a pretty good result.
I called this board Femtoduino. Have a look at the schematics. Of course this will be a free (as in speech) hardware.
I plan to submit this board to the DorkbotPDX group PCB order of the 3rd January and I'm currently looking for reviews and comments for the project. So, if you have knowledge of this topics please have a look at the Femtoduino designs.
You can get the Kicad sources (as of 30-12-2010) from here. I'm using a weekly updated version of Kicad, so if you have problems with older versions of Kicad you can try use a recent snapshot for Windows or Ubuntu 10.10.
You can get the most updated sources from my personal repository using bzr with the following command:
bzr co http://repository.varesano.net/Femtoduino
Thanks for your help!