Jason @ Hackszine writes -

Here’s the latest espressotronic creation in the long human tradition of modifying machines to produce the perfect cup of coffee. The creator, Nash Lincoln, got a few of his ideas from a similar project which used a PIC and an NES controller to manage a Rancilio Sylvia machine. Between the two of these projects, you should have enough inspiration and technical knowhow to start hacking your way toward your own espresso nirvana.

Ardiuno-controlled Gaggia espresso machine – Link.