Espresso for Geeks

From Espresso for Geeks:

Espresso for Geeks is a project to create a generic Open Source set of mods for semi-automatic espresso machines. These are the basic (but often high quality) machines that are composed of a single boiler, basic steam wand, vibratory pump, solenoid valve and a sometimes adjustable over-pressure valve (OPV). The mods described here are designed to enhance the features, performance and automation of these espresso machines. This project also aims to be a forum fostering a community of espresso geeks and makers where new techniques, ideas and theories are tested, developed, discussed and implemented. This is only possible when the code, schematics, enclosure designs and PCB designs are released under fully permissive Open Source licenses, so they are.

Read more, check out the code, and see more on Instructables