Coffee Appreciation

I really like the Arduino coffee machine idea from jacob. My machine is definitely in need of something like that. How much time did you spend? how difficult was it to get sensors?

Thanks. I did use some time learning to program the micro processor, say to hours a day for tree month. But until now I have only been doing the very basic stuff and I'm far from finishing the system. I didn't use any new sensors, I'm only interfacing with things that are present in the standard machine (3-way valve, steam boiler filling valves and the flow-meter). My gear-pump/motor unit are the only special thing in my system.
For more info: http://www.home-barista.com/espresso-machines/pressure-profiling-with-fluid-o-tech-tmfr-pump-or-wholesale-copying-greg-scaces-ideas-t12179.html.