“The goal of our implementation was to make the machine useable in both standalone and Internet connected modes. This means breaking into the push buttons and interfacing with the status LED. However the PCB within the machine floats at MAINS voltages. This is a potentially dangerous situation therefore one of the prime interfacing tasks is to create a totally electrically isolated inteface. We achieve this using opto isolators. Just before boxing the machine up, we made some final interfacing tests. The most important test is isolation where we checked that the optoisolators were indeed correctly connected and that there would be no electrical connection between the WebBrick and the coffee machine.”
My co-worker and I (both computer technicians) made one of these three or four months ago.
The design was not as clean. We used a CD-ROM tray’s PCB, and wired the eject button to the power button on the coffee maker. Using one of the small exhaust port holes to trail the wires out of, we had the computer sitting beside the coffee-maker, and could use the Windows “Right-Click -> Eject” feature over a remote desktop connection to power on the pot.
We turned it on one night at my apartment, went to work and then had some coffee already made. IT pwnt. Sitting in the back room now though, buried underneath a bunch of other little frankensteins ..