I am starting a new project that will require the person that wants a coffee to twitt about something in order to get a coffee made by brewno (the spresso machine).
It consist of bypassing all the electronic control it originally had with the spark. Right now I am controlling the boiler and pump with solid state relay’s… I am learning about Triacs to replace them so that I can put everything in a neat board 
I have one of my servers monitoring twitter and when it detects a hashtag it hits the spark cloud to request a function call to starts the brew. Each brew consists of several operations… Opening the machine using servos (still working on the mechanics). Drops a coffee capsule and closes the machine… And then start’s the boiler and brew and pump…
Right now I am working on the PID to control de boiler. And looking for a way to measure fluid flow… Because the original flow meter is attached to the original Neapresso PCB and seems difficult to interface without the PCB because the Hall effect sensor is attached to the board. Looking for alternatives here. I tried another flow meter but it was slightly larger and the pump couldn’t drive it.
Any ideas or comments welcomed. I am going to post code and boardin github when donee… Neapresso seems simplistic enough to hack.
PS: if anyone knows a source of a good simple SSR design tutorial (To drive 120VAC 60hz for the pump and Boiler 60W) that I can implement directly in the PCB… WOULD be awesome!!