Okay, so I've been looking at something like this to control a fermentation chamber, and this seems as good a place as any to ask about it.
I'm building a keezer/fermentation cabinet based off Mylo's design
. What I'm thinking is 3 separate fermentation chambers in the top, with enough room for 2 carboys in each (I may eventually go to 10 gallon batches, and I figure I can split them into 2 carboys and ferment side-by-side. Also allows room for experimentation.)
So I'm just gonna be running fans for temp control, they'll pipe up cool air to cool the chamber, and then I was going to put in removable, insulated dividers, because I'll probably just stick a brew belt on the carboys to keep them from getting too cold (and really, that'll be down the road a little bit, because I'm not lagering or anything). Onto the part that's actually relevant to this thread: I'm debating between a FermTroller (which is already programmed and just needs to be installed and have temp probes attached) or doing it with an Arduino. I'm not sure which way to go.
I know you said the BrewTrollers were pretty high quality, Mylo, but I'm thinking I may eventually want to set it up to be controlled via the web, and Arduino offers a few more options on that front. There's an ethernet controller for the FermTroller, which also might work, but the firmware doesn't support it yet and I don't know anything about coding at this point in time (this is part of the reason I'm thinking of just going with the FermTroller anyways.). Down the road I might want to upgrade each carboy to have independent-ish temp control as well, so I'd need support for 6 different zones (6 inputs and 6 outputs). So I dunno which way to go.
Honestly, the more I write, the more it seems like the Fermtroller is probably the more logical choice, but I figured I would let some of the experts weigh in.