Hello Emilio! That's a great idea, nice work! I'm part of a group trying to build one and ... well, the documentation is rather scarce. (More over here: http://forum.openag.media.mit.edu/t/community-documentation/842/6). Before building, we are trying to make some kind of summary of the project, what is it doing, what are the parts doing (and hopefully why were they chosen), what's the function of the software (really no clue on this), and so on. All of this in order to make better design decisions and to buy sensors and actuators that do the right thing (for money and availability reasons, we cannot buy all the original things).
A question for @gordonb or @Caleb or whoever is responsible. May we write some wiki articles in Spanish? With an [ES] tag or something, of course. Else we can write over here maybe, with an [ES] tag also.
@Santi and @frandagostino are also Spanish speakers and could give us a hand. (PS: I'm also in Argentina!)