They're just linear Hall Effect sensors. I don't see how they are supposed to tell direction. Would be easier to just use a gps that has a real electronic compass.

I think Gnuite + Andrew already answered the question, or maybe I am missing something, all OP needs to do, is to hold the GPS with the tablet together in one piece, turn on GPS>GPS info, and walked a few feet, that will give you the direction. That is what I have been doing when I want to find out. Anyway, its nice to see so many brains to attack a task of such a calibre, and BAC522 solution is the cutest of all


bun