3 Compass(es) or 3D Compass?

[Chris Hyde]

I'll talk to you guys during the Saturday meeting (tomorrow) but I was just working on a little android project, and my phone has a 3D compass(as opposed to 3 compasses which are averaged, which basically measures earths magnetic force in XYZ directions.  Using this and the accelerator, the phone puts these values through some magic equation that we could look up in some physics book and pops out fairly accurate orientation values which would be VERY useful for AI.  These values are (azimuth, pitch, roll) where azimuth is "yaw" from true north.

Check this picture for clarity. just imagine the phone is a submarine.-

SO: can we make this happen, or are our magnetic field sensors not for this purpose? or something else?

[Cameron Evans]

If our compass and accelerometer are super accurate, we can actually use the data for stabilization. If it is crappy, we can really only use the sensors to tell what our general orientation is and that our motors are actually making us move. It's worth making the data super accurate.