Angle measurement for balancing robot.

[Archangel]

joe - this was my first reaction also. but then i read this N&V article... they put the batteries in the 'head'

I will take the time to read that article again.
JS
Edit:
The article says they moved the batteries up to "increase the inertia", I see that as an attempt to cause the accelerometers to respond faster. Their robot chassis is made of whiteboard, probably the reason they needed to increase the inertia, as that cardboard is not very stiff, I believe they could have achieved similar results by moving the accelerometers up to the "Head"
where nature put ours. Anyway those are my thoughts on the matter, It's up to you to sort out whats good and what's useless.
Have fun,
JS