[mikets]

I did not follow the entire thread of discussion so if I misunderstood the issue, I apologize. But I do want to mention my experience on dealing with the accelerometer by integrating it twice to get distance. How did you differentiate the distance value to get speed? In particular, how did you get dt? The reason I ask is because I discovered that if you have code that is supposed to be run periodically at a fixed interval, don't count on the interval being accurate. For example, my integrator code is supposed to run every 10 msec, eventually I found out that it got called every 20+ msec instead. So don't use the period as your dt because it is not accurate. Your speed data will be all over the place. I scratched my head on the accelerometer for a while until I finally timed the interval of my code being called and found that I can't depend on it being constant. So I now wrote the code to measure the interval and use it as my dt instead. Then my integrator is now quite accurate.