Thanks for the reply Eric,
I suspected that issue with heading and pitch/roll may need some software calibrating to be presentable in a way that makes sense to the orientation of the rover. Just couldn't find any other users describing the same problem, which I find odd since this would be a general problem with all IMU/depth modules.
I'm more concerned with the dead data on IMU. Will do some more troubleshooting, though I'm more into electronics than programming. Appreciate it if you find some more info on the problem.
Just one thing, the MPU-9150 contains a 3-axis electronic compass: AK8975, which works on Hall sensor technology. Apparently this requires calibration prior to operation.
"A Hall probe can be used to measure the Earth's magnetic field. It must be held so that the Earth's field lines are passing directly through it. It is then rotated quickly so the field lines pass through the sensor in the opposite direction. The change in the flux density reading is double the Earth's magnetic flux density. A Hall probe must first be calibrated against a known value of magnetic field strength"
I'm not sure if this is done at factory prior to shipping, or needs to be done by consumer, I would assume this is done at factory. At least it is done in diving computers, all though it is possible for users to perform another calibration. Anyway, I'm sure you guys have thought of it, just checking in case.
Still , I love the concept of the IMU, felt like an F-15 fighter pilot whilst waiving the ROV'er around. And it should really prove to be helpful navigating, specially mid-water without visual reference, something I know a bit about being a diver myself.
I see there are discussions on the forum on how to apply the IMU in navigation, found a good video on Youtube that illustrates the potential: http://www.youtube.com/watch?v=6ijArKE8vKU
Although I'm unsure how easy it is to program this within the boundaries of existing software architecture.
Anyway, time for a beer, Saturday night and all :-) (nearly 10:00 PM in Norway now)