When the device is not flat, you have to call remapCoordinateSystem(inR, AXIS_X, AXIS_Z, outR); before calling getOrientation. The azimuth returns by getOrientation is obtained by orthogonally project the device unit Y axis into the world East-North plane and then calculate the angle between the resulting projection vector and the North axis. Now we normally think … Read more
If you integrate the acceleration twice you get position but the error is horrible. It is useless in practice. Here is an explanation why (Google Tech Talk) at 23:20. I highly recommend this video. Now, you do not need anything accurate and that is a different story. The linear acceleration is available after sensor fusion, … Read more
TL;DR, see the code and picture at the bottom. I think a Kalman filter could work quite well in your application, but it will require a little more thinking about the dynamics/physics of the kite. I would strongly recommend reading this webpage. I have no connection to, or knowledge of the author, but I spent … Read more
Basically, it is a problem with my phone. Other users have reported this also happens with their phones, from different brands but same Android version. Other persons have no problem at all – strongly indicating that this is not a problem with the stock version of android but from the implementations of each company for … Read more
A stationary device will have an gravity value of +9.81, which corresponds to the acceleration of the device (0 m/s2 minus the force of gravity, which is -9.81 m/s2). Thus if the device is moving downward from stationary then the gravity will be less than 9.81. A free fall device will have gravity equals 0. … Read more
Very interesting question!!!! I’m developing somethig similar to your application. What i found about TYPE_LINEAR_ACCELERATION isn’t happy for me. 1) TYPE_LINEAR_ACCELERATION, TYPE_GRAVITY, ecc are implemented only for Android 2.3 (and up) So i have Android 2.2 and i can’t test them. 2) TYPE_LINEAR_ACCELERATION isn’t so accurate as it would be, because there are some simple … Read more
In my comment on the checked answer on the link you provided above, I referred to my simple answer at calculate acceleration in reference to true north Let me answer here again with more clarification. The answer is the product of the rotation matrix and the magnetic field values. If you read further on the … Read more
This is a common problem with yaw, pitch and roll. You cannot get rid of it as long as you are using yaw, pitch and roll (Euler angles). This video explains why. I use rotation matrices instead of Euler angles in my motion sensing application. For an introduction to rotation matrices I recommend: Direction Cosine … Read more