accelerometer

The apple documentation for UIAcceleration class says, "When a device is laying still with its back on a horizontal surface, each acceleration event has approximately the following values: x: 0 y: 0 z: -1 " Now, I am confused! How can the acceleration be non-zero, when you clearly say the "device is laying still"? UPDATE Judging by the responses, I think this should be called something like 'forceometer' or 'gravitometer' and not accelerometer! You get a -1 on the Z axis because gravity is acting on the device, applying a constant acceleration of 1G. I assume you want user acceleration, which

i made my own application in Android that use compass and accelerometer sensors to display the degrees of rotation and inclination of my device. I initialized all the listener and objects i needed (i followed some tutorials), and now i can catch the degrees as i wished. The problem is that the measures that sensors return aren't accurate. I mean even if i try to round the values of degrees i catch from the sensor, they oscillate between -/+ 7 (or 8) degrees every fraction of a second, even if i stay in a grass field away from any disturbing source. What i want to have is a accurate measure of

To get orientation as a from of euler angles (e.g., pitch, roll, azimuth) in Android, it is required to execute followings: SensorManager.getRotationMatrix(float[] R, float[] I, float[] gravity, float[] geomagnetic); SensorManager.getOrientation(float[] R, float[] orientation); In the first one, I realize that it uses a kind of TRIAD algorithms; Rotation matrix (R[]) is composed of gravity, geomagnetic X gravity, gravity X (geomagnetic X gravity) --- X is cross product. See codes below: float Ax = gravity[0]; float Ay = gravity[1]; float Az = gravity[2]; final float Ex = geomagnetic[0]; final

Is there any application that is available which I can try out to see the difference between using an accelerometer and gyroscope (where the lag is evident while using an accelerometer). I get the theoretical aspect of using a gyroscope over an accelerometer. But I would like to see it visually. Ali Well, not an app but in this video , starting from 21:55, there is a demo. 来源： https://stackoverflow.com/questions/7383012/android-accelerometer-and-gyroscope

I am trying to work with 3D rotations but I don't seem to get the idea how the framework does the calculations. For example I get this data: yaw -1.010544 pitch 0.508249 roll 1.128918 Then I print the corresponding rotation matrix 0.599901 -0.128495 -0.789689 0.740043 0.464230 0.486649 0.304065 -0.876344 0.373584 After reading the API and the wiki, I am pretty sure there must be a general way to create a rotationmatrix out of euler angles. I tried all of these here , no results. Do I miss something, or how is this done? Well, iOS or CoreMotion provides both. RotationMatrix and Euler Angle

I am developing a game for Android (2.1+), using the accelerometer as user input. I use a sensor listener that I register at the beginning of the activity with the sensor manager, as follows: mSensorManager.registerListener(SystemRegistry.inputSystem.mSensorListener, accSensor, SensorManager.SENSOR_DELAY_UI); That works well and I just read the accelerometer values in onSensorChanged(SensorEvent event) in order to use it in my game loop: public void onSensorChanged(SensorEvent event){ accX = event.values[0]; accY = event.values[1]; accY = event.values[2]; } I am writing a real-time game so I