How to measure the tilt of the phone in XY plane using accelerometer in Android

by

Essentially, there is 2 cases here: the device is laying flat and not flat. Flat here means the angle between the surface of the device screen and the world xy plane (I call it the inclination) is less than 25 degree or larger than 155 degree. Think of the phone lying flat or tilt up just a little bit from a table.

First you need to normalize the accelerometer vector.
That is if g is the vector returns by the accelerometer sensor event values. In code 

float[] g = new float[3]; 
g = event.values.clone();

double norm_Of_g = Math.sqrt(g[0] * g[0] + g[1] * g[1] + g[2] * g[2]);

// Normalize the accelerometer vector
g[0] = g[0] / norm_Of_g
g[1] = g[1] / norm_Of_g
g[2] = g[2] / norm_Of_g

Then the inclination can be calculated as 

int inclination = (int) Math.round(Math.toDegrees(Math.acos(g[2])));

Thus 

if (inclination < 25 || inclination > 155)
{
    // device is flat
}
else
{
    // device is not flat
}

For the case of laying flat, you have to use a compass to see how much the device is rotating from the starting position.

For the case of not flat, the rotation (tilt) is calculated as follow

int rotation = (int) Math.round(Math.toDegrees(Math.atan2(g[0], g[1])));

Now rotation = 0 means the device is in normal position. That is portrait without any tilt for most phone and probably landscape for tablet. So if you hold a phone as in your picture above and start rotating, the rotation will change and when the phone is in landscape the rotation will be 90 or -90 depends on the direction of rotation.

More Related Contents:

  1. How to refresh app upon shaking the device?
  2. Android accelerometer accuracy (Inertial navigation)
  3. Strange behavior with android orientation sensor
  4. Indoor Positioning System based on Gyroscope and Accelerometer
  5. How to use Accelerometer to measure distance for Android Application Development
  6. Android TYPE_LINEAR_ACCELERATION sensor – what does it show?
  7. How can i simulate accelerometer in android emulator? [closed]
  8. Android accelerometer not working when screen is turned off
  9. Filtering accelerometer data noise
  10. How do I use the Android Accelerometer?
  11. What is the real world accuracy of phone accelerometers when used for positioning?
  12. how to calculate phone’s movement in the vertical direction from rest?
  13. Moving an image using Accelerometer of android
  14. Transforming accelerometer’s data from device’s coordinates to real world coordinates
  15. Is there a way to retrieve multiple sensor data in Android
  16. Acceleration from device’s coordinate system into absolute coordinate system
  17. Picasso v/s Imageloader v/s Fresco vs Glide vs Coil [closed]
  18. Android Gradle plugin 0.7.0: “duplicate files during packaging of APK”
  19. Change application’s starting activity
  20. Usage of forceLayout(), requestLayout() and invalidate()
  21. Show GIF file with Glide (image loading and caching library)
  22. How to detect power connected state?
  23. Why use armeabi-v7a code over armeabi code?
  24. Google Geocoder service is unavaliable (Coordinates to address)
  25. Add gradient to imageview
  26. filling a circle gradually from bottom to top android
  27. “Calling this from your main thread can lead to deadlock and/or ANRs while getting accesToken” from GoogleAuthUtil(Google Plus integration in Android)
  28. How to use notifyDataSetChanged() in thread
  29. Android Emulator: This app won’t run without Google Play services
  30. Java.lang.ClassNotFoundException after Android studio update

Leave a Comment