title: get tilt angle Android
body: <p>I'm trying to get the tilt angle, roll angle from my sensors from my android phone but with no success so far,</p>
  
  <p>when I click on my button which should give me the 3 angles, I get "results: 0.0 -0.0 -0.0"   </p>
  
  <pre><code>package com.example;
  
  import android.app.Activity;
  import android.hardware.Sensor;
  import android.hardware.SensorEvent;
  import android.hardware.SensorEventListener;
  import android.hardware.SensorManager;
  import android.os.Bundle;
  import android.widget.TextView;
  import android.widget.Button;
  import android.view.View;
  
  
  public class MyActivity extends Activity
  {
      /** Called when the activity is first created. */
      @Override
      public void onCreate(Bundle savedInstanceState)
      {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.main);
          final float[] mValuesMagnet      = new float[3];
          final float[] mValuesAccel       = new float[3];
          final float[] mValuesOrientation = new float[3];
          final float[] mRotationMatrix    = new float[9];
  
          final Button btn_valider = (Button) findViewById(R.id.btn1);
          final TextView txt1 = (TextView) findViewById(R.id.textView1);
          final SensorEventListener mEventListener = new SensorEventListener() {
              public void onAccuracyChanged(Sensor sensor, int accuracy) {
              }
  
              public void onSensorChanged(SensorEvent event) {
                  // Handle the events for which we registered
                  switch (event.sensor.getType()) {
                      case Sensor.TYPE_ACCELEROMETER:
                          System.arraycopy(event.values, 0, mValuesAccel, 0, 3);
                          break;
  
                      case Sensor.TYPE_MAGNETIC_FIELD:
                          System.arraycopy(event.values, 0, mValuesMagnet, 0, 3);
                          break;
                  }
              };
          };
          btn_valider.setOnClickListener(new View.OnClickListener()
          {
              public void onClick(View view)
              {
                  SensorManager.getRotationMatrix(mRotationMatrix, null, mValuesAccel, mValuesMagnet);
                  SensorManager.getOrientation(mRotationMatrix, mValuesOrientation);
                  final CharSequence test;
                  test = "results: " + mValuesOrientation[0] +" "+mValuesOrientation[1]+ " "+ mValuesOrientation[2];
                  txt1.setText(test);
              }
          });
  
      }
  }
  </code></pre>