OK、ようやくコードを機能させることができました!
まず、a Sensor.TYPE_MAGNETIC_FIELDandを登録しSensor.TYPE_GRAVITYます: (Hoan Nguyen が言ったように!)
/**
* Initialize the Sensors (Gravity and magnetic field, required as a compass
* sensor)
*/
private void initSensors() {
LocationManager locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
SensorManager sensorManager = (SensorManager) getSystemService(SENSOR_SERVICE);
Sensor mSensorGravity = sensorManager.getDefaultSensor(Sensor.TYPE_GRAVITY);
Sensor mSensorMagneticField = sensorManager
.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD);
/* Initialize the gravity sensor */
if (mSensorGravity != null) {
Log.i(TAG, "Gravity sensor available. (TYPE_GRAVITY)");
sensorManager.registerListener(mSensorEventListener,
mSensorGravity, SensorManager.SENSOR_DELAY_GAME);
} else {
Log.i(TAG, "Gravity sensor unavailable. (TYPE_GRAVITY)");
}
/* Initialize the magnetic field sensor */
if (mSensorMagneticField != null) {
Log.i(TAG, "Magnetic field sensor available. (TYPE_MAGNETIC_FIELD)");
sensorManager.registerListener(mSensorEventListener,
mSensorMagneticField, SensorManager.SENSOR_DELAY_GAME);
} else {
Log.i(TAG,
"Magnetic field sensor unavailable. (TYPE_MAGNETIC_FIELD)");
}
}
そして、私はそれSensorEventListnerを計算に使用します:
private SensorEventListener mSensorEventListener = new SensorEventListener() {
@Override
public void onAccuracyChanged(Sensor sensor, int accuracy) {
}
@Override
public void onSensorChanged(SensorEvent event) {
if (event.sensor.getType() == Sensor.TYPE_GRAVITY) {
mGravity = event.values.clone();
} else if (event.sensor.getType() == Sensor.TYPE_MAGNETIC_FIELD) {
mMagnetic = event.values.clone();
}
if (mGravity != null && mMagnetic != null) {
/* Create rotation Matrix */
float[] rotationMatrix = new float[9];
if (SensorManager.getRotationMatrix(rotationMatrix, null,
mGravity, mMagnetic)) {
/* Compensate device orientation */
// http://android-developers.blogspot.de/2010/09/one-screen-turn-deserves-another.html
float[] remappedRotationMatrix = new float[9];
switch (getWindowManager().getDefaultDisplay()
.getRotation()) {
case Surface.ROTATION_0:
SensorManager.remapCoordinateSystem(rotationMatrix,
SensorManager.AXIS_X, SensorManager.AXIS_Y,
remappedRotationMatrix);
break;
case Surface.ROTATION_90:
SensorManager.remapCoordinateSystem(rotationMatrix,
SensorManager.AXIS_Y,
SensorManager.AXIS_MINUS_X,
remappedRotationMatrix);
break;
case Surface.ROTATION_180:
SensorManager.remapCoordinateSystem(rotationMatrix,
SensorManager.AXIS_MINUS_X,
SensorManager.AXIS_MINUS_Y,
remappedRotationMatrix);
break;
case Surface.ROTATION_270:
SensorManager.remapCoordinateSystem(rotationMatrix,
SensorManager.AXIS_MINUS_Y,
SensorManager.AXIS_X, remappedRotationMatrix);
break;
}
/* Calculate Orientation */
float results[] = new float[3];
SensorManager.getOrientation(remappedRotationMatrix,
results);
/* Get measured value */
float current_measured_bearing = (float) (results[0] * 180 / Math.PI);
if (current_measured_bearing < 0) {
current_measured_bearing += 360;
}
/* Smooth values using a 'Low Pass Filter' */
current_measured_bearing = current_measured_bearing
+ SMOOTHING_FACTOR_COMPASS
* (current_measured_bearing - compass_last_measured_bearing);
/* Update normal output */
visual_compass_value.setText(String.valueOf(Math
.round(current_bearing))
+ getString(R.string.degrees));
/*
* Update variables for next use (Required for Low Pass
* Filter)
*/
compass_last_measured_bearing = current_measured_bearing;
}
}
}
};