private void goCompass()
{
    Observable.create(new Observable.OnSubscribe<SensorEventListener>()
    {
        SensorEventListener listener = null;
        @Override
        public void call(final Subscriber<? super SensorEventListener> subscriber)
        {

            Sensor gsensor;
            Sensor msensor;
            final float[] mGravity = new float[3];
            final float[] mGeomagnetic = new float[3];



            listener = new SensorEventListener() {
                @Override
                public void onSensorChanged(SensorEvent event) {
                    final float alpha = 0.97f;
                    Float azimuth = 0f;

                    synchronized (this) {

                    if(switchChecked == false) {
                        subscriber.onNext(listener);
                        subscriber.onCompleted();
                    }

                    if (event.sensor.getType() == Sensor.TYPE_ACCELEROMETER) {

                        mGravity[0] = alpha * mGravity[0] + (1 - alpha)
                                * event.values[0];
                        mGravity[1] = alpha * mGravity[1] + (1 - alpha)
                                * event.values[1];
                        mGravity[2] = alpha * mGravity[2] + (1 - alpha)
                                * event.values[2];

                        // mGravity = event.values;

                        // Log.e(TAG, Float.toString(mGravity[0]));
                    }

                    if (event.sensor.getType() == Sensor.TYPE_MAGNETIC_FIELD) {
                        // mGeomagnetic = event.values;

                        mGeomagnetic[0] = alpha * mGeomagnetic[0] + (1 - alpha)
                                * event.values[0];
                        mGeomagnetic[1] = alpha * mGeomagnetic[1] + (1 - alpha)
                                * event.values[1];
                        mGeomagnetic[2] = alpha * mGeomagnetic[2] + (1 - alpha)
                                * event.values[2];
                        // Log.e(TAG, Float.toString(event.values[0]));

                    }

                    float R[] = new float[9];
                    float I[] = new float[9];
                    boolean success = SensorManager.getRotationMatrix(R, I, mGravity,
                            mGeomagnetic);
                    if (success) {
                        float orientation[] = new float[3];
                        SensorManager.getOrientation(R, orientation);

                        azimuth = (float) Math.toDegrees(orientation[0]); // orientation
                        azimuth = (azimuth + 360) % 360;

                        Log.d("obs", "azimuth (rad): " + azimuth);

                        layout.setRotation(azimuth);
                        imageView.setRotation(-azimuth);
                        contlayout.setRotation(azimuth);

                    }
                }
                }

                @Override
                public void onAccuracyChanged(Sensor sensor, int accuracy) {

                }

            };

            sensorManager = (SensorManager) getActivity()
                    .getSystemService(Context.SENSOR_SERVICE);
            gsensor = sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
            msensor = sensorManager.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD);

            sensorManager.registerListener(listener, gsensor,
                    SensorManager.SENSOR_DELAY_FASTEST);
            sensorManager.registerListener(listener, msensor,
                    SensorManager.SENSOR_DELAY_FASTEST);

        }
    }).observeOn(AndroidSchedulers.mainThread())
            .subscribe(new Subscriber<SensorEventListener>() {
                @Override
                public void onCompleted()
                {

                }

                @Override
                public void onError(Throwable e)
                {

                }

                @Override
                public void onNext(SensorEventListener listener)
                {
                    sensorManager.unregisterListener(listener);

                }
            });

}