private void refreshChart() {
   // TODO Auto-generated method stub
   Float lightNum = collection.getLight();
   int index = mDataCache.addLightData(lightNum);
   if (index == 1) {
     mCurrentSeries.clear();
   }
   mCurrentSeries.add(index, lightNum);
   mChartView.repaint();
 }
 public void refreshDataView() {
   // TODO Auto-generated method stub
   Float lightNum = collection.getLight();
   mLightView.setText(lightNum.toString());
 }
 @Override
 public void onActivityCreated(Bundle savedInstanceState) {
   // TODO Auto-generated method stub
   super.onActivityCreated(savedInstanceState);
   collection = Collection.getCollection(getActivity());
 }