addEntry

    private void addEntry() {

        LineData data = graph.getData();

        if (data != null) {

            ILineDataSet set = data.getDataSetByIndex(0);

            if (set == null) {
                set = createSet();
                data.addDataSet(set);
            }

            data.addEntry(new Entry(set.getEntryCount(), (float) (Math.random() * 40) + 30f), 0);
            data.notifyDataChanged();

            // let the graph know it's data has changed
            graph.notifyDataSetChanged();

            // limit the number of visible entries
            graph.setVisibleXRangeMaximum(120);
            // graph.setVisibleYRange(30, AxisDependency.LEFT);

            // move to the latest entry
            graph.moveViewToX(data.getEntryCount());

        }
    }