def create_knob(self):
        knob = Qwt.QwtKnob(self)
        knob.setRange(0, 180, 0, 1)
        knob.setScaleMaxMajor(10)
        knob.setKnobWidth(50)
        knob.setValue(10)
        return knob
    #---------------------------------------------------
Purpose:   create a knob
dataset/ETHPy150Open mba7/SerialPort-RealTime-Data-Plotter/live_monitor.py/PlottingDataMonitor.create_knob