class Ui_MainWindow(object):
def setupUi(self, MainWindow):
    MainWindow.setObjectName("MainWindow")
    MainWindow.resize(800, 600)
    self.centralwidget = QtWidgets.QWidget(MainWindow)
    self.centralwidget.setObjectName("centralwidget")
    self.verticalLayout = QtWidgets.QVBoxLayout(self.centralwidget)
    self.verticalLayout.setObjectName("verticalLayout")
    self.label = QtWidgets.QLabel(self.centralwidget)
    self.label.setAlignment(QtCore.Qt.AlignCenter)
    self.label.setObjectName("label")
    self.verticalLayout.addWidget(self.label)
    self.dial = QtWidgets.QDial(self.centralwidget)
    self.dial.setObjectName("dial")
    self.verticalLayout.addWidget(self.dial)
    MainWindow.setCentralWidget(self.centralwidget)
    self.menubar = QtWidgets.QMenuBar(MainWindow)
    self.menubar.setGeometry(QtCore.QRect(0, 0, 800, 21))
    self.menubar.setObjectName("menubar")
    MainWindow.setMenuBar(self.menubar)
    self.statusbar = QtWidgets.QStatusBar(MainWindow)
    self.statusbar.setObjectName("statusbar")
    MainWindow.setStatusBar(self.statusbar)

    self.retranslateUi(MainWindow)
    self.dial.valueChanged['int'].connect(self.label.setNum)
    QtCore.QMetaObject.connectSlotsByName(MainWindow)

def ChangeSpeed(self):
        self.My_PWM.start(0)
        while True:
            if 0 < self.ui.label:
                self.My_PWM.ChangeDutyCycle(self.ui.label)
            elif self.ui.label<0:
                self.My_PWM.ChangeDutyCycle(0)
                print("Programme Ended")
                break