def __init__(self, **kwargs):
super().__init__(**kwargs)
btn = Button(text="press 10", pos=(G.xpos[0] - 15, G.btn_y))
btn.size = (80, 50)
btn.pin_no = 10
btn.bind(on_press=self.on_event)
self.add_widget(btn)
btn = Button(text="press 20", pos=(G.xpos[1] - 15, G.btn_y))
btn.size = (80, 50)
btn.pin_no = 20
btn.bind(on_press=self.on_event)
self.add_widget(btn)
Clock.schedule_interval(self.update, 0.05) # 1.0/50.0) 1/50 sec interval
