def dcLeft(self, port): ser = serial.Serial(port, baudrate=9600, timeout=1500) ser.write(struct.pack('>B', 4)) ser.close() def dcRight(self, port): ser = serial.Serial(port, baudrate=9600, timeout=1500) ser.write(struct.pack('>B', 5)) ser.close() def steppLeft(self, port): ser = serial.Serial(port, baudrate=9600, timeout=1500) ser.write(struct.pack('>B', 6)) ser.close() def steppRight(self, port): ser = serial.Serial(port, baudrate=9600, timeout=1500) ser.write(struct.pack('>B', 7)) ser.close() class Window(App): def build(self): return MyWidget() if __name__ == "__main__": window = Window() window.run()