Error while Music Test

[Tros-t]

Hello.

My code:

from lib.mBot import * from multiprocessing import freeze_support if __name__ == '__main__': freeze_support() bot = mBot() #bot.startWithSerial("/dev/ttyUSB0") bot.startWithSerial('COM3') tones ={"C3":131,"D3":147,"E3":165,"F3":175,"G3":196,"A3":220,"B3":247, "C4":262,"D4":294,"E4":330,"F4":349,"G4":392,"A4":440,"B4":494, "C5":523,"D5":587,"E5":659,"F5":698,"G5":784,"A5":880,"B5":988} music = ["E4","E4","F4","G4","G4","F4","E4","D4","C4","C4","D4","E4","E4","D4","D4"] while(1): try: for i in range(0,len(music)): bot.doBuzzer(tones[music[i]],500) sleep(0.5) except Exception: bot.doBuzzer(0) bot.doBuzzer(0) sleep(3)

The Error:

Exception in thread Thread-1: Traceback (most recent call last): File "C:\Python37\lib\threading.py", line 926, in _bootstrap_inner self.run() File "C:\Python37\lib\threading.py", line 870, in run self._target(*self._args, **self._kwargs) File "C:\Users\Ahmer Khan\Desktop\Arduino\python-for-mbot-master\lib\mBot.py", line 144, in __onRead r = ord(self.device.read()) File "C:\Users\Ahmer Khan\Desktop\Arduino\python-for-mbot-master\lib\mBot.py", line 45, in read return self.ser.read() File "C:\Python37\lib\site-packages\serial\serialwin32.py", line 285, in read ctypes.byref(self._overlapped_read)) TypeError: byref() argument must be a ctypes instance, not 'NoneType'

Help me pls