之前一直能上传成功，现在不知道怎么了一直报错
无法打开端口“com 3”:file not found error
serial.serialutil.SerialException: could not open port 'COM3': FileNotFoundError(2, 'ϵͳ Ҳ ָ ļ ', None, 2)
serial.serialutil.SerialException: could not open port 'COM3': FileNotFoundError(2, 'ϵͳ Ҳ ָ ļ ', None, 2)
