I'm using stm32 Workbench with CubeMX and STM32F4DISCOVERY with STM32F407VG microcontroller
I setup everything in CubeMX as default:
- RCC-> Crystal/Ceramic Resonator
- SYS->SerialWire with SysTic Timebase Source
- USB_OTG_FS-> Device_only
- In MiddleWares, USB_DEVICE-> Communication Device Class (VCP)
- I setup Clock Configuration with input frequency 8 MHz HSE and 168MHz HLCK
- In Configuration: USB_OTH_FS Configuration i disable Vbus sensering
- In USB_DEVICE Configuration is setup as default
Everything compile without any problems and errors.
When I connect my stm to PC, microcontroller log as COM port.
I send messages to PC with CDC_Transmit_FS function.
I receive messages on PC with HTerm program.
HTerm show this COM port normally.
When I try click connect button in HTerm, program don't connect with COM port and shows error:"Error in OpenPort: Internal error when initializing COM4".
But in some situations (sometimes when I rebulid code, but not often), I can connect with this port and I can receive messages from stm- but not every time.
When connect with this com port and I click connect and disconect buttons several times COM port has an error describe above.
This problem shows up when I using Windows 10 Pro system, but when I use Windows 7 Proffesional system this problem problem never occurred