2018-12-21 02:04 AM
Hello,
I have an application developed on top of a Nucleo Board (F446RE). This application uses the STM32 serial lines connected to the STLink MCU and accessible on a computer through an USB VCP.
The F446RE Uart is initially set @ 921kbps and is working fine. While the application is running, I sometime need to change the UART speed to 115kbps or even 9.6kbps.
This works fine on most computer I have used (win7, Win8, Linux, ...), I mean on the computer when i change the terminal (TeraTerm speed, I can see communication works well).
Lately I stumbled upon a strange issue with a couple of Win10 PCs:
- Win 10 PC use the Microsoft Win10 USB VCP driver
- On one PC when I change the speed from 921k to 9.6k it works, but when i change from 921k to 115k it doesn't (the PC still sees the VCP but no data exchange is possible).
- On the other PC when I change the speed (whatever speed) the VCP either disappear (rarely) or the VCP doesnt work anymore (no more data seen)
- Tests were done with a simple term software (TeraTerm)
Any clue where it can come from, it is pretty annoying and probably link to either the STLink firmware (I use latest) or the Win10 driver - or a combination of both.
Thanks for the help,
PyB