Serial Speed change and USB issues on Win10

ChibiOS public support forum for topics related to the STMicroelectronics STM32 family of micro-controllers.

Moderators: barthess, RoccoMarco

Posts: 1
Joined: Fri Dec 21, 2018 10:07 am

Serial Speed change and USB issues on Win10

Postby PyB » Fri Dec 21, 2018 10:57 am


The below might be an awkward issue and not directly related to ChibiOS per say, but I'm posting to see if anyone experienced similar issues.

I have an application developed on top of a Nucleo Board (F446RE). This application uses the STM32 serial connected to STLink and accessible on a computer through a 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. I do this with sdStop and sdStart. This works fine on most computer I have used (win7, Win8, Linux, ...).

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 not really linked to ChibiOS...

Thanks for the help,

Return to “STM32 Support”

Who is online

Users browsing this forum: No registered users and 5 guests