Virtual port COM on STM32F756ZG visible but OTG_FS_IRQHandler appear all the time. So I can't communicate with my computer. Why?

[FToub.1]

I cannot communicate with my computer. I detect the port but in debug mode, I see that the OTG_FS_IRQHandler interrupt is triggered regulary when I send data on my computer.

I did the same thing with my dicsovery card F411, it works. But with nucleo F756, it doesn't work. I'll give you all the parameter I set in picture linked.

To complete, when I tried to open the COM port with python, I have this error :

serial.serialutil.SerialException: Cannot configure port, something went wrong. Original message: OSError(22, 'Paramètre incorrect.', None, 87)

Do you need more details?

Could you help me? I passed a lots of time on it and I don't find.

Thank you!

[Mike_ST]

Hello,

The fact that OTG_FS_IRQHandler is called is a good sign.

You have an example of VCP implementation in the F7 software package, so you can compare what is missing:

STM32Cube_FW_F7_V1.16.0\Projects\STM32756G_EVAL\Applications\USB_Device\CDC_Standalone

available here :

https://www.st.com/en/embedded-software/stm32cubef7.html

[FToub.1]

Thank you for your answer. I continue to search the response by comparing my code with this one

[FToub.1]

In fact, my program work well. It works well on windows 7 but not on windows 10, but normally, we don't need driver?

[Mike_ST]

You don't need it, normally.

But driver is here:

https://www.st.com/en/development-tools/stsw-stm32102.html

[FToub.1]

https://github.com/Ant1882/STM32F429-Tracealyzer-Demo/commit/4cf6591b3bdff098292349874f8c0c8df7802986