STM32F411CE USB CDC BlackPill

LPrat.3 · ‎2021-09-25

I have a blackpill board with STM32F411 48 pins IC and CubeMX/CubeIDE at lastest versions. The USB is configured as device CDC, no Vbus.

When I flash the board with generated code and plug USB in Windows 10 I get an error "invalid device descriptor". I have increased heap to 0x1000 without success.

It not seems a hardware issue because I can enter the board in DFU and flash or erase device using CubeProgrammer.

Any help will be apreciated.

Leonardo

LPrat.3 · ‎2021-09-26

I found the solution, I have to increase the heap (0x1000), but this isn't enough to solve. I need to change the automatic clock configs of CubeMX that use internal 16MHz clock as source to core.

The image bellow show the way that works.

View solution in original post

Pavel A. · ‎2021-09-25

> It not seems a hardware issue

Then there's an invalid device descriptor. Check with a bus analyzer.

LPrat.3 · ‎2021-09-26

But the automatic code generated by CubeMX isn't reliable?

LPrat.3 · ‎2021-09-26

I found the solution, I have to increase the heap (0x1000), but this isn't enough to solve. I need to change the automatic clock configs of CubeMX that use internal 16MHz clock as source to core.

The image bellow show the way that works.