User USB (CN13) of NUCLEO-F446ZE not recognized when stocking on NUCLEO-IHM07M1

[apexyz]

I encountered a weird problem when configuring user USB (CN13) of NUCLEO-F446ZE as a virtual COM port. If no other board (e.g., NUCLEO-IHM07M1) is stocked on, this USB can be recognized as a COM port in Windows 10. However, once NUCLEO-IHM07M1 is mounted, immediately the following message pops up. Any idea about the reasons? How to fix such an issue? 

 

[Peter BENSCH]

Welcome @apexyz, to the community!

Well, if you take a look at the schematics of the NUCLEO (MB1137), you will see that CN13 is the connector for the User USB port and PA9 (USB_VBUS), PA10 (USB_ID), PA11 (USB_DM) and PA12 (USB_DP) are used for this purpose, which are led out at CN12.21, CN12.33, CN12.14 and CN12.12.

If you take another look at the schematics of the X-NUCLEO-IHM07M1 (tab CAD Resources), you will discover that these pins lead via CN10 to the signals IN2, IN3, DIAG/EN and CPOUT.

If you plug an X-NUCLEO into a NUCLEO, you must therefore always check carefully whether the functions required by the X-NUCLEO are still free to use on the NUCLEO.

Hope that answers your question?

Good luck!
/Peter