2023-04-26 02:00 PM - edited 2023-11-20 07:03 AM
Currently using Nucleo-H7A3ZI-Q to test the USB FS interface and using Cube FW 1.10.1 -
Using Nucleo end as USB Device mode with CDC class.
I followed the AN4879 documentation to understand more on this topic of vbus sensing and it looks like vbus sensing is mandatory when self powered which in the case of nucleo board - yes its self powered but it seems like turning on the vbus sensing without the external 5V supply is not making the USB work at all. Does the term "self powered" mean setting nucelo as USB Host ? or does it mean self powered internally to turn on the USB transceiver (VDD50USB ON and VDD33USB ON) to bypass the internal USB regulator?
It almost looks like if vbus sensing is enabled, then it expects the external 5V from USB Host, otherwise the USB transceiver is shut off even though the VDD50USB and VDD33USB are powered internally and hard tied to 3.3 net as per schematics.
Is this the intended behavior of the Cube FW enabling this bit in this setup ?
2023-09-25 12:11 PM
Did you get any a reply from ST staff regarding this issue?
There seems to be a lack of clear data on the USB front at the moment.