Mass storage device mode (USB OTG) of STM32H7 not recognized in some computers

[TVare.1]

Hello everyone,

I have a device based on a STM32H753ii which has an USB-OTG interface that is used for both serial communication and for mass storage mode. This last one is to have access to an EEPROM that is also on the same PCB.

Normally, if we build in "debug" mode, the USB can be connected to the computer and we can see the logs in the terminal through a COM port. Then, we have a command which will terminate this serial communication and mount a mass storage device. Normally, in any computer we see how the serial communication is terminated and some seconds later a new mass storage device is mounted and recognized.

I know that in general there might be hardware or USB library implementations issues in the device. My problem is that in many computers (both with Windows 10 and Linux) it works normal as expected; which makes me believe that I have a local issue in my PC.

In my computer (Windows 10) it is not even recognized as a mass storage device. I suspect that is some problem related to my drivers, but not sure how to solve it. I have tried by uninstalling all the USB drivers through the device manager, and still no luck.

Any ideas?

Thank you!

[Pavel A.]

Try to plug it thru a USB 2.0 hub (not 3.x), better a powered one. If this helps, the problem can be electrical (marginal power or distortion of DP/DM signals).

[TVare.1]

Hi, thanks for the answer. I couldn't find an USB 2.0 hub, but I tried with a powered 3.0 one and still have the problem. I tend to believe that the problem is not electric (at least not mainly) since a colleague of mine has exactly my same computer model and it works just fine there.

[TVare.1]

Just as an update, I couldn't solve it nicely. I had to clean my computer and re-install windows from scratch in order to make it work.