Ux_Host-CDC_ACM : Enumeration failure

[LMore.2]

Dear All,

I am testing the demo project for the NUCLEO-C071 to implement the USB HOST CDC_ACM (USBX). Below are some doubts that arose after the initial tests:

1. After using the wizard to create the demo project 'Ux_Host-CDC_ACM', opening the .ioc file shows an error in the USBX configuration. In the 'Platform Settings' tab, the pin 'Drive VBUS_FS' is not defined. From what I understand, this should be the pin used by the library to enable the 5V power supply on the USB connector when in HOST mode. However, looking at the electrical schematic of the NUCLEO-C071, there is no pin available for this functionality! To supply 5V to the connector, there is the JP1 jumper (pin 7/8). The only way to avoid the error is to assign an unused pin! Isn't there a smarter way to avoid sacrificing a pin?

2. After resolving the error, without adding anything to the demo project, and having compiled and downloaded the program onto the NUCLEO board, any device I connect always results in the error "USB Device Enumeration failure." One of the device connected to the NUCLEO definitely implements a USB CDC. When connected to a Windows PC, it is correctly recognized, and I can work with it without issues using Teraterm. It is not a power supply problem; the board draws 200mA, and once connected, it seems to work correctly (LED and configuration via switch). However, it is simply not recognized by the NUCLEO.

Any suggestions?

Thanks.

[ABasi.2]

hello LMore.2

i have the exact same proble with a H5 board 

did you find a solution?

best reguards

[LMore.2]

Which of the two issues have you encountered as well? I imagine it's point 2.

After several emails with support, I discovered that some devices recognized as serial (COM) ports in Windows do not actually implement a CDC device but rather other types of USB interfaces. It is the dedicated Windows driver that makes it appear as a COM port.

I used two NUCLEO boards implementing both CDC-type HOST and DEVICE, and everything works perfectly. In my case, the device that I can't get STM32 to recognize is because it implements a USB COMPOSITE interface (Audio, CDC, HID).

What I was told is that, in the case of a COMPOSITE interface, the libraries must implement all the corresponding HOST interfaces for it to work. If this is indeed the case, I find it conceptually incorrect. I would expect that if the HOST only implements CDC and I connect a USB COMPOSITE device, the CDC connection would be established while the other interfaces would be ignored.

I haven't pursued this further because I wouldn't know how to implement a COMPOSITE interface.

[ABasi.2]

hello LMore.2 and thank you for your response!

yes the problem is the point 2, 

i'm trying to connect a super classic USB to RS232 device, i think its based on the most common chip used to do a USB to UART device.

in windows i see only a new com port when i plug in the device but when connected to my board (with a stm32H5) have the enumeration issue.

Another firmware where i setup a host MSC works perfectly so i don't think is an hardware issue

did yu know if i can check if the device i have is a real device CDC or is a different type of device?

 

thank you!

 

 

 

[LMore.2]

In the directory "C:\Program Files (x86)\Windows Kits\8.1\Debuggers", you will find the program "usbview.exe". I don't remember exactly, but I think it is installed with the "Windows SDK". In any case, refer to Microsoft's instructions: "https://community.st.com/t5/stm32-mcus-embedded-software/ux-host-cdc-acm-enumeration-failure/m-p/801086"

From what I’ve seen, devices that use chips for TTL/USB conversion (such as the FTDI232) are recognized by Windows as COM devices because the Windows driver handles this.

[ABasi.2]

thank you LMore.2

yes.it is a FTDI

so you are telling me that its ok that my board don't recognize ad FTDI because isn't a CDC device but another type of device and its windows via a specific driver that made the trick?

 

thank you!