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!

i have find another post newer than the previous:

https://community.st.com/t5/stm32-mcus-embedded-software/how-can-i-communicate-with-my-host-mcu-via-usb-with-a-device-mcu/m-p/224337#M14488

according to that post the PROLIFIC class added to cube MX is for FTDI communications

i will give it a try!

[LMore.2]

I remember that at the beginning, when I thought that FTDI implemented the CDC class, I had tried using USBX, but it didn’t work. It’s likely that I also tried using the CDC protocol on the HOST. This is the first time I’ve heard of the PROLIFIC class, and I don’t think I’ve ever seen any code using it. It would be useful to have a demo code for this specific implementation. I don’t think I’d be able to create it from scratch. Especially now with the new USBX library. The old ones (USB_DEVICE and USB_HOST), although complicated, I could still manage to work with them. These new USBX libraries are extremely complex, I can’t make sense of them. At least, I can’t.

[ABasi.2]

Hi ,actually i 'm using only USBX , i have started my journey in the USB with USBX.

So i would give a try to the prolific class

Unfortunately there is no example for the prolific class today in the example selector of cube, there is an example for the CDC class that i have ported to my board

Now i give a try to the CDC HOST with a USBX device CDC made by myself and if i succeded i will try the HOST prolific class 

i will let you know

best reguards

[LMore.2]

Thanks! If you can do something with USBX, I'd be grateful. Let's join forces and see if we can conquer this USB! ;)