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Can't Enumerate Telit modem USB port as a CDC ACM device with usbx host

Bfuller
Associate II

     I am using an STM32 Nucleo H563ZI board for stm32CubeIDE and I am trying to send AT commands to a Telit LE910C4-WWX threadx modem over usb using the usbx host and threadx middleware. My program should be able to detect the modem as a cdc acm device, but it's failing to enumerate. When I connect a usb mouse to the Nucleo, it can enumerate properly as an hid mouse, which leads me to believe that the modem might not be properly configured. When I connect the modem with the configuration AT#USBCFG=1, it steps through the _ux_host_class_cdc_acm_entry() function 7 times, and the last time, it is able to check for IAD presence, but the IAD class is 2, and the IAD subclass is 0, so it still fails. Is there some other configuration for the modem I need to do, or do I need to modify the usbx driver or the ioc file?

21 REPLIES 21

I am happy to hear that you solved your problem and thank you for sharing the solution with us. So you defined the data interface class code as vendor specific class and it works fine in cdc? What about the communication, subclass and protocol? have you also changed them? 

It is now fully functional. All I had to do was change the data class, nothing else. I do need to have the modem in a specific usb composition though. It just needs the 2 modems as well as the ecm interface. It can't have the diagnostics interface.