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How to overwrite the generated USB descriptors in usbd_cdc.c

Katzenberger.Michael
Associate III

Hi !

I'm using the USB CDC IP as simple USB to serial converter but I don't want to implement the needed CDC functionalities.

Under Linux this leads to a blocking of the virtual com port /dev/ttyACMx for several seconds due to the modem manager tries to interact with my "non-modem" TTY device.

Don't know if this is really the right way to do but setting the descriptor value for

/* bInterfaceProtocol: Common AT commands */

from 0x01 to 0x00 "solves" this issue (e.g. https://github.com/solokeys/solo/issues/62#issuecomment-474178352)

Therefore I'm looking for a way to overwrite the generated USB descriptors in Middlewares/ST/STM32_USB_Device_Library/Class/CDC/Src/usbd_cdc.c

Best regards,

Michael.

1 REPLY 1
Pavel A.
Evangelist III

Please look at descriptors of any "dumb" serial to USB adapter such as Prolific, Silicon Labs. They work well and don't have anything AT.

-- pa