2020-09-04 03:02 AM
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.
2020-09-05 02:34 PM
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