USB composite device – HID + CDC ACM example on Linux

[Lubos KOUDELKA]

Hello,

when using Linux host for testing this example, CDC interface is not detected by the host. Reason is sensitivity on Configuration descriptor content generated by STM32CubeMX, propagated into ux_device_descriptors.c. For now you fix this file manually if you want to verify example functionality with Linux host in ux_device_descriptors.c (~line 806)

 /* Control interface headers */
  pHeadDesc = ((USBD_CDCHeaderFuncDescTypedef *)((uint32_t)pConf + *Sze));
  /* Header Functional Descriptor*/
  pHeadDesc->bLength = 0x05;
  pHeadDesc->bDescriptorType = 0x24;
  pHeadDesc->bDescriptorSubtype = 0x01;  //originally 0x00
  pHeadDesc->bcdCDC = 0x0001;  //originally 0x1001
  *Sze += (uint32_t)sizeof(USBD_CDCHeaderFuncDescTypedef);

Fix shall be propagated into future version of STM32CubeMX.

[FHars]

Thanks, that works.

The only thing that might be confusing for the unwary is that the Enter key may (depending on the terminal program one uses) only send a CR (Ctrl-M), if one wants the output to move to the next line, one has to explicitly send a LF (Ctrl-J) in that case.