USBx CDC ACM Dual Composite not working on STM32H723

[NRedd.2]

Hello all,

Following up on https://community.st.com/t5/stm32cubeide-mcus/usbx-dual-composite-cdc-acm-not-working/td-p/708277, I tried to implement the same Dual CDC-ACM on STM32H723 Nucleo. I have run into the same issues.

With just one CDC_ACM class registration, the example works well. But when two classes are registered, it is gibberish on the COM port (UART). 

uint8_t UserClassInstance[USBD_MAX_CLASS_INTERFACES] = {
    CLASS_TYPE_CDC_ACM,
    CLASS_TYPE_CDC_ACM
};

Similar to the previous post, I have modified ux_device_descriptors.c to correctly add the endpoints to the device framework string. With this change, I am able to see two ACM devices on Linux. 

[  +5.485446] usb 1-4.3.2: new full-speed USB device number 48 using xhci_hcd
[  +0.191080] usb 1-4.3.2: New USB device found, idVendor=0483, idProduct=5740, bcdDevice= 2.00
[  +0.000006] usb 1-4.3.2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[  +0.000002] usb 1-4.3.2: Product: STM32 Virtual ComPort
[  +0.000002] usb 1-4.3.2: Manufacturer: STMicroelectronics
[  +0.000001] usb 1-4.3.2: SerialNumber: CDC_ACM001
[  +0.015570] cdc_acm 1-4.3.2:1.0: ttyACM1: USB ACM device
[  +0.000352] cdc_acm 1-4.3.2:1.2: ttyACM2: USB ACM device

I have also increased FIFO sizes.

VOID USBX_APP_Device_Init(VOID)
{
  /* USER CODE BEGIN USB_Device_Init_PreTreatment_0 */

  /* USER CODE END USB_Device_Init_PreTreatment_0 */

  /* USB_OTG_HS init function */
  MX_USB_OTG_HS_PCD_Init();

  /* USER CODE BEGIN USB_Device_Init_PreTreatment_1 */

  /* Set Rx FIFO */
  HAL_PCDEx_SetRxFiFo(&hpcd_USB_OTG_HS, 0x200);

  /* Set Tx FIFO 0 */
  HAL_PCDEx_SetTxFiFo(&hpcd_USB_OTG_HS, 0, 0x40);

  /* Set Tx FIFO 2 */
  HAL_PCDEx_SetTxFiFo(&hpcd_USB_OTG_HS, 1, 0x40);

  /* Set Tx FIFO 3 */
  HAL_PCDEx_SetTxFiFo(&hpcd_USB_OTG_HS, 2, 0x40);
  /* USER CODE END USB_Device_Init_PreTreatment_1 */

  /* Initialize and link controller HAL driver */
  ux_dcd_stm32_initialize((ULONG)USB_OTG_HS, (ULONG)&hpcd_USB_OTG_HS);

  /* Start the USB device */
  HAL_PCD_Start(&hpcd_USB_OTG_HS);

  /* USER CODE BEGIN USB_Device_Init_PostTreatment */

  /* USER CODE END USB_Device_Init_PostTreatment */
}

Please find the GitHub repo here. 

Can someone from STM assist me please?

Best regards,

Navin

[FBL]

Hi @NRedd.2 

Have you tried the example provided? x-cube-azrtos-h7/Projects/NUCLEO-H723ZG/Applications/USBX/Ux_Device_CDC_ACM at main · STMicroelectronics/x-cube-azrtos-h7 (github.com)

[NRedd.2]

Hi @FBL,

Thank you for the response!

Yes, I have initially generated the code from STM32CubeMX based on the link you have suggested. Please find the repository here. 

And then, I tried to add another slave class, but I couldn't get it working.

With the initial example, I could communicate with ACM0 and ACM1 using terminal applications. 

After I added the ACM2 class, I can't even get the singe ACM to work (ACM1). Although, on Linux I see ACM devices listed.

Best regards,

Navin

[NRedd.2]

Hi @FBL ,

Have you looked into the issue yet?

[FBL]

Hi @NRedd.2 

I have an issue to flash your code on my end. To isolate the issue, I suggest you temporarily simplify the configuration by only adding the second CDC-ACM class and verifying if it works independently. This can help identify if the issue is with the second class or with the overall configuration

[NRedd.2]

Hi @FBL,

Thank you for the response!

As per your suggestion, I have isolated the ACM2 and pushed the code on GitHub. I think then the issue points to the overall configuration.

To isolate the second ACM:

• I commented out the enumerator so that I have only one CDC class.

  •  uint8_t UserClassInstance[USBD_MAX_CLASS_INTERFACES] = {
         CLASS_TYPE_CDC_ACM,
    -    CLASS_TYPE_CDC_ACM
    +    // CLASS_TYPE_CDC_ACM
     };

• Commented out the ACM1 device class registration and passed the ACM1's parameter to ACM2 for activation, deactivation and parameter change.

  • if (ux_device_stack_class_register("ACM2",
                                       ux_device_class_cdc_acm_entry,
                                       cdc_acm_configuration_number,
                                       cdc_acm_interface_number,
                                       &cdc_acm_parameter_1) != UX_SUCCESS)
    {
      /* USER CODE BEGIN USBX_DEVICE_CDC_ACM_REGISTER_ERORR */
      return UX_ERROR;
      /* USER CODE END USBX_DEVICE_CDC_ACM_REGISTER_ERORR */
    }

PS:

> I have an issue to flash your code on my end.

The project is configured for CMake. The only change I have made to compile is to append the compiler path 

set(TOOLCHAIN_PREFIX                /opt/gcc-arm-none-v12/bin/arm-none-eabi-)

to cmake/gcc-arm-none-eabi.cmake.

Best regards,

Navin

[FBL · Accepted solution]

Hi @NRedd.2 

Sorry for my late response. Your configuration is missing the initialization of the interfaces. You need to adjust CDC endpoint address for each CDC interface etc.. I suggest you follow this article to learn more about composite classes in USBX How to implement the USB device composite class in... - STMicroelectronics Community

[NRedd.2]

Hi @FBL 

I followed one of the blog posts and got it working. 

Seems like when UART is echoing, it doesn't work as expected.