No CDC ACM/COM port is being formed for USB Device code for STM32U5G-DK1

[Sudarshan]

Hello,

I am making a new project by importing the .ioc file of example code "Ux_Device_CDC_ACM" of STM32U5G-DK2. All the .c files of USB_stack and Azure_RTOS are also copied from the example project. Both, example project and My project, look same. My project builds also successfully. But no COM/ACM port is being formed after loading the project to STM32U5G-DK1 whereas, COMM port is being formed with Example project. 

What can be the reason ? Please help.

NOTE: USB Device mode Example project in repository is provided for STM32U5G-DK2 and not for DK1. So. we are trying to make a USB Device code by referring to this DK2 example.

With regard,

Sudarshan Chaudhary

[FBL]

Hi @Sudarshan 

I suggest performing a thorough debug to check errors during execution. Additionally, I noticed that the VDD core voltage differs in the schematics; please ensure that the power supply and related hardware implementation are correctly configured.

[Sudarshan]

USB ACM port is being formed now in my created project for USB CDC.

But as soon as we enable USART3 in this project and call HAL_UART_Receive_IT() for USART3 on DK1 board in "main.c" file, just before "MX_ThreadX_Init()" ,  formed ACM port disappears and we are no longer able to send any data to DK1 board over USB. We have tried this with different USART3 NVIC priorities.

I need to enable this USART3 for another thread.  If I comment HAL_UART_Receive_IT() from main.c and calls it inside the my UART related thread then ACM port forms but data transmission over USB gets stuck. I am unable to debug how and why USART3 is interfering with USB of STM32U5G9NJ-DK1.

This above behaviour persists even with the "Ux_Device_CDC_ACM" example code of STM32U5G-DK2 board.

Attached herewith is the screenshot of NVIC priorities in my program.