STM32H7 USB CDC - without VBUS pin?

[Rahu2710]

I am using the STM32H743ZIT6 MCU to enable USB CDC. In my schematic, I have not defined the VBUS pin; I have only defined the CDC lines. Can I still use CDC without the VBUS pin? Below is the photo of my schematic for reference. Please help me.

Thank you for your assistance.

[TDK]

> Can I still use CDC without the VBUS pin?

Yes. You are not required to connect VBUS to use USB.

The USB standard does require that you check VBUS before energizing the data lines, but you can typically safely ignore that. If your device is USB powered, there is no need to check.

Schematic looks good.

[Rahu2710]

Thank you for providing the solution.

[anupam1511]

i used this configuration setup in ioc file and call the cdc transmit function in main.c but not working out , is this happening because of VBUS missing as mentioned above by rahu2710 , he is from hardware team , and i am from software team .

please help me .

[TDK]

> "not working out"

This is not a useful description of a problem. What behavior do you see? What behavior are you expecting? Have you done any debugging?

Consider working from a known good example, or using that as a base.

STM32CubeH7/Projects/STM32H743I-EVAL/Applications/USB_Device/CDC_Standalone/Src/main.c at 662d95d4bc2a03d5c3647e673e3edec218507e5b · STMicroelectronics/STM32CubeH7