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Associate III
March 16, 2025
Solved

USB_OTG_FS and USART1 Async on same board

  • March 16, 2025
  • 1 reply
  • 745 views

Hi! I'm using an STM32F401RET6 and was planning on using both USART1 in Asynchronous mode and USB_OTG_FS peripherals.

In STM32CubeIDE when they are configured at the same time there is an error. I've tried PA9/10 and PB6/7 for TX/RX for USART1 but the same warning/error shows. 

I wonder if there is some pin configuration interference that it isn't showing or if maybe some interference with the boot modes (Section 3.12 of DS9716).

Can I use USART1 and and USB_OTG_FS at the same time?

jlaufer_0-1742146271064.png

 

Best answer by STTwo-32

Yes, it is just impossible to configure the  Hardware Flow Control (RS232) since it will need an additional pin that is already used for USB_OTG_FS. That’s why we have the warning sign next to USART1 and red sign on the Hardware Flow Control (RS232) configuration menu.

Best Regards.

STTwo-32

1 reply

STTwo-32
Technical Moderator
March 16, 2025

Hello @jlaufer 

What I see is that you are able to use Both USART1 and USB_OTG_FS on your .ioc file without problems. Could you please tell me what is the problem you are having on your configuration.

Best Regards.

STTwo-32

jlauferAuthor
Associate III
March 16, 2025

@STTwo-32 Thanks for the response. I'm concerned about the yellow warning sign next to USART1 and the red highlighted "Hardware Flow Control (RS232)". Does this just mean I can't use in the Hardware Flow Control feature?

STTwo-32
STTwo-32Best answer
Technical Moderator
March 16, 2025

Yes, it is just impossible to configure the  Hardware Flow Control (RS232) since it will need an additional pin that is already used for USB_OTG_FS. That’s why we have the warning sign next to USART1 and red sign on the Hardware Flow Control (RS232) configuration menu.

Best Regards.

STTwo-32