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Associate II
August 2, 2024
Solved

UART2 Status: Partly disabled conflict with PA mapped with GPIO_Output

  • August 2, 2024
  • 1 reply
  • 3125 views

Hi, a noob post from a noob developer. I am trying to understand how STM32Cube ide works. I guess by default UART2 has set as UART_TX - PA2, UART_RX - PA3. I have reconfigured PA1 and PA2 as GPIO_OutPut and set UART_TX - PA14 and UART_RX - PA15. There is a yellow warning sign beside UART2 that says, 'UART2 Partly disa bled conflict with PA mapped with GPIO_Output'

Below is the new configuration:
stm32cube_uart2_conflict.png

 

And below is the old configuration: 
stm32cube_uart2_conflict_old.png


In that case, can I continue to use the new configuration? 

Also planning to reconfigure the below pins: Will this be any problem? Do I have to configure RCC_OSC32_IN, RCC_OS32_OUT, RCC_OSC_IN, and RCC_OSCOUT? What do these use for?
stm32cube_uart2_conflict_3.png
Thank you in advance. 

Best answer by STTwo-32

If you are looking to activate the Hardware Flow Control (RS485), you have to set the PA1 to USART2 _DE. So, you can't use it as GPIO Output.

Best Regards.

STTwo-32 

1 reply

STTwo-32
Technical Moderator
August 2, 2024

Hello @Moza 

For the warning, means that you can't enable only the hardware flow control since it need to use the PA1 pin for an alternate function and not as GPIO Output. So if you want to use it you have to set PA1 as USART2_RTS. For the other Pins you mentionned on the third screenshot, they are used to connect external Clock source ( LSE and HSE). If you are not going to use them, you can disable them or configure them as gpio (for more details refer to the decreption inder table 13 of the https://www.st.com/resource/en/datasheet/stm32f091rc.pdf)

Best Regards.

STTwo-32 

MozaAuthor
Associate II
August 3, 2024

Hi, Thanks for your reply. So, does that mean I can not use PA1 as GPIO_Output?

STTwo-32
Technical Moderator
August 3, 2024

If you are looking to use the USART2 in a configuration that does not need PA1 (Asynchronous mode for example), you can use PA1 AS GPIO Output. But if you are going to use one of the modes that show a warning message that it will need PA1 to work, then you can't use PA1 as GPIO OUTPUT.

Best Regards.

STTwo-32