There is UART BUG on STM32F446RCT6

[Mugtaba]

STM32CUBEIDE:  version 1.14.1
PA0-WKUP ------> UART4_TX
PA1 ------> UART4_RX

On a new project when enabling the UART4 with interrupt on receive ,everything is working normal .
But once I enable PH1 pin as a GPIO_OUTPUT the UART is not transmitting or receiving any more.

Any ideas or help please?

Update 1: I attached the two code form comparing.
Update 2: if I configure the PH1 pin as input the UART4 will work normal

[STOne-32]

Dear @Mugtaba ,

PH0 and PH1 are used by the HSE - High speed crystal oscillator for precise clock and get right UART baudrate , if PH1 is configured as GPIO , the system will run on internal HSI and your  UART baudrate will be lost and so stopping at application level . Can you check your clocks ?

Cheers,

STOne-32

[Mugtaba]

Thank you for your reply
but the HSE is already disabled, I am using the internal clocks

[STOne-32]

Interesting ! And what is your UART4 baudrate ? We need to replicated such behavior never seen before .

Cheers,

STOne-32

[Mugtaba]

I tested it starting from 9600, 115200 to 512000

[Mugtaba · Accepted solution]

I have solved the problem by my self, I had to enable the printf and scanf as I have used them as UART transmission function from the project settings (didn't know why it is working once the PH1 pin is disabled)
also I added this line before the while (1) __HAL_UART_ENABLE_IT(&huart4,UART_IT_RXNE);

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@Mugtaba wrote:

STM32CUBEIDE:  version 1.14.1
PA0-WKUP ------> UART4_TX
PA1 ------> UART4_RX

On a new project when enabling the UART4 with interrupt on receive ,everything is working normal .
But once I enable PH1 pin as a GPIO_OUTPUT the UART is not transmitting or receiving any more.

---

For the PH1 pin still don't know I am leaving it for the STM team

[STOne-32]

Dear @Mugtaba ,

glad to see you solved the problem observed . however this is weird to have a link between printf / scanf and PH1 GPIO activation ! To fully understand the root cause :  sharing the full project and settings are helpful.

Cheers,

STOne-32

[Mugtaba]

Thank you for your reply
I did share (on the question it self as attachment) the two project when the PH1 is enabled and disabled.