Change the Alternate functions default pin for USART1 on STM32F103

[JLEE.61]

Hi,

I want to change TX/PB6 to RX/PB6 for USART1 on STM32F103.

Please let me know if you have a solution.

Thanks.

[Tesla DeLorean]

Remap the I2C1 off the PB6/PB7 and then remap USART1 on. For the remap to function the AFIO clock needs to be enabled.

[JLEE.61]

Hi Clive

Thanks for quickly response.

​

You mean that below?

================================================

__HAL_AFIO_REMAP_I2C1_DISABLE();

 __HAL_RCC_USART1_CLK_ENABLE();

​

 GPIO_InitStruct.Pin = GPIO_PIN_6;

 GPIO_InitStruct.Mode = GPIO_MODE_INPUT;

 GPIO_InitStruct.Pull = GPIO_NOPULL;

 HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);

​

 GPIO_InitStruct.Pin = GPIO_PIN_7;

 GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;

 GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;

 HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);

​

 __HAL_AFIO_REMAP_USART1_ENABLE();

 __HAL_RCC_AFIO_CLK_ENABLE();  

================================================

Could you let me know the more detail information?

​

Thanks.

​

[Tesla DeLorean]

You need to enable the AFIO clock BEFORE you use things dependent on it, not after.

Try a more rational ordering..

__HAL_RCC_AFIO_CLK_ENABLE();

__HAL_RCC_USART1_CLK_ENABLE();

__HAL_AFIO_REMAP_I2C1_DISABLE();

__HAL_AFIO_REMAP_USART1_ENABLE();

[JLEE.61]

I tried it in the way you told me, but it did not work

In my pins configuration,

1. I2C1 = not use

2. I2C2(PB10-SCL, PB11-SDA) is work well.

3. UART3(PC11-RX, PC10-TX) is work well too.

4. UART1(PB6-TX, PB7-RX) is work well too.

5. UART1(PB6-RX, PB7-TX) dose not work.

Is there any other way?

[Piranha]

"5. UART1(PB6-RX, PB7-TX) dose not work."

Read the datasheet - there is no such mode in it! You can't set any pin to any function.

[JLEE.61]

Hi Piranha

​

I know that default USART1 are PB6-TX, PB​7-RX as the datasheet.

Our HW team has opposite designed the PIN.

Is it really impossible?

Thanks.

[Tesla DeLorean]

What is the complete/specific part number of the chip you are using? ST has a range of parts with assorted capabilities and dies.

https://www.st.com/resource/en/datasheet/cd00161566.pdf

The USART1 remapping to PB6/PB7 should be viable, but we're talking 10 year old parts, and I've moved on from them. The F1 family had peripheral level remapping, newer families have a richer pin muxing fabric which affords more/different opportunities.

>>Our HW team has opposite designed the PIN.

They swapped the TX and RX usage?

[JLEE.61]

I'm using the STM32F103RBT7.

let me know if you have detail instructions or related doc to remapping.

Thanks.