Change uart settings and pinout runtime

[BRonc.1]

Hi!

I'm working with a STM32C071 and I would like to change uart1 pinout and settings runtime: I've defined USART1 (in the .ioc file) as PB2 (RX) and PC14 (TX). After boot, I would like to change the USART1 pinout as PB6 (TX) and PB7 (RX). So I've written the following:

void UART_Reconfigure(UART_HandleTypeDef *huart2change,
                      GPIO_TypeDef *newTXPort, uint16_t newTXPin,
                      GPIO_TypeDef *newRXPort, uint16_t newRXPin,
                      GPIO_TypeDef *oldTXPort, uint16_t oldTXPin,
                      GPIO_TypeDef *oldRXPort, uint16_t oldRXPin) {

    // 1. Abilita il clock per i vecchi GPIO se necessario (PRIMA di deinizializzarli)
    if (oldTXPort == GPIOA || oldRXPort == GPIOA) {
        __HAL_RCC_GPIOA_CLK_ENABLE();
    }
    if (oldTXPort == GPIOB || oldRXPort == GPIOB) {
        __HAL_RCC_GPIOB_CLK_ENABLE();
    }
    if (oldTXPort == GPIOC || oldRXPort == GPIOC) {
        __HAL_RCC_GPIOC_CLK_ENABLE();
    }

    // 2. Disabilita la UART prima di cambiare i pin
    HAL_UART_DeInit(huart2change);

    // 3. Deinizializza i vecchi pin
    HAL_GPIO_DeInit(oldTXPort, oldTXPin);
    HAL_GPIO_DeInit(oldRXPort, oldRXPin);

    // 4. Abilita il clock per i nuovi GPIO
    if (newTXPort == GPIOA || newRXPort == GPIOA) {
        __HAL_RCC_GPIOA_CLK_ENABLE();
    }
    if (newTXPort == GPIOB || newRXPort == GPIOB) {
        __HAL_RCC_GPIOB_CLK_ENABLE();
    }
    if (newTXPort == GPIOC || newRXPort == GPIOC) {
        __HAL_RCC_GPIOC_CLK_ENABLE();
    }

    // 5. Configura i nuovi pin
    GPIO_InitTypeDef GPIO_InitStruct = {0};

    // Configura TX
    GPIO_InitStruct.Pin = newTXPin;
    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
    GPIO_InitStruct.Alternate = GPIO_AF0_USART1;  // USART1 su PB6 (Verifica per altri pin!)
    HAL_GPIO_Init(newTXPort, &GPIO_InitStruct);

    // Configura RX
    GPIO_InitStruct.Pin = newRXPin;
    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;  // RX in modalità AF_PP
    GPIO_InitStruct.Pull = GPIO_PULLUP;      // Pull-up abilitato
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
    GPIO_InitStruct.Alternate = GPIO_AF0_USART1;  // USART1 su PB7 (Verifica per altri pin!)
    HAL_GPIO_Init(newRXPort, &GPIO_InitStruct);

    // 6. Reinizializza la UART
    huart2change->Instance = USART1;
    huart2change->Init.BaudRate = 115200;
    huart2change->Init.WordLength = UART_WORDLENGTH_8B;
    huart2change->Init.StopBits = UART_STOPBITS_1;
    huart2change->Init.Parity = UART_PARITY_NONE;
    huart2change->Init.Mode = UART_MODE_TX_RX;
    huart2change->Init.HwFlowCtl = UART_HWCONTROL_NONE;
    huart2change->Init.OverSampling = UART_OVERSAMPLING_16;
    huart2change->Init.OneBitSampling = UART_ONE_BIT_SAMPLE_DISABLE;
    huart2change->Init.ClockPrescaler = UART_PRESCALER_DIV1;
    huart2change->AdvancedInit.AdvFeatureInit = UART_ADVFEATURE_NO_INIT;

    if (HAL_UART_Init(huart2change) != HAL_OK) {
        // Gestione errore
        Error_Handler();
    }
    if (HAL_UARTEx_SetTxFifoThreshold(huart2change, UART_TXFIFO_THRESHOLD_1_8) != HAL_OK)
    {
      Error_Handler();
    }
    if (HAL_UARTEx_SetRxFifoThreshold(huart2change, UART_RXFIFO_THRESHOLD_1_8) != HAL_OK)
    {
      Error_Handler();
    }
    if (HAL_UARTEx_DisableFifoMode(huart2change) != HAL_OK)
    {
      Error_Handler();
    }
}

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I only have to launch:

UART_Reconfigure(&huart1, GPIOB, GPIO_PIN_6, GPIOB, GPIO_PIN_7, GPIOC, GPIO_PIN_14, GPIOB, GPIO_PIN_2);

But it doesn't work.

What am I missing?

Thanks

[Javier1]

You will engage much more users if you comment your code in english, is good practice in general.

>>But it doesn't work.

How is it not working, is HAL_UART_Init returning an error? Have you tried using those PB6  PB7 pins from the beginning in case is not working?

Edit: how about looking at 

HAL_UART_MspInit

Maybe you need to enable UART CLK before declaring those new pins?

   /* UART1 clock enable */
    __HAL_RCC_UART1_CLK_ENABLE();

    // 4. Abilita il clock per i nuovi GPIO
    if (newTXPort == GPIOA || newRXPort == GPIOA) {
        __HAL_RCC_GPIOA_CLK_ENABLE();
    }
    if (newTXPort == GPIOB || newRXPort == GPIOB) {
        __HAL_RCC_GPIOB_CLK_ENABLE();
    }
    if (newTXPort == GPIOC || newRXPort == GPIOC) {
        __HAL_RCC_GPIOC_CLK_ENABLE();
    }

[BRonc.1]

Hi Xavier,

thanks for your reply. I have no output on serial. Now i've noticed that maybe there is a conflict in pinout definition: if I set uart1 as PB6 and PB7 directly in the .ioc config, I can see that USART1 definition has a warning:

I will try to solve this

[KnarfB]

yellow is only a warning (hint) that not all options for Hardware Flow Control will be available, because some will conflict with other settings.

Debug-step through your code and compare the actual register settings with the expected ones.

hth

KnarfB

[BRonc.1]

Hi all,

I've solved. I was missing a setting in the build environment. Thanks to all!

[Ozone]

This internal peripheral routing is usually very straightforward.
You can have both sets of UART Tx / Rx pins configured and working at the same time, if that makes sense for your application.

Never tried it on a C0xx, though.