Cofiguration UART4 from STM32H753ZIT6 Development module

[Ematic]

Hi, I’m trying to configure UART4 on the STM32H753ZIT to work with a USB-TTL converter for data transmission and reception. I can see that the STM32 is sending data, but the TTL converter isn't receiving it. I've attached the code file and the output file.

[Obaid_tanveer]

Can you provide more details ? 
Are you using this configuration -> UART4 RX TX with TTL RX TX and TTL's USB side connected to the PC?
Try Swapping RX,TX pins ,for UART we connect in the Following way:
UART4 TX -> TTL RX
UART4 RX -> TTL TX
if you're using some other configuration please specify.


If this helps, feel free to mark it as the solution

[Karl Yamashita]

First, lets make sure the USB-TTL adapter is working. Put the adapter in loop back mode by shorting the Tx to Rx. Then from the serial console, send a message on COM 5 and you should see it echo back.

Also, draw a block diagram how the devices are connected to each other.

[Tesla DeLorean]

UART_HandleTypeDef huart4;
UART_HandleTypeDef huart3;

/**
  * @brief UART4 Initialization Function
  * @PAram None
  * @retval None
  */
static void MX_UART4_Init(void)
{

  /* USER CODE BEGIN UART4_Init 0 */

  /* USER CODE END UART4_Init 0 */

  /* USER CODE BEGIN UART4_Init 1 */

  /* USER CODE END UART4_Init 1 */
  huart4.Instance = UART4;
  huart4.Init.BaudRate = 115200;
  huart4.Init.WordLength = UART_WORDLENGTH_8B;
  huart4.Init.StopBits = UART_STOPBITS_1;
  huart4.Init.Parity = UART_PARITY_NONE;
  huart4.Init.Mode = UART_MODE_TX_RX;
  huart4.Init.HwFlowCtl = UART_HWCONTROL_NONE;
  huart4.Init.OverSampling = UART_OVERSAMPLING_16;
  huart4.Init.OneBitSampling = UART_ONE_BIT_SAMPLE_DISABLE;
  huart4.Init.ClockPrescaler = UART_PRESCALER_DIV1;
  huart4.AdvancedInit.AdvFeatureInit = UART_ADVFEATURE_NO_INIT;
  if (HAL_UART_Init(&huart4) != HAL_OK)
  {
    Error_Handler();
  }
  if (HAL_UARTEx_SetTxFifoThreshold(&huart4, UART_TXFIFO_THRESHOLD_1_8) != HAL_OK)
  {
    Error_Handler();
  }
  if (HAL_UARTEx_SetRxFifoThreshold(&huart4, UART_RXFIFO_THRESHOLD_1_8) != HAL_OK)
  {
    Error_Handler();
  }
  if (HAL_UARTEx_DisableFifoMode(&huart4) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN UART4_Init 2 */

  /* USER CODE END UART4_Init 2 */

}

/**
  * @brief USART3 Initialization Function
  * @PAram None
  * @retval None
  */
static void MX_USART3_UART_Init(void)
{

  /* USER CODE BEGIN USART3_Init 0 */

  /* USER CODE END USART3_Init 0 */

  /* USER CODE BEGIN USART3_Init 1 */

  /* USER CODE END USART3_Init 1 */
  huart3.Instance = USART3;
  huart3.Init.BaudRate = 115200;
  huart3.Init.WordLength = UART_WORDLENGTH_8B;
  huart3.Init.StopBits = UART_STOPBITS_1;
  huart3.Init.Parity = UART_PARITY_NONE;
  huart3.Init.Mode = UART_MODE_TX_RX;
  huart3.Init.HwFlowCtl = UART_HWCONTROL_NONE;
  huart3.Init.OverSampling = UART_OVERSAMPLING_16;
  huart3.Init.OneBitSampling = UART_ONE_BIT_SAMPLE_DISABLE;
  huart3.Init.ClockPrescaler = UART_PRESCALER_DIV1;
  huart3.AdvancedInit.AdvFeatureInit = UART_ADVFEATURE_NO_INIT;
  if (HAL_UART_Init(&huart3) != HAL_OK)
  {
    Error_Handler();
  }
  if (HAL_UARTEx_SetTxFifoThreshold(&huart3, UART_TXFIFO_THRESHOLD_1_8) != HAL_OK)
  {
    Error_Handler();
  }
  if (HAL_UARTEx_SetRxFifoThreshold(&huart3, UART_RXFIFO_THRESHOLD_1_8) != HAL_OK)
  {
    Error_Handler();
  }
  if (HAL_UARTEx_DisableFifoMode(&huart3) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN USART3_Init 2 */

  /* USER CODE END USART3_Init 2 */

}

/**
  * @brief UART MSP Initialization
  * This function configures the hardware resources used in this example
  * @PAram huart: UART handle pointer
  * @retval None
  */
void HAL_UART_MspInit(UART_HandleTypeDef* huart)
{
  GPIO_InitTypeDef GPIO_InitStruct = {0};
  RCC_PeriphCLKInitTypeDef PeriphClkInitStruct = {0};
  if(huart->Instance==UART4)
  {
    /* USER CODE BEGIN UART4_MspInit 0 */

    /* USER CODE END UART4_MspInit 0 */

  /** Initializes the peripherals clock
  */
    PeriphClkInitStruct.PeriphClockSelection = RCC_PERIPHCLK_UART4;
    PeriphClkInitStruct.Usart234578ClockSelection = RCC_USART234578CLKSOURCE_HSI;
    if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInitStruct) != HAL_OK)
    {
      Error_Handler();
    }

    /* Peripheral clock enable */
    __HAL_RCC_UART4_CLK_ENABLE();

    __HAL_RCC_GPIOA_CLK_ENABLE();
    /**UART4 GPIO Configuration
    PA11     ------> UART4_RX
    PA12     ------> UART4_TX
    */
    GPIO_InitStruct.Pin = GPIO_PIN_11|GPIO_PIN_12;
    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
    GPIO_InitStruct.Alternate = GPIO_AF6_UART4;
    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

    /* UART4 interrupt Init */
    HAL_NVIC_SetPriority(UART4_IRQn, 0, 0);
    HAL_NVIC_EnableIRQ(UART4_IRQn);
    /* USER CODE BEGIN UART4_MspInit 1 */

    /* USER CODE END UART4_MspInit 1 */
  }
  else if(huart->Instance==USART3)
  {
    /* USER CODE BEGIN USART3_MspInit 0 */

    /* USER CODE END USART3_MspInit 0 */

  /** Initializes the peripherals clock
  */
    PeriphClkInitStruct.PeriphClockSelection = RCC_PERIPHCLK_USART3;
    PeriphClkInitStruct.Usart234578ClockSelection = RCC_USART234578CLKSOURCE_HSI;
    if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInitStruct) != HAL_OK)
    {
      Error_Handler();
    }

    /* Peripheral clock enable */
    __HAL_RCC_USART3_CLK_ENABLE();

    __HAL_RCC_GPIOD_CLK_ENABLE();
    /**USART3 GPIO Configuration
    PD8     ------> USART3_TX
    PD9     ------> USART3_RX
    */
    GPIO_InitStruct.Pin = GPIO_PIN_8|GPIO_PIN_9;
    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
    GPIO_InitStruct.Alternate = GPIO_AF7_USART3;
    HAL_GPIO_Init(GPIOD, &GPIO_InitStruct);

    /* USART3 interrupt Init */
    HAL_NVIC_SetPriority(USART3_IRQn, 0, 0);
    HAL_NVIC_EnableIRQ(USART3_IRQn);
    /* USER CODE BEGIN USART3_MspInit 1 */

    /* USER CODE END USART3_MspInit 1 */
  }

}