Migrated my code to latest STM32CubeMX v6.15.0 failing RS485/RS232 communication

[MAHENDRA_RANA]

Hello,

Previously I had CubeMX 6.13.0 and here is the code which was autogenerated and working as expected for RS485 communication, where I have manually handled the Direction pin in my code.

static void MX_LPUART1_UART_Init(void)
{
  hlpuart1.Instance = LPUART1;
  hlpuart1.Init.BaudRate = 115200;
  hlpuart1.Init.WordLength = UART_WORDLENGTH_8B;
  hlpuart1.Init.StopBits = UART_STOPBITS_1;
  hlpuart1.Init.Parity = UART_PARITY_NONE;
  hlpuart1.Init.Mode = UART_MODE_TX_RX;
  hlpuart1.Init.HwFlowCtl = UART_HWCONTROL_NONE;
  hlpuart1.Init.OneBitSampling = UART_ONE_BIT_SAMPLE_DISABLE;
  hlpuart1.AdvancedInit.AdvFeatureInit = UART_ADVFEATURE_NO_INIT;
  if (HAL_RS485Ex_Init(&hlpuart1, UART_DE_POLARITY_HIGH, 0, 0) != HAL_OK)
  {
    Error_Handler();
  }
  if (HAL_UARTEx_SetTxFifoThreshold(&hlpuart1, UART_TXFIFO_THRESHOLD_1_8) != HAL_OK)
  {
    Error_Handler();
  }
  if (HAL_UARTEx_SetRxFifoThreshold(&hlpuart1, UART_RXFIFO_THRESHOLD_1_8) != HAL_OK)
  {
    Error_Handler();
  }
  if (HAL_UARTEx_DisableFifoMode(&hlpuart1) != HAL_OK)
  {
    Error_Handler();
  }
}

Now I have updated the CubeMX version to 6.15.0 and latest stm32cube , which fails the RS485 communication:

static void MX_LPUART1_UART_Init(void)
{
  hlpuart1.Instance = LPUART1;
  hlpuart1.Init.BaudRate = 115200;
  hlpuart1.Init.WordLength = UART_WORDLENGTH_8B;
  hlpuart1.Init.StopBits = UART_STOPBITS_1;
  hlpuart1.Init.Parity = UART_PARITY_NONE;
  hlpuart1.Init.Mode = UART_MODE_TX_RX;
  hlpuart1.Init.HwFlowCtl = UART_HWCONTROL_NONE;
  hlpuart1.Init.OneBitSampling = UART_ONE_BIT_SAMPLE_DISABLE;
  hlpuart1.AdvancedInit.AdvFeatureInit = UART_ADVFEATURE_NO_INIT;
  hlpuart1.FifoMode = UART_FIFOMODE_ENABLE;
  if (HAL_UART_Init(&hlpuart1) != HAL_OK)
  {
    Error_Handler();
  }
  if (HAL_UARTEx_SetTxFifoThreshold(&hlpuart1, UART_TXFIFO_THRESHOLD_1_8) != HAL_OK)
  {
    Error_Handler();
  }
  if (HAL_UARTEx_SetRxFifoThreshold(&hlpuart1, UART_RXFIFO_THRESHOLD_1_8) != HAL_OK)
  {
    Error_Handler();
  }
  if (HAL_UARTEx_EnableFifoMode(&hlpuart1) != HAL_OK)
  {
    Error_Handler();
  }
  if (HAL_RS485Ex_Init(&hlpuart1, UART_DE_POLARITY_HIGH, 0, 0) != HAL_OK)
  {
    Error_Handler();
  }
}

Then I did these changes (re-arrange HAL_RS485Ex_Init() function position), and it works, but as this code is autogenerated multiple times which increase my re-work to arrange the code again and again.

static void MX_LPUART1_UART_Init(void)
{
  hlpuart1.Instance = LPUART1;
  hlpuart1.Init.BaudRate = 115200;
  hlpuart1.Init.WordLength = UART_WORDLENGTH_8B;
  hlpuart1.Init.StopBits = UART_STOPBITS_1;
  hlpuart1.Init.Parity = UART_PARITY_NONE;
  hlpuart1.Init.Mode = UART_MODE_TX_RX;
  hlpuart1.Init.HwFlowCtl = UART_HWCONTROL_NONE;
  hlpuart1.Init.OneBitSampling = UART_ONE_BIT_SAMPLE_DISABLE;
  hlpuart1.AdvancedInit.AdvFeatureInit = UART_ADVFEATURE_NO_INIT;
  hlpuart1.FifoMode = UART_FIFOMODE_ENABLE;
  if (HAL_UART_Init(&hlpuart1) != HAL_OK)
  {
    Error_Handler();
  }
  if (HAL_RS485Ex_Init(&hlpuart1, UART_DE_POLARITY_HIGH, 0, 0) != HAL_OK)
  {
    Error_Handler();
  }
  if (HAL_UARTEx_SetTxFifoThreshold(&hlpuart1, UART_TXFIFO_THRESHOLD_1_8) != HAL_OK)
  {
    Error_Handler();
  }
  if (HAL_UARTEx_SetRxFifoThreshold(&hlpuart1, UART_RXFIFO_THRESHOLD_1_8) != HAL_OK)
  {
    Error_Handler();
  }
  if (HAL_UARTEx_EnableFifoMode(&hlpuart1) != HAL_OK)
  {
    Error_Handler();
  }
}

As if we initialize uart or rs485 before fifo threshold setting or fifo enable then code works or else it receives the data but not transmit it or give response on TX.

Also using low level driver library in another project instead of HAL so there also the same issue. I have attached an ioc file of that project as well:

void MX_LPUART1_UART_Init(void)
{

  /* USER CODE BEGIN LPUART1_Init 0 */

  /* USER CODE END LPUART1_Init 0 */

  LL_LPUART_InitTypeDef LPUART_InitStruct = {0};

  LL_GPIO_InitTypeDef GPIO_InitStruct = {0};

  LL_RCC_SetLPUARTClockSource(LL_RCC_LPUART1_CLKSOURCE_PCLK1);

  /* Peripheral clock enable */
  LL_APB1_GRP1_EnableClock(LL_APB1_GRP1_PERIPH_LPUART1);

  LL_IOP_GRP1_EnableClock(LL_IOP_GRP1_PERIPH_GPIOB);
  /**LPUART1 GPIO Configuration
  PB10   ------> LPUART1_RX
  PB11   ------> LPUART1_TX
  PB12   ------> LPUART1_DE
  */
  GPIO_InitStruct.Pin = LL_GPIO_PIN_10|LL_GPIO_PIN_11;
  GPIO_InitStruct.Mode = LL_GPIO_MODE_ALTERNATE;
  GPIO_InitStruct.Speed = LL_GPIO_SPEED_FREQ_LOW;
  GPIO_InitStruct.OutputType = LL_GPIO_OUTPUT_PUSHPULL;
  GPIO_InitStruct.Pull = LL_GPIO_PULL_UP;
  GPIO_InitStruct.Alternate = LL_GPIO_AF_8;
  LL_GPIO_Init(GPIOB, &GPIO_InitStruct);

  GPIO_InitStruct.Pin = LL_GPIO_PIN_12;
  GPIO_InitStruct.Mode = LL_GPIO_MODE_ALTERNATE;
  GPIO_InitStruct.Speed = LL_GPIO_SPEED_FREQ_LOW;
  GPIO_InitStruct.OutputType = LL_GPIO_OUTPUT_PUSHPULL;
  GPIO_InitStruct.Pull = LL_GPIO_PULL_DOWN;
  GPIO_InitStruct.Alternate = LL_GPIO_AF_8;
  LL_GPIO_Init(GPIOB, &GPIO_InitStruct);

  /* LPUART1 interrupt Init */
  NVIC_SetPriority(USART3_LPUART1_IRQn, NVIC_EncodePriority(NVIC_GetPriorityGrouping(),0, 0));
  NVIC_EnableIRQ(USART3_LPUART1_IRQn);

  /* USER CODE BEGIN LPUART1_Init 1 */

  /* USER CODE END LPUART1_Init 1 */
  LPUART_InitStruct.PrescalerValue = LL_LPUART_PRESCALER_DIV1;
  LPUART_InitStruct.BaudRate = 115200;
  LPUART_InitStruct.DataWidth = LL_LPUART_DATAWIDTH_8B;
  LPUART_InitStruct.StopBits = LL_LPUART_STOPBITS_1;
  LPUART_InitStruct.Parity = LL_LPUART_PARITY_NONE;
  LPUART_InitStruct.TransferDirection = LL_LPUART_DIRECTION_TX_RX;
  LPUART_InitStruct.HardwareFlowControl = LL_LPUART_HWCONTROL_NONE;
  LL_LPUART_Init(LPUART1, &LPUART_InitStruct);
  LL_LPUART_SetTXFIFOThreshold(LPUART1, LL_LPUART_FIFOTHRESHOLD_1_8);
  LL_LPUART_SetRXFIFOThreshold(LPUART1, LL_LPUART_FIFOTHRESHOLD_1_8);
  LL_LPUART_EnableFIFO(LPUART1);

  /* USER CODE BEGIN WKUPType LPUART1 */

  /* USER CODE END WKUPType LPUART1 */

  LL_LPUART_Enable(LPUART1);
  LL_LPUART_Init(LPUART1, &LPUART_InitStruct);
  LL_LPUART_SetTXFIFOThreshold(LPUART1, LL_LPUART_FIFOTHRESHOLD_1_8);
  LL_LPUART_SetRXFIFOThreshold(LPUART1, LL_LPUART_FIFOTHRESHOLD_1_8);
  LL_LPUART_EnableDEMode(LPUART1);
  LL_LPUART_SetDESignalPolarity(LPUART1, LL_LPUART_DE_POLARITY_LOW);
  LL_LPUART_SetDEAssertionTime(LPUART1, 0);
  LL_LPUART_SetDEDeassertionTime(LPUART1, 0);
  LL_LPUART_EnableFIFO(LPUART1);
  LL_LPUART_Enable(LPUART1);
  /* USER CODE BEGIN LPUART1_Init 2 */

  /* USER CODE END LPUART1_Init 2 */

}

Surprising by latest cubemx version why function calling sequence updated and code suddenly stopped working after upgrade.

Please any expert or ST Employee can help us...

Thanks & Regards,

Mahendra Rana

[Souhaib MAZHOUD]

Hello @MAHENDRA_RANA 

Thank you for binging this issue to our attention, 

I will check it internally and get back to you asap.

KR,

Souhaib