HAL_UART_Receive_IT is not working

[KaushikSTM32]

Originally a reply in this thread - split as a separate question.

---

Hello 

My blocking mode is working with "HAL_UART_Receive(&huart4, temp, 1, 100);"

Nonblocking mode is not working

Can you suggest anything to check?

I have defined as said

/* USER CODE BEGIN 2 */

HAL_UART_Receive_IT(&huart4, temp, 1);

/* USER CODE END 2 */

and

/* USER CODE BEGIN 4 */

void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)
{
  HAL_UART_Receive_IT(&huart4, temp, 1);
  HAL_UART_Transmit(&huart4, temp, 1, 100);
}

/* USER CODE END 4 */

[KaushikSTM32]

Sir,

Thanks for the support.

I tried to disable this while loop in Error_Handler also, but still when I send the first byte It stopped responding.

I think it never reaches to HAL_UART_RxCpltCallback this function, It stops before.

I did this, I don't know whether this can serve my logic to disable the error handler.

void Error_Handler(void)

{

/* USER CODE BEGIN Error_Handler_Debug */

/* User can add his own implementation to report the HAL error return state */

// __disable_irq();

// while (1)

{

}

/* USER CODE END Error_Handler_Debug */

}

Thanks,

[Andrew Neil]

Please follow the instructions for posting source code:

https://community.st.com/t5/community-guidelines/how-to-insert-source-code/ta-p/693413

---

@KaushikSTM32 wrote:

I tried to disable this while loop in Error_Handler ,

---

That's not a sensible thing to do!

If your code reaches that point, it means something has failed.

You need to find the reason for that failure - and fix that.

So the first thing you need to do is find where the Error Handler is being called, and why.

[KaushikSTM32]

Andrew Sir,

Shall I know which ISR will be executed first when Controller receives the first byte?

I have chosen Word length 8 with no parity so I think this should be (UART_RxISR_8BIT)  executed first, am I right?

Shall I put toggling on that ISR to know whether it is executing or not with extern variable?

Thanks,

[Andrew Neil]

Before you do anything else, you need to find out where that error is occurring!

[KaushikSTM32]

Thank you sir for the useful information.

[KaushikSTM32]

void UART4_IRQHandler(void) this ISR routine is not executed while receiving.

[Karl Yamashita]

Check the stm32xxxhal_msp.c file to be sure any reference to UART4 are there. May look something like this though port pins might be different. 

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_D2PCLK1;
    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
    PA0     ------> UART4_TX
    PA1     ------> UART4_RX
    */
    GPIO_InitStruct.Pin = GPIO_PIN_0|GPIO_PIN_1;
    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
    GPIO_InitStruct.Alternate = GPIO_AF8_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 */
  }

[Andrew Neil]

---

@KaushikSTM32 wrote:

UART4_IRQHandler(void) this ISR routine is not executed while receiving.

---

You still haven't confirmed that you have enabled the interrupt.

Obviously, if the interrupt is not enabled, its handler will never get called!

In the code @Karl Yamashita just posted, this is where the interrupt gets enabled:

    /* UART4 interrupt Init */
    HAL_NVIC_SetPriority(UART4_IRQn, 0, 0);
    HAL_NVIC_EnableIRQ(UART4_IRQn);

[KaushikSTM32]

Sir,

I went further into it I had monitored the RDR and it showed the received value correct. 

I also monitored RXNE flag it was setting at 1 while receiving the first byte.

And also RXNEIE is 1. Interrupt routine should be called but it reset RXNE and debugger got lost, not executing anything.

I have checked NVIC in startup file all seems ok.

Yes Sir, Interrupt is enabled. I have introduced it also just before while loop.

   HAL_NVIC_SetPriority(USART3_IRQn, 0, 0);
   HAL_NVIC_EnableIRQ(USART3_IRQn);  // Example for USART1
   USART3->CR1 |= USART_CR1_RXNEIE;  // Enable RX interrupt

Thanks,

[KaushikSTM32 · Accepted solution]

Yes sir its enabled.

Port pins are also correct.

void HAL_UART_MspInit(UART_HandleTypeDef* huart)
{
  GPIO_InitTypeDef GPIO_InitStruct = {0};
  RCC_PeriphCLKInitTypeDef PeriphClkInit = {0};
  if(huart->Instance==USART3)
  {
  /* USER CODE BEGIN USART3_MspInit 0 */

  /* USER CODE END USART3_MspInit 0 */

  /** Initializes the peripherals clocks
  */
    PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_USART3;
    PeriphClkInit.Usart3ClockSelection = RCC_USART3CLKSOURCE_PCLK1;
    if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit) != HAL_OK)
    {
      Error_Handler();
    }

    /* Peripheral clock enable */
    __HAL_RCC_USART3_CLK_ENABLE();

    __HAL_RCC_GPIOC_CLK_ENABLE();
    /**USART3 GPIO Configuration
    PC10     ------> USART3_TX
    PC11     ------> USART3_RX
    */
    GPIO_InitStruct.Pin = GPIO_PIN_10|GPIO_PIN_11;
    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(GPIOC, &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 */

  }