SPI Slave Receive Interrupt

[EthanMankins]

I am trying to make a very simple SPI ISR to read the RXDR and store the value to a buffer. However, I cannot get the ISR to even trigger without using HAL_SPI_Receive_IT(). I do not want to use the callbacks or the default IRQ generated by cube. I currently just have the following in my ISR:

void spiISR(SPI_HandleTypeDef *hspi){
	if (__HAL_SPI_GET_FLAG(&hspi1, SPI_FLAG_RXNE)) {

		rxBuffer[rxIndex] = SPI1->RXDR;
		// Increment index and wrap around if necessary
		rxIndex = (rxIndex + 1) % RX_BUFFER_SIZE;

		__HAL_SPI_CLEAR_OVRFLAG(&hspi1);

	}
}

Since I don't want to use the generated IRQ I do this:

void SPI1_IRQHandler(void)
{
  /* USER CODE BEGIN SPI1_IRQn 0 */
	spiISR(&hspi1);
	return;
  /* USER CODE END SPI1_IRQn 0 */
  HAL_SPI_IRQHandler(&hspi1);
  /* USER CODE BEGIN SPI1_IRQn 1 */

  /* USER CODE END SPI1_IRQn 1 */
}

I have turned on the following:

  MX_SPI1_Init();
  /* USER CODE BEGIN 2 */
  HAL_NVIC_EnableIRQ(SPI1_IRQn);
  __HAL_SPI_ENABLE_IT(&hspi1, SPI_IT_RXNE);

This would leave me to believe that the ISR should trigger when the fifo is not empty; however that is not the case.
I have ensured data is being transferred to the board on an oscilloscope, but the board shows no indication of receiving data

[gbm]

Have you configured the SPI? Show the code.

[PGump.1]

Hi,

Part of the problem is - you are not clearing the IRQ in your handler.

Oops - cancel the above - I was thinking of another brand device (not ST)...

Kind regards
Pedro

[EthanMankins]

Hi @gbm ,
Here is my Initialization for the spi slave

static void MX_SPI1_Init(void)
{

  /* USER CODE BEGIN SPI1_Init 0 */

  /* USER CODE END SPI1_Init 0 */

  /* USER CODE BEGIN SPI1_Init 1 */

  /* USER CODE END SPI1_Init 1 */
  /* SPI1 parameter configuration*/
  hspi1.Instance = SPI1;
  hspi1.Init.Mode = SPI_MODE_SLAVE;
  hspi1.Init.Direction = SPI_DIRECTION_2LINES;
  hspi1.Init.DataSize = SPI_DATASIZE_8BIT;
  hspi1.Init.CLKPolarity = SPI_POLARITY_LOW;
  hspi1.Init.CLKPhase = SPI_PHASE_2EDGE;
  hspi1.Init.NSS = SPI_NSS_SOFT;
  hspi1.Init.FirstBit = SPI_FIRSTBIT_MSB;
  hspi1.Init.TIMode = SPI_TIMODE_DISABLE;
  hspi1.Init.CRCCalculation = SPI_CRCCALCULATION_DISABLE;
  hspi1.Init.CRCPolynomial = 0x0;
  hspi1.Init.NSSPMode = SPI_NSS_PULSE_DISABLE;
  hspi1.Init.NSSPolarity = SPI_NSS_POLARITY_LOW;
  hspi1.Init.FifoThreshold = SPI_FIFO_THRESHOLD_01DATA;
  hspi1.Init.TxCRCInitializationPattern = SPI_CRC_INITIALIZATION_ALL_ZERO_PATTERN;
  hspi1.Init.RxCRCInitializationPattern = SPI_CRC_INITIALIZATION_ALL_ZERO_PATTERN;
  hspi1.Init.MasterSSIdleness = SPI_MASTER_SS_IDLENESS_00CYCLE;
  hspi1.Init.MasterInterDataIdleness = SPI_MASTER_INTERDATA_IDLENESS_00CYCLE;
  hspi1.Init.MasterReceiverAutoSusp = SPI_MASTER_RX_AUTOSUSP_DISABLE;
  hspi1.Init.MasterKeepIOState = SPI_MASTER_KEEP_IO_STATE_DISABLE;
  hspi1.Init.IOSwap = SPI_IO_SWAP_DISABLE;
  if (HAL_SPI_Init(&hspi1) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN SPI1_Init 2 */

  /* USER CODE END SPI1_Init 2 */

}

[EthanMankins · Accepted solution]

Thank you for the responses @PGump.1 and @gbm, 
I have found that I needed to call __HAL_SPI_ENABLE(&hspi1); to get the interrupt to trigger however the data coming in seems random. I try sending 1-8 to this slave, and the data shows correctly on oscilloscope; however, I just get repeating sequences of:

64 192 224 1 1 1 129 1 

                                                       
20 12 14 8 16 16 24 16 

 

Sometimes other randoms sequences appear too, I'm not seeing any correlation between these numbers. However, I will likely create a new post since this no longer pertains to the ISR not triggering.