STM32 SPI Receive interrupt does not trigger

Question

I want to communicate 2 STM32 boards using SPI. I use one board as master and the other one as slave.

I can transmit and receive using HAL_SPI_Transmit() and HAL_SPI_Receive() functions. Now I want to configure slave to receive in interrupt mode but this interrupt never triggers.

Here is the code I use for both boards:

Master

int main(void)
{
  uint8_t txdata [] = {0x01, 0x02, 0x03, 0x04};

  HAL_Init();

  SystemClock_Config();

  MX_GPIO_Init();

  MX_SPI2_Init();

  while (1)
  {
    HAL_SPI_Transmit(&hspi2, txdata, 4, 20);
    HAL_Delay(2000);
  }
}
static void MX_SPI2_Init(void)
{
  hspi2.Instance = SPI2;
  hspi2.Init.Mode = SPI_MODE_MASTER;
  hspi2.Init.Direction = SPI_DIRECTION_2LINES;
  hspi2.Init.DataSize = SPI_DATASIZE_8BIT;
  hspi2.Init.CLKPolarity = SPI_POLARITY_LOW;
  hspi2.Init.CLKPhase = SPI_PHASE_1EDGE;
  hspi2.Init.NSS = SPI_NSS_SOFT;
  hspi2.Init.BaudRatePrescaler = SPI_BAUDRATEPRESCALER_2;
  hspi2.Init.FirstBit = SPI_FIRSTBIT_MSB;
  hspi2.Init.TIMode = SPI_TIMODE_DISABLE;
  hspi2.Init.CRCCalculation = SPI_CRCCALCULATION_DISABLE;
  hspi2.Init.CRCPolynomial = 7;
  if (HAL_SPI_Init(&hspi2) != HAL_OK)
  {
    Error_Handler();
  }
}

void HAL_SPI_MspInit(SPI_HandleTypeDef* hspi)
{
  GPIO_InitTypeDef GPIO_InitStruct = {0};

  if(hspi->Instance==SPI2)
  {
    __HAL_RCC_SPI2_CLK_ENABLE();

    __HAL_RCC_GPIOB_CLK_ENABLE();

    GPIO_InitStruct.Pin = GPIO_PIN_15|GPIO_PIN_14|GPIO_PIN_13;
    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
    GPIO_InitStruct.Alternate = GPIO_AF0_SPI2;
    HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);
  }
}

Slave

int main(void)
{
  HAL_Init();

  SystemClock_Config();

  MX_GPIO_Init();

  MX_SPI2_Init();

  HAL_SPI_Receive_IT(&hspi2, rxdata, 4);

  while (1)
  {

  }
}
void HAL_SPI_RxCpltCallback(SPI_HandleTypeDef *hspi)
{
  if (hspi->Instance == SPI2) 
  {
    printf("%d", rxdata[0]);
    printf("%d", rxdata[1]);
    printf("%d", rxdata[2]);
    printf("%d", rxdata[3]);
    printf("\r\n");

    rxdata[0] = 0;
    rxdata[1] = 0;
    rxdata[2] = 0;
    rxdata[3] = 0;

    HAL_SPI_Receive_IT(&hspi2, rxdata, 4);
  }
}

void HAL_SPI_MspInit(SPI_HandleTypeDef* hspi)
{
  GPIO_InitTypeDef GPIO_InitStruct = {0};

  if(hspi->Instance==SPI2)
  {
    __HAL_RCC_SPI2_CLK_ENABLE();

    __HAL_RCC_GPIOB_CLK_ENABLE();

    GPIO_InitStruct.Pin = GPIO_PIN_15|GPIO_PIN_14|GPIO_PIN_13;
    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
    GPIO_InitStruct.Alternate = GPIO_AF0_SPI2;
    HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);

    HAL_NVIC_SetPriority(SPI2_IRQn, 0, 0);
    HAL_NVIC_EnableIRQ(SPI2_IRQn);
  }
}

void SPI2_IRQHandler(void)
{
  HAL_SPI_IRQHandler(&hspi2);
}

Unknown Unknown · Accepted Answer · 2019-08-02T12:00:26

Turns out that BaudPreescaler was set as SPI_BAUDRATEPRESCALER_2 in both master and slave but for some reason this variable had different values in each project.

This made communication not work properly and receive noise.

STM32 SPI Receive interrupt does not trigger

1 Answers