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SPI slave bidirectional

Question asked by chris wedgwood on Aug 25, 2017

I have a difficulty with ST32F030 and Slave SPI

 

I'm trying to have it respond to an spi command:-

 

Master sends 0x05, slave responds with an array of 7 bytes.

It kind of works the first time, but then loses sync, and get OVR bit set. I can't figure out why.

 

Heres the code:-

int main(void)
{

   HAL_Init();

   /* Configure the system clock */
   SystemClock_Config();

   /* Initialize all configured peripherals */
   MX_SPI1_Init();

   spi_init();


   while (1)
   {
      HAL_SPI_Receive_IT(&hspi1, &spiData[0], 1);
   }

}

 

/* SPI1 init function */
static void MX_SPI1_Init(void)
{

   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_1EDGE;
   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 = 7;
   hspi1.Init.CRCLength = SPI_CRC_LENGTH_DATASIZE;
   hspi1.Init.NSSPMode = SPI_NSS_PULSE_DISABLE;

   /* SPi priority interrupt configuration */
   HAL_NVIC_SetPriority(SPI1_IRQn, 1, 1);

   if (HAL_SPI_Init(&hspi1) != HAL_OK)
   {
      Error_Handler();
   }

}

 

void SPI1_IRQHandler(void)
{
   HAL_SPI_IRQHandler(&hspi1);
}

 

uint8_t spiData[8];

uint8_t edgesmsg[7];

 

void spi_interrupt()
{
   uint8_t c;


   c = spiData[0];

   if ( c == 0x05)
      HAL_SPI_Transmit(&hspi1, edgesmsg, 7, 1000);

}

 

Any suggestions gratefully received..

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