SPI MISO data is not reflecting on the receive buffer

RE: SPI MISO data is not reflecting on the receive buffer

guomingyi — Fri, 05 May 2023 09:16:26 GMT

sorry, I make a stupid mistakes:

#define MISO_PIN_MASTER NRF_DT_GPIOS_TO_PSEL_BY_IDX(DT_NODELABEL(spismiso), gpios, 0)
#define MISO_PIN_SLAVE NRF_DT_GPIOS_TO_PSEL_BY_IDX(DT_NODELABEL(spimmiso), gpios, 0)

now all is well.
thanks.

RE: SPI MISO data is not reflecting on the receive buffer

Chinna — Thu, 16 Aug 2018 09:20:38 GMT

Hi Jorgen,

As per your input, After updating the m_rx_buf_len to add read/write command size the problem got resolved.

Once again thanks for the support.

Thanks & Regards,

Chinnasamy.

RE: SPI MISO data is not reflecting on the receive buffer

Jørgen Holmefjord — Wed, 15 Aug 2018 14:53:55 GMT

Note that most SPI devices will output data after you are done sending the command/address/etc. The SPI peripheral on nRF52 devices will start filling the RX buffer simultaneously with TX buffer being clocked out. If you send 4 bytes and expect 4 bytes back after TX is done, you need to set the RX buffer size to 8, and discard the first 4 bytes.

Please have a look at the sequence diagrams in the SPI peripheral documentation

RE: SPI MISO data is not reflecting on the receive buffer

Chinna — Thu, 09 Aug 2018 07:04:07 GMT

Ho Jorgen,

Added m_rx_buf_len =1 in NVMWaitToCompleteExecution() function and m_rx_buf_len = 4 in NVMRead().

But we are reading 0xFF in m_rx_buf[] indexes. Always 0xFF in the receive buffer.

Is there any compatibility related issue on the SPI API's with the softdevice enabled condition?

Kindly suugest us.

Thanks & Regards,

Chinnasamy

RE: SPI MISO data is not reflecting on the receive buffer

Jørgen Holmefjord — Tue, 07 Aug 2018 12:02:24 GMT

What is the value of m_rx_buf_len?

RE: SPI MISO data is not reflecting on the receive buffer

Chinna — Tue, 07 Aug 2018 11:53:29 GMT

Hi Jorgen,

I am using SDK 12.3.0, Softdevice 132.

I am refering following link for SPI initialization:

http://infocenter.nordicsemi.com/index.jsp?topic=%2Fcom.nordic.infocenter.sdk52.v0.9.1%2Fhardware_driver_spi_master.html&cp=4_0_0_2_7

I am interfacing M95M02 EEPROM.

Here is the code snippet for your review.

SPI Initialization code.

void eepromInit()
{
   ret_code_t err_code =0;
   nrf_drv_spi_config_t spi_config = NRF_DRV_SPI_DEFAULT_CONFIG;
   spi_config.ss_pin = SPI_SS_PIN;
    spi_config.miso_pin = SPI_MISO_PIN;
    spi_config.mosi_pin = SPI_MOSI_PIN;
    spi_config.sck_pin = SPI_SCK_PIN;

   err_code = nrf_drv_spi_init(&spi, &spi_config,spi_master_event_handler);
  if (err_code != NRF_SUCCESS)
  {
    // Initialization failed. Take recovery action.
  }
  while(1)
  {
     NVMWrite(0x100,"data" , 1);
     nrf_delay_ms(10);
    NVMRead(0x100,"data" , 1);
  }
}

void spi_master_event_handler(nrf_drv_spi_evt_t const * event)
{
    switch (event->type)
  {
   case NRF_DRV_SPI_EVENT_DONE:
    // Inform application that transfer is completed.
    m_transfer_completed = true;
   break;
   default:
    // No implementation needed.
   break;
    }
}

void NVMWriteEnable(bool flag)
{
  memset(m_rx_buf, 0, m_rx_buf_len);
  memset(m_tx_buf, 0, m_tx_buf_len);

  m_tx_buf[0] = (flag == 1)? 6: 4; //(flag == 1)? EEPROM_WREN: EEPROM_WRDI;
  m_tx_buf_len = 1;

  if(nrf_drv_spi_transfer(&spi,(uint8_t const *)m_tx_buf,m_tx_buf_len,m_rx_buf,m_rx_buf_len) == NRF_SUCCESS)
  {
   m_transfer_completed = false;
   while(m_transfer_completed == false);
  }
}

void NVMWaitToCompleteExecution(void)
{

  do
  {
    memset(m_rx_buf, 0, m_rx_buf_len);
    memset(m_tx_buf, 0, m_tx_buf_len);

    m_tx_buf[0] = 5;//EEPROM_RDSR;
    m_tx_buf[1] = 0xFF;
    m_tx_buf_len = 2;

    if(nrf_drv_spi_transfer(&spi,(uint8_t const *)m_tx_buf,m_tx_buf_len,m_rx_buf,m_rx_buf_len) == NRF_SUCCESS)
    {
     m_transfer_completed = false;
     while(m_transfer_completed == false);
    }
    if((m_rx_buf[0] & 0x01) != 0)
    {
     nrf_delay_ms(10);
    }

  }while((m_rx_buf[0] & 0x01) != 0);
}

void NVMWritePage(uint32_t Address, uint8_t *const p_Buffer, uint32_t NrOfElementsInArray)
{
  memset(m_rx_buf, 0, m_rx_buf_len);
  memset(m_tx_buf, 0, m_tx_buf_len);

  m_tx_buf[0] = 2;//EEPROM_WRITE;
  m_tx_buf[1] = 0x00;
  m_tx_buf[2] = 0x00;
  m_tx_buf[3] = 0x00;

  m_tx_buf[4] = 0x50;
  m_tx_buf[5] = 0x50;
  m_tx_buf[6] = 0x50;
  m_tx_buf[7] = 0x50;

  m_tx_buf_len = 4 + 4;

  if(nrf_drv_spi_transfer(&spi,(uint8_t const *)m_tx_buf,m_tx_buf_len,m_rx_buf,m_rx_buf_len) == NRF_SUCCESS)
  {
   m_transfer_completed = false;
   while(m_transfer_completed == false);
  }
}

void NVMWrite(uint32_t Address, uint8_t *const p_Buffer, uint32_t NrOfElementsInArray)
{
NVMWriteEnable(1);
NVMWritePage(0x00,"data",4);
NVMWaitToCompleteExecution();
}

void NVMRead(uint32_t Address, uint8_t *const p_Buffer, uint32_t NrOfElementsInArray)
{
  memset(m_rx_buf, 0, m_rx_buf_len);
  memset(m_tx_buf, 0, m_tx_buf_len);

  m_tx_buf[0] = 3;//EEPROM_READ;
  m_tx_buf[1] = 0x00;
  m_tx_buf[2] = 0x00;
  m_tx_buf[3] = 0x00;
  m_tx_buf_len = 4+4;

  if(nrf_drv_spi_transfer(&spi,(uint8_t const *)m_tx_buf,m_tx_buf_len,m_rx_buf,m_rx_buf_len) == NRF_SUCCESS)
  {
   m_transfer_completed = false;
   while(m_transfer_completed == false);
  }
  m_transfer_completed = false;
}

Thanks & Regards,

Chinnasamy.

RE: SPI MISO data is not reflecting on the receive buffer

Jørgen Holmefjord — Tue, 07 Aug 2018 11:42:52 GMT

Hi,

Have you checked that the SPI interface is configured with the correct pin number?

Which SDK version are you using? Can you post your code showing configuration, initialization, and transfers you are doing on the SPI peripheral?

Best regards,
Jørgen