How to read ADS1298 ID register, write other registers

Hi,

I have a SR open(SR#: 1-1893850773) in ti-china@ti.com, they recommend me to this forum.

I'm operating ADS1298 with STM32F4xx, but I always fail to run command RREG and WREG.

so that I always get DRDY signal with rate of SPS 250, which is the default value after reset.

Following is my code, which I wrote according to the user manual with the reference of a lot of web pages.

I hope I can get some help from you, pointing where I'm wrong,

or you can give a copy of sample code that I can successfully read out the ID register or write into other configuration registers(because they said e2e forum has source code).

My dev environment is: ADS1298,STM32F407VGTx,Keil uVision5,STM32Cube_FW_F4_V1.7.0

Also, I attached one snapshot of timming diagram I got out.

Thanks

Marcus

  uint8_t datarx[26];

  SetCSValue(0);                                //Set CS PIN LOW

  SetPWDNValue(1);                       //Set PWDN PIN HIGH

  SetRESETValue(1);                         //Set RESET PIN HIGH

  HAL_Delay(1000);                          //Sleep 1 Second

  SetRESETValue(0);                         //Set RESET PIN LOW

  HAL_Delay(100);                            //Sleep 100 mini second

  SetRESETValue(1);                         //Set RESET PIN HIGH

  HAL_Delay(100);                            //Sleep 100 mini second

  //SDATAC

  SDATAC_Command();                 //Send SDATAC Command

  //RREG

  memset(datarx,0,sizeof(datarx));         

  RREG_Command(0x20,0,datarx,1);        //RREG Command,  read only ID register, aways return 0x00,check the diagram for command sequence

void SDATAC_Command()

{

  uint8_t data = 0x11;

  SetCSValue(0);

  HAL_SPI_Transmit(&hspi2,&data,1,1);

  HAL_Delay(1);       //Sleep 1 mini second then set CS HIGH

  SetCSValue(1);

}

void RREG_Command(uint8_t opcode1, uint8_t opcode2, uint8_t* datarx, uint8_t len)

{

  uint8_t datatx[26];

  memset(datatx,0,sizeof(datatx));

  SetCSValue(0);

  HAL_SPI_Transmit(&hspi2,&opcode1,1,1);

  HAL_Delay(1);

  HAL_SPI_Transmit(&hspi2,&opcode2,1,1);

  HAL_Delay(1);

  for(int i=0;i<len;i++)

  {

    HAL_SPI_TransmitReceive(&hspi2,&datatx[i],&datarx[i],1,1);

  }

  HAL_Delay(1);

  SetCSValue(1);

}

With the following SPI configuration:

  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_DISABLED;

  hspi2.Init.CRCCalculation = SPI_CRCCALCULATION_DISABLED;

  hspi2.Init.CRCPolynomial = 10;

  HAL_SPI_Init(&hspi2);