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is there way to use ad5940 without interrupt or GPIO interrupt pin?

Category: Software
Product Number: ad5940

Hi i want to use AD5940 with our Hardware problem is we have limited IO pins for AD5940 , so we decided to use SPI pins and Chip select for AD5940 ICs, so we are not gonna use external reset from MCU and Interrupt GPIO. i looked at example code and the code is mainly for interrupt controller. so basically looking to use ad5940 without interrupt controller or with interrupt controller but no external GPIO pins. what are the option available and also is there sample code ?

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  • Hi,

    You will have to add 


    function inside AD5940_Main() before 

    ImpedanceShowResult(AppBuffImpedance, temp,++counter); function.

    /* Depending on the data type, do appropriate data pre-process before return back to controller */
    int32_t AppIMPDataProcess(int32_t * const pData, uint32_t *pDataCount)
      uint32_t DataCount = *pDataCount;
      uint32_t ImpResCount = DataCount/4;
      fImpPol_Type * const pOut = (fImpPol_Type*)pData;
      iImpCar_Type * pSrcData = (iImpCar_Type*)pData;
      *pDataCount = 0;
      DataCount = (DataCount/4)*4;/* We expect RCAL data together with Rz data. One DFT result has two data in FIFO, real part and imaginary part.  */
      /* Convert DFT result to int32_t type */
      for(uint32_t i=0; i<DataCount; i++)
        pData[i] &= 0x3ffff; /* @todo option to check ECC */
        if(pData[i]&(1L<<17)) /* Bit17 is sign bit */
          pData[i] |= 0xfffc0000; /* Data is 18bit in two's complement, bit17 is the sign bit */
      for(uint32_t i=0; i<ImpResCount; i++)
        iImpCar_Type *pDftRcal, *pDftRz;
        pDftRcal = pSrcData++;
        pDftRz = pSrcData++;
        float RzMag,RzPhase;
        float RcalMag, RcalPhase;
        RcalMag = sqrt((float)pDftRcal->Real*pDftRcal->Real+(float)pDftRcal->Image*pDftRcal->Image);
        RcalPhase = atan2(-pDftRcal->Image,pDftRcal->Real);
        RzMag = sqrt((float)pDftRz->Real*pDftRz->Real+(float)pDftRz->Image*pDftRz->Image);
        RzPhase = atan2(-pDftRz->Image,pDftRz->Real);
        RzMag = RcalMag/RzMag*AppIMPCfg.RcalVal;
        RzPhase = RcalPhase - RzPhase;
        //printf("V:%d,%d,I:%d,%d ",pDftRcal->Real,pDftRcal->Image, pDftRz->Real, pDftRz->Image);
        pOut[i].Magnitude = RzMag;
        pOut[i].Phase = RzPhase;
      *pDataCount = ImpResCount; 
      AppIMPCfg.FreqofData = AppIMPCfg.SweepCurrFreq;
      /* Calculate next frequency point */
      if(AppIMPCfg.SweepCfg.SweepEn == bTRUE)
        AppIMPCfg.FreqofData = AppIMPCfg.SweepCurrFreq;
        AppIMPCfg.SweepCurrFreq = AppIMPCfg.SweepNextFreq;
        AD5940_SweepNext(&AppIMPCfg.SweepCfg, &AppIMPCfg.SweepNextFreq);
      return 0;

    Output data is stored in pOut[].