ADuCM355: Impedance measurements problems

Hello,

I am running the EIS Example from <www.analog.com/.../eval-aducm355qspz-ug-1308.pdf>.

I am calibrating the impedance measurements of a dummy cell. So, I note that the parameters such as RFilter, RLoad and LPGain do not change my values, and the only parameter which is necessary to change during the sweep is the HSGain. However, it can measure the impedance in 0.1Hz right, but not in 1Hz and in 10Hz. The weird thing is that it can turn back to read right again in the 100Hz, getting right values in 1000Hz, and 10000Hz also. 

Is it another parameter that I should try to change to measure right in these intermediary frequencies? And is it possible to change pImpedanceCfg->PwrMod = AFEPWR_LP parameter in running time?

Could anyone advise me on how to correct this issue?

Best regards!

  • 0
    •  Analog Employees 
    on Oct 5, 2021 6:21 AM

    Hi,

     You may use the impedance.c code attached, for measuring through the entire frequency range.

      You will have to add 

    uint32_t SeqWaitAddr[3];

    in impedance.h file.

    /******************************************************************************
    Copyright (c) 2017-2019 Analog Devices, Inc. All Rights Reserved.
    
    This software is proprietary to Analog Devices, Inc. and its licensors.
    By using this software you agree to the terms of the associated
    Analog Devices Software License Agreement.
    
    *****************************************************************************/
    
    #include "AD5940.H"
    #include <stdio.h>
    #include "string.h"
    #include "math.h"
    #include "Impedance.h"
    
    /* Default LPDAC resolution(2.5V internal reference). */
    #define DAC12BITVOLT_1LSB   (2200.0f/4095)  //mV
    #define DAC6BITVOLT_1LSB    (DAC12BITVOLT_1LSB*64)  //mV
    
    /* 
    Application configuration structure. Specified by user from template.
    The variables are usable in this whole application.
    It includes basic configuration for sequencer generator and application related parameters
    */
    AppIMPCfg_Type AppIMPCfg = 
    {
      .bParaChanged = bFALSE,
      .SeqStartAddr = 0,
      .MaxSeqLen = 0,
      
      .SeqStartAddrCal = 0,
      .MaxSeqLenCal = 0,
      
      .ImpODR = 20.0,           /* 20.0 Hz*/
      .NumOfData = -1,
      .SysClkFreq = 16000000.0,
      .WuptClkFreq = 32000.0,
      .AdcClkFreq = 16000000.0,
      .RcalVal = 10000.0,
      
      .DswitchSel = SWD_CE0,
      .PswitchSel = SWP_CE0,
      .NswitchSel = SWN_SE0LOAD,
      .TswitchSel = SWT_SE0LOAD,
      
      .PwrMod = AFEPWR_LP,
      
      .SensorCh0.LptiaRtiaSel = LPTIARTIA_4K, /* COnfigure RTIA */
      .SensorCh0.LpTiaRf = LPTIARF_1M,        /* Configure LPF resistor */
      .SensorCh0.LpTiaRl = LPTIARLOAD_100R,
      
      .HstiaRtiaSel = HSTIARTIA_1K,
      .ExcitBufGain = EXCITBUFGAIN_0P25,
      .HsDacGain = HSDACGAIN_0P2,
      .HsDacUpdateRate = 0x1B,
      .DacVoltPP = 300.0,
      .BiasVolt = -0.0f,
      
      .SinFreq = 100000.0, /* 1000Hz */
      
      .DftNum = DFTNUM_16384,
      .DftSrc = DFTSRC_SINC3,
      .HanWinEn = bTRUE,
      
      .AdcPgaGain = ADCPGA_1,
      .ADCSinc3Osr = ADCSINC3OSR_2,
      .ADCSinc2Osr = ADCSINC2OSR_22,
      
      .ADCAvgNum = ADCAVGNUM_16,
      
      .SweepCfg.SweepEn = bTRUE,
      .SweepCfg.SweepStart = 1000,
      .SweepCfg.SweepStop = 100000.0,
      .SweepCfg.SweepPoints = 101,
      .SweepCfg.SweepLog = bFALSE,
      .SweepCfg.SweepIndex = 0,
      
      .FifoThresh = 4,
      .IMPInited = bFALSE,
      .StopRequired = bFALSE,
    };
    
    /* Depending on frequency of Sin wave set optimum filter settings */
    AD5940Err AppIMPCheckFreq(float freq)
    {
      ADCFilterCfg_Type filter_cfg;
      DFTCfg_Type dft_cfg;
      HSDACCfg_Type hsdac_cfg;
      uint32_t WaitClks;
      ClksCalInfo_Type clks_cal;
      FreqParams_Type freq_params;
      uint32_t SeqCmdBuff[32];
      uint32_t SRAMAddr = 0;;
      /* Step 1: Check Frequency */
      freq_params = AD5940_GetFreqParameters(freq);
      
           if(freq < 0.51)
    	{
                /* Update HSDAC update rate */
        hsdac_cfg.ExcitBufGain =EXCITBUFGAIN_2;// AppIMPCfg.ExcitBufGain;
        hsdac_cfg.HsDacGain = HSDACGAIN_1;//AppIMPCfg.HsDacGain;
         hsdac_cfg.HsDacUpdateRate = 0x1B;
        AD5940_HSDacCfgS(&hsdac_cfg);
        AD5940_HSRTIACfgS(HSTIARTIA_40K);
        
        /*Update ADC rate */
        filter_cfg.ADCRate = ADCRATE_800KHZ;
        AppIMPCfg.AdcClkFreq = 16e6;
        
        /* Change clock to 16MHz oscillator */
        AD5940_HPModeEn(bFALSE);
    	}
            else if(freq < 5 )
    	{
           /* Update HSDAC update rate */
        hsdac_cfg.ExcitBufGain =EXCITBUFGAIN_2;// AppIMPCfg.ExcitBufGain;
        hsdac_cfg.HsDacGain = HSDACGAIN_1;//AppIMPCfg.HsDacGain;
        hsdac_cfg.HsDacUpdateRate = 0x1B;
        AD5940_HSDacCfgS(&hsdac_cfg);
        AD5940_HSRTIACfgS(HSTIARTIA_40K);
        
        /*Update ADC rate */
        filter_cfg.ADCRate = ADCRATE_800KHZ;
        AppIMPCfg.AdcClkFreq = 16e6;
        
        /* Change clock to 16MHz oscillator */
        AD5940_HPModeEn(bFALSE);
        
    	}else if(freq < 450)
    	{
           /* Update HSDAC update rate */
        hsdac_cfg.ExcitBufGain =AppIMPCfg.ExcitBufGain;
        hsdac_cfg.HsDacGain = AppIMPCfg.HsDacGain;  
        
         hsdac_cfg.HsDacUpdateRate = 0x1B;
        AD5940_HSDacCfgS(&hsdac_cfg);
        AD5940_HSRTIACfgS(HSTIARTIA_5K);
        
        /*Update ADC rate */
        filter_cfg.ADCRate = ADCRATE_800KHZ;
        AppIMPCfg.AdcClkFreq = 16e6;
        
        /* Change clock to 16MHz oscillator */
        AD5940_HPModeEn(bFALSE);
    	}
           else if(freq<80000)
           {
               /* Update HSDAC update rate */
        hsdac_cfg.ExcitBufGain =AppIMPCfg.ExcitBufGain;
        hsdac_cfg.HsDacGain = AppIMPCfg.HsDacGain;
        hsdac_cfg.HsDacUpdateRate = 0x1B;
        AD5940_HSDacCfgS(&hsdac_cfg);
        AD5940_HSRTIACfgS(HSTIARTIA_5K);
        
        /*Update ADC rate */
        filter_cfg.ADCRate = ADCRATE_800KHZ;
        AppIMPCfg.AdcClkFreq = 16e6;
        
        /* Change clock to 16MHz oscillator */
        AD5940_HPModeEn(bFALSE);
           }
            /* High power mode */
    	if(freq >= 80000)
    	{
    		  /* Update HSDAC update rate */
        hsdac_cfg.ExcitBufGain =AppIMPCfg.ExcitBufGain;
        hsdac_cfg.HsDacGain = AppIMPCfg.HsDacGain;
        hsdac_cfg.HsDacUpdateRate = 0x07;
        AD5940_HSDacCfgS(&hsdac_cfg);
        AD5940_HSRTIACfgS(HSTIARTIA_5K);
        
        /*Update ADC rate */
        filter_cfg.ADCRate = ADCRATE_1P6MHZ;
        AppIMPCfg.AdcClkFreq = 32e6;
        
        /* Change clock to 32MHz oscillator */
        AD5940_HPModeEn(bTRUE);
    	}
      
      /* Step 2: Adjust ADCFILTERCON and DFTCON to set optimumn SINC3, SINC2 and DFTNUM settings  */
      filter_cfg.ADCAvgNum = ADCAVGNUM_16;  /* Don't care because it's disabled */ 
      filter_cfg.ADCSinc2Osr = freq_params.ADCSinc2Osr;
      filter_cfg.ADCSinc3Osr = freq_params.ADCSinc3Osr;
      filter_cfg.BpSinc3 = bFALSE;
      filter_cfg.BpNotch = bTRUE;
      filter_cfg.Sinc2NotchEnable = bTRUE;
      dft_cfg.DftNum = freq_params.DftNum;
      dft_cfg.DftSrc = freq_params.DftSrc;
      dft_cfg.HanWinEn = AppIMPCfg.HanWinEn;
      AD5940_ADCFilterCfgS(&filter_cfg);
      AD5940_DFTCfgS(&dft_cfg);
      
      /* Step 3: Calculate clocks needed to get result to FIFO and update sequencer wait command */
      clks_cal.DataType = DATATYPE_DFT;
      clks_cal.DftSrc = freq_params.DftSrc;
      clks_cal.DataCount = 1L<<(freq_params.DftNum+2); /* 2^(DFTNUMBER+2) */
      clks_cal.ADCSinc2Osr = freq_params.ADCSinc2Osr;
      clks_cal.ADCSinc3Osr = freq_params.ADCSinc3Osr;
      clks_cal.ADCAvgNum = 0;
      clks_cal.RatioSys2AdcClk = AppIMPCfg.SysClkFreq/AppIMPCfg.AdcClkFreq;
      AD5940_ClksCalculate(&clks_cal, &WaitClks);		
    	
    	
    	  SRAMAddr = AppIMPCfg.MeasureSeqInfo.SeqRamAddr + AppIMPCfg.SeqWaitAddr[0];
    	   
               SeqCmdBuff[0] =SEQ_WAIT(WaitClks/2);
               SeqCmdBuff[1] =SEQ_WAIT(WaitClks/2);
          
    		AD5940_SEQCmdWrite(SRAMAddr, SeqCmdBuff, 2);
    		
    		SRAMAddr = AppIMPCfg.MeasureSeqInfo.SeqRamAddr + AppIMPCfg.SeqWaitAddr[1];
    		  
               SeqCmdBuff[0] =SEQ_WAIT(WaitClks/2);
               SeqCmdBuff[1] =SEQ_WAIT(WaitClks/2);
    
    		AD5940_SEQCmdWrite(SRAMAddr, SeqCmdBuff, 2);
                    
                    SRAMAddr = AppIMPCfg.MeasureSeqInfo.SeqRamAddr + AppIMPCfg.SeqWaitAddr[2];
    		  
               SeqCmdBuff[0] =SEQ_WAIT(WaitClks/2);
               SeqCmdBuff[1] =SEQ_WAIT(WaitClks/2);
    
    		AD5940_SEQCmdWrite(SRAMAddr, SeqCmdBuff, 2);
    
     
      return AD5940ERR_OK;
    }
    
    /**
    This function is provided for upper controllers that want to change 
    application parameters specially for user defined parameters.
    */
    int32_t AppIMPGetCfg(void *pCfg)
    {
      if(pCfg)
      {
        *(AppIMPCfg_Type**)pCfg = &AppIMPCfg;
        return AD5940ERR_OK;
      }
      return AD5940ERR_PARA;
    }
    
    int32_t AppIMPCtrl(uint32_t Command, void *pPara)
    {
      
      switch (Command)
      {
      case IMPCTRL_START:
        {
          WUPTCfg_Type wupt_cfg;
          
          if(AD5940_WakeUp(10) > 10)  /* Wakup AFE by read register, read 10 times at most */
            return AD5940ERR_WAKEUP;  /* Wakeup Failed */
          if(AppIMPCfg.IMPInited == bFALSE)
            return AD5940ERR_APPERROR;
          /* Start it */
          wupt_cfg.WuptEn = bTRUE;
          wupt_cfg.WuptEndSeq = WUPTENDSEQ_A;
          wupt_cfg.WuptOrder[0] = SEQID_0;
          wupt_cfg.SeqxSleepTime[SEQID_0] = 4;
          wupt_cfg.SeqxWakeupTime[SEQID_0] = (uint32_t)(AppIMPCfg.WuptClkFreq/AppIMPCfg.ImpODR)-4;
          AD5940_WUPTCfg(&wupt_cfg);
          
          AppIMPCfg.FifoDataCount = 0;  /* restart */
          break;
        }
      case IMPCTRL_STOPNOW:
        {
          if(AD5940_WakeUp(10) > 10)  /* Wakup AFE by read register, read 10 times at most */
            return AD5940ERR_WAKEUP;  /* Wakeup Failed */
          /* Start Wupt right now */
          AD5940_WUPTCtrl(bFALSE);
          AD5940_WUPTCtrl(bFALSE);  /* @todo is it sure this will stop Wupt? */
          break;
        }
      case IMPCTRL_STOPSYNC:
        {
          AppIMPCfg.StopRequired = bTRUE;
          break;
        }
      case IMPCTRL_GETFREQ:
        {
          if(pPara == 0)
            return AD5940ERR_PARA;
          if(AppIMPCfg.SweepCfg.SweepEn == bTRUE)
            *(float*)pPara = AppIMPCfg.FreqofData;
          else
            *(float*)pPara = AppIMPCfg.SinFreq;
        }
        break;
      case IMPCTRL_SHUTDOWN:
        {
          AppIMPCtrl(IMPCTRL_STOPNOW, 0);  /* Stop the measurment if it's running. */
          /* Turn off LPloop related blocks which are not controlled automatically by hibernate operation */
          AFERefCfg_Type aferef_cfg;
          LPLoopCfg_Type lploop_cfg;
          memset(&aferef_cfg, 0, sizeof(aferef_cfg));
          AD5940_REFCfgS(&aferef_cfg);
          memset(&lploop_cfg, 0, sizeof(lploop_cfg));
          AD5940_LPLoopCfgS(&lploop_cfg);
          AD5940_EnterSleepS();  /* Enter Hibernate */
        }
        break;
      default:
        break;
      }
      return AD5940ERR_OK;
    }
    
    /* generated code snnipet */
    float AppIMPGetCurrFreq(void)
    {
      if(AppIMPCfg.SweepCfg.SweepEn == bTRUE)
        return AppIMPCfg.FreqofData;
      else
        return AppIMPCfg.SinFreq;
    }
    
    /* Application initialization */
    static AD5940Err AppIMPSeqCfgGen(void)
    {
      AD5940Err error = AD5940ERR_OK;
      const uint32_t *pSeqCmd;
      uint32_t SeqLen;
      AFERefCfg_Type aferef_cfg;
      HSLoopCfg_Type HsLoopCfg;
      LPLoopCfg_Type lploop_cfg;
      DSPCfg_Type dsp_cfg;
      float sin_freq;
      
      /* Start sequence generator here */
      AD5940_SEQGenCtrl(bTRUE);
      
      AD5940_AFECtrlS(AFECTRL_ALL, bFALSE);  /* Init all to disable state */
      
      aferef_cfg.HpBandgapEn = bTRUE;
      aferef_cfg.Hp1V1BuffEn = bTRUE;
      aferef_cfg.Hp1V8BuffEn = bTRUE;
      aferef_cfg.Disc1V1Cap = bFALSE;
      aferef_cfg.Disc1V8Cap = bFALSE;
      aferef_cfg.Hp1V8ThemBuff = bFALSE;
      aferef_cfg.Hp1V8Ilimit = bFALSE;
      aferef_cfg.Lp1V1BuffEn = bFALSE;
      aferef_cfg.Lp1V8BuffEn = bFALSE;
      aferef_cfg.LpBandgapEn = bTRUE;
      aferef_cfg.LpRefBufEn = bTRUE;
      aferef_cfg.LpRefBoostEn = bFALSE;
      AD5940_REFCfgS(&aferef_cfg);	
      
      lploop_cfg.LpDacCfg.LpdacSel = LPDAC0;
      lploop_cfg.LpDacCfg.LpDacSrc = LPDACSRC_MMR;
      lploop_cfg.LpDacCfg.LpDacSW = LPDACSW_VBIAS2LPPA|LPDACSW_VBIAS2PIN|LPDACSW_VZERO2LPTIA|LPDACSW_VZERO2PIN;
      lploop_cfg.LpDacCfg.LpDacVzeroMux = LPDACVZERO_6BIT;
      lploop_cfg.LpDacCfg.LpDacVbiasMux = LPDACVBIAS_12BIT;
      lploop_cfg.LpDacCfg.LpDacRef = LPDACREF_2P5;
      lploop_cfg.LpDacCfg.DataRst = bFALSE;
      lploop_cfg.LpDacCfg.PowerEn = bTRUE;
      lploop_cfg.LpDacCfg.DacData6Bit = (uint32_t)((AppIMPCfg.SensorCh0.Vzero-200)/DAC6BITVOLT_1LSB);
      lploop_cfg.LpDacCfg.DacData12Bit =(int32_t)((AppIMPCfg.SensorCh0.SensorBias)/DAC12BITVOLT_1LSB) + lploop_cfg.LpDacCfg.DacData6Bit*64;
      if(lploop_cfg.LpDacCfg.DacData12Bit>lploop_cfg.LpDacCfg.DacData6Bit*64)
        lploop_cfg.LpDacCfg.DacData12Bit--;
      lploop_cfg.LpAmpCfg.LpAmpSel = LPAMP0;
      lploop_cfg.LpAmpCfg.LpAmpPwrMod = LPAMPPWR_NORM;
      lploop_cfg.LpAmpCfg.LpPaPwrEn = bTRUE;
      lploop_cfg.LpAmpCfg.LpTiaPwrEn = bTRUE;
      lploop_cfg.LpAmpCfg.LpTiaRf = AppIMPCfg.SensorCh0.LpTiaRf;
      lploop_cfg.LpAmpCfg.LpTiaRload = AppIMPCfg.SensorCh0.LpTiaRl;
      lploop_cfg.LpAmpCfg.LpTiaRtia = AppIMPCfg.SensorCh0.LptiaRtiaSel;
      lploop_cfg.LpAmpCfg.LpTiaSW = LPTIASW(5)|LPTIASW(2)|LPTIASW(4)|LPTIASW(12)|LPTIASW(13); 
      
      AD5940_LPLoopCfgS(&lploop_cfg);
      
      HsLoopCfg.HsDacCfg.ExcitBufGain = AppIMPCfg.ExcitBufGain;
      HsLoopCfg.HsDacCfg.HsDacGain = AppIMPCfg.HsDacGain;
      HsLoopCfg.HsDacCfg.HsDacUpdateRate = AppIMPCfg.HsDacUpdateRate;
      
      HsLoopCfg.HsTiaCfg.DiodeClose = bFALSE;
      HsLoopCfg.HsTiaCfg.HstiaBias = HSTIABIAS_1P1;
      HsLoopCfg.HsTiaCfg.HstiaCtia = 31; /* 31pF + 2pF */
      HsLoopCfg.HsTiaCfg.HstiaDeRload = HSTIADERLOAD_OPEN;
      HsLoopCfg.HsTiaCfg.HstiaDeRtia = HSTIADERTIA_OPEN;
      HsLoopCfg.HsTiaCfg.HstiaRtiaSel = AppIMPCfg.HstiaRtiaSel;
      
      HsLoopCfg.SWMatCfg.Dswitch = SWD_OPEN;
      HsLoopCfg.SWMatCfg.Pswitch = SWP_OPEN;
      HsLoopCfg.SWMatCfg.Nswitch = SWN_OPEN;
      HsLoopCfg.SWMatCfg.Tswitch = SWT_OPEN;
      
      HsLoopCfg.WgCfg.WgType = WGTYPE_SIN;
      HsLoopCfg.WgCfg.GainCalEn = bTRUE;
      HsLoopCfg.WgCfg.OffsetCalEn = bTRUE;
      if(AppIMPCfg.SweepCfg.SweepEn == bTRUE)
      {
        AppIMPCfg.FreqofData = AppIMPCfg.SweepCfg.SweepStart;
        AppIMPCfg.SweepCurrFreq = AppIMPCfg.SweepCfg.SweepStart;
        AD5940_SweepNext(&AppIMPCfg.SweepCfg, &AppIMPCfg.SweepNextFreq);
        sin_freq = AppIMPCfg.SweepCurrFreq;
      }
      else
      {
        sin_freq = AppIMPCfg.SinFreq;
        AppIMPCfg.FreqofData = sin_freq;
      }
      HsLoopCfg.WgCfg.SinCfg.SinFreqWord = AD5940_WGFreqWordCal(sin_freq, AppIMPCfg.SysClkFreq);
      HsLoopCfg.WgCfg.SinCfg.SinAmplitudeWord = (uint32_t)(AppIMPCfg.DacVoltPP/800.0f*2047 + 0.5f);
      HsLoopCfg.WgCfg.SinCfg.SinOffsetWord = 0;
      HsLoopCfg.WgCfg.SinCfg.SinPhaseWord = 0;
      AD5940_HSLoopCfgS(&HsLoopCfg);
      
      dsp_cfg.ADCBaseCfg.ADCMuxN = ADCMUXN_HSTIA_N;
      dsp_cfg.ADCBaseCfg.ADCMuxP = ADCMUXP_HSTIA_P;
      dsp_cfg.ADCBaseCfg.ADCPga = AppIMPCfg.AdcPgaGain;
      
      memset(&dsp_cfg.ADCDigCompCfg, 0, sizeof(dsp_cfg.ADCDigCompCfg));
      
      dsp_cfg.ADCFilterCfg.ADCAvgNum = AppIMPCfg.ADCAvgNum;
      dsp_cfg.ADCFilterCfg.ADCRate = ADCRATE_800KHZ;	/* @todo what does this parameter decide */
      dsp_cfg.ADCFilterCfg.ADCSinc2Osr = AppIMPCfg.ADCSinc2Osr;
      dsp_cfg.ADCFilterCfg.ADCSinc3Osr = AppIMPCfg.ADCSinc3Osr;
      dsp_cfg.ADCFilterCfg.BpNotch = bTRUE;
      dsp_cfg.ADCFilterCfg.BpSinc3 = bFALSE;
      dsp_cfg.ADCFilterCfg.Sinc2NotchEnable = bTRUE;
      dsp_cfg.DftCfg.DftNum = AppIMPCfg.DftNum;
      dsp_cfg.DftCfg.DftSrc = AppIMPCfg.DftSrc;
      dsp_cfg.DftCfg.HanWinEn = AppIMPCfg.HanWinEn;
      
      memset(&dsp_cfg.StatCfg, 0, sizeof(dsp_cfg.StatCfg));
      AD5940_DSPCfgS(&dsp_cfg);
      
      /* Enable all of them. They are automatically turned off during hibernate mode to save power */
      if(AppIMPCfg.BiasVolt == 0.0f)
        AD5940_AFECtrlS(AFECTRL_HSTIAPWR|AFECTRL_INAMPPWR|AFECTRL_EXTBUFPWR|\
          AFECTRL_WG|AFECTRL_DACREFPWR|AFECTRL_HSDACPWR|\
            AFECTRL_SINC2NOTCH, bTRUE);
      else
        AD5940_AFECtrlS(AFECTRL_HSTIAPWR|AFECTRL_INAMPPWR|AFECTRL_EXTBUFPWR|\
          AFECTRL_WG|AFECTRL_DACREFPWR|AFECTRL_HSDACPWR|\
            AFECTRL_SINC2NOTCH|AFECTRL_DCBUFPWR, bTRUE);
      /* Sequence end. */
      AD5940_SEQGenInsert(SEQ_STOP()); /* Add one extral command to disable sequencer for initialization sequence because we only want it to run one time. */
      
      /* Stop here */
      error = AD5940_SEQGenFetchSeq(&pSeqCmd, &SeqLen);
      AD5940_SEQGenCtrl(bFALSE); /* Stop seuqncer generator */
      if(error == AD5940ERR_OK)
      {
        AppIMPCfg.InitSeqInfo.SeqId = SEQID_1;
        AppIMPCfg.InitSeqInfo.SeqRamAddr = AppIMPCfg.SeqStartAddr;
        AppIMPCfg.InitSeqInfo.pSeqCmd = pSeqCmd;
        AppIMPCfg.InitSeqInfo.SeqLen = SeqLen;
        /* Write command to SRAM */
        AD5940_SEQCmdWrite(AppIMPCfg.InitSeqInfo.SeqRamAddr, pSeqCmd, SeqLen);
      }
      else
        return error; /* Error */
      return AD5940ERR_OK;
    }
    
    
    static AD5940Err AppIMPSeqMeasureGen(void)
    {
      AD5940Err error = AD5940ERR_OK;
      const uint32_t *pSeqCmd;
      uint32_t SeqLen;
      
      uint32_t WaitClks;
      SWMatrixCfg_Type sw_cfg;
      ClksCalInfo_Type clks_cal;
      LPAmpCfg_Type LpAmpCfg;
      
      /* Calculate number of clocks to get data to FIFO */
      clks_cal.DataType = DATATYPE_DFT;
      clks_cal.DftSrc = AppIMPCfg.DftSrc;
      clks_cal.DataCount = 1L<<(AppIMPCfg.DftNum+2); /* 2^(DFTNUMBER+2) */
      clks_cal.ADCSinc2Osr = AppIMPCfg.ADCSinc2Osr;
      clks_cal.ADCSinc3Osr = AppIMPCfg.ADCSinc3Osr;
      clks_cal.ADCAvgNum = AppIMPCfg.ADCAvgNum;
      clks_cal.RatioSys2AdcClk = AppIMPCfg.SysClkFreq/AppIMPCfg.AdcClkFreq;
      AD5940_ClksCalculate(&clks_cal, &WaitClks);
      
      /* Start Sequence Generator */
      AD5940_SEQGenCtrl(bTRUE);
      AD5940_SEQGpioCtrlS(AGPIO_Pin2); /* Set GPIO1, clear others that under control */
      AD5940_SEQGenInsert(SEQ_WAIT(16*250));  /* @todo wait 250us? */
      
      /* Disconnect SE0 from LPTIA*/
      LpAmpCfg.LpAmpSel = LPAMP0;
      LpAmpCfg.LpAmpPwrMod = LPAMPPWR_NORM;
      LpAmpCfg.LpPaPwrEn = bTRUE;
      LpAmpCfg.LpTiaPwrEn = bTRUE;
      LpAmpCfg.LpTiaRf = AppIMPCfg.SensorCh0.LpTiaRf;
      LpAmpCfg.LpTiaRload = AppIMPCfg.SensorCh0.LpTiaRl;
      LpAmpCfg.LpTiaRtia = LPTIARTIA_OPEN; /* Disconnect Rtia to avoid RC filter discharge */
      LpAmpCfg.LpTiaSW = LPTIASW(7)|LPTIASW(4)|LPTIASW(12)|LPTIASW(13); 
      AD5940_LPAMPCfgS(&LpAmpCfg);
      /* Sensor + Rload Measurement */
      sw_cfg.Dswitch = AppIMPCfg.DswitchSel;
      sw_cfg.Pswitch = AppIMPCfg.PswitchSel;
      sw_cfg.Nswitch = AppIMPCfg.NswitchSel;
      sw_cfg.Tswitch = SWT_TRTIA|AppIMPCfg.TswitchSel;
      AD5940_SWMatrixCfgS(&sw_cfg);
      
      AD5940_AFECtrlS(AFECTRL_HSTIAPWR|AFECTRL_INAMPPWR|AFECTRL_EXTBUFPWR|\
        AFECTRL_WG|AFECTRL_DACREFPWR|AFECTRL_HSDACPWR|\
          AFECTRL_SINC2NOTCH, bTRUE);
        
      AD5940_AFECtrlS(AFECTRL_ADCPWR|AFECTRL_SINC2NOTCH, bTRUE);  /* Enable Waveform generator */
      //delay for signal settling DFT_WAIT
      AD5940_SEQGenInsert(SEQ_WAIT(16*10));
      AD5940_AFECtrlS(AFECTRL_ADCCNV|AFECTRL_DFT, bTRUE);  /* Start ADC convert and DFT */
      AD5940_SEQGenFetchSeq(NULL, &AppIMPCfg.SeqWaitAddr[0]); /* Record the start address of the next command. */
    
      AD5940_SEQGenInsert(SEQ_WAIT(WaitClks/2));
       AD5940_SEQGenInsert(SEQ_WAIT(WaitClks/2));
      //wait for first data ready
      AD5940_AFECtrlS(AFECTRL_HSTIAPWR|AFECTRL_INAMPPWR|AFECTRL_EXTBUFPWR|\
        AFECTRL_WG|AFECTRL_DACREFPWR|AFECTRL_HSDACPWR|\
          AFECTRL_SINC2NOTCH|AFECTRL_DFT|AFECTRL_ADCCNV, bFALSE);
      
      /* RLOAD Measurement */
      sw_cfg.Dswitch = SWD_SE0;
      sw_cfg.Pswitch = SWP_SE0;
      sw_cfg.Nswitch = SWN_SE0LOAD;
      sw_cfg.Tswitch = SWT_SE0LOAD|SWT_TRTIA;
      AD5940_SWMatrixCfgS(&sw_cfg);
      AD5940_AFECtrlS(AFECTRL_HSTIAPWR|AFECTRL_INAMPPWR|AFECTRL_EXTBUFPWR|\
        AFECTRL_WG|AFECTRL_DACREFPWR|AFECTRL_HSDACPWR|AFECTRL_SINC2NOTCH, bTRUE);
      AD5940_SEQGenInsert(SEQ_WAIT(16*10));  //delay for signal settling DFT_WAIT
      AD5940_AFECtrlS(AFECTRL_ADCCNV|AFECTRL_DFT, bTRUE);  /* Start ADC convert and DFT */
      AD5940_SEQGenFetchSeq(NULL, &AppIMPCfg.SeqWaitAddr[1]); /* Record the start address of the next command. */
    
      AD5940_SEQGenInsert(SEQ_WAIT(WaitClks/2));
       AD5940_SEQGenInsert(SEQ_WAIT(WaitClks/2));
      AD5940_AFECtrlS(AFECTRL_HSTIAPWR|AFECTRL_INAMPPWR|AFECTRL_EXTBUFPWR|\
        AFECTRL_WG|AFECTRL_DACREFPWR|AFECTRL_HSDACPWR|\
          AFECTRL_SINC2NOTCH|AFECTRL_ADCCNV, bFALSE);
      
      /* RCAL Measurement */
      sw_cfg.Dswitch = SWD_RCAL0;
      sw_cfg.Pswitch = SWP_RCAL0;
      sw_cfg.Nswitch = SWN_RCAL1;
      sw_cfg.Tswitch = SWT_RCAL1|SWT_TRTIA;
      AD5940_SWMatrixCfgS(&sw_cfg);
      /* Reconnect LP loop */
      LpAmpCfg.LpTiaRtia = AppIMPCfg.SensorCh0.LptiaRtiaSel; /* Reconnect Rtia */
      LpAmpCfg.LpTiaSW = LPTIASW(5)|LPTIASW(2)|LPTIASW(8)|LPTIASW(12)|LPTIASW(13); 
      AD5940_LPAMPCfgS(&LpAmpCfg);
      
      AD5940_AFECtrlS(AFECTRL_HSTIAPWR|AFECTRL_INAMPPWR|AFECTRL_EXTBUFPWR|\
        AFECTRL_WG|AFECTRL_DACREFPWR|AFECTRL_HSDACPWR|AFECTRL_SINC2NOTCH, bTRUE);
      AD5940_SEQGenInsert(SEQ_WAIT(16*10));  //delay for signal settling DFT_WAIT
      AD5940_AFECtrlS(AFECTRL_ADCCNV|AFECTRL_DFT/*|AFECTRL_SINC2NOTCH*/, bTRUE);  /* Start ADC convert and DFT */
     AD5940_SEQGenFetchSeq(NULL, &AppIMPCfg.SeqWaitAddr[2]); /* Record the start address of the next command. */
    
      AD5940_SEQGenInsert(SEQ_WAIT(WaitClks/2));
       AD5940_SEQGenInsert(SEQ_WAIT(WaitClks/2));
      AD5940_AFECtrlS(AFECTRL_ADCCNV|AFECTRL_DFT|AFECTRL_WG|AFECTRL_ADCPWR, bFALSE);  /* Stop ADC convert and DFT */
      AD5940_AFECtrlS(AFECTRL_HSTIAPWR|AFECTRL_INAMPPWR|AFECTRL_EXTBUFPWR|\
        AFECTRL_WG|AFECTRL_DACREFPWR|AFECTRL_HSDACPWR|\
          AFECTRL_SINC2NOTCH, bFALSE);
      
      
      AD5940_SEQGpioCtrlS(0); /* Clr GPIO1 */
      
      sw_cfg.Dswitch = SWD_OPEN;
      sw_cfg.Pswitch = SWP_OPEN;
      sw_cfg.Nswitch = SWN_OPEN;
      sw_cfg.Tswitch = SWT_OPEN;
      AD5940_SWMatrixCfgS(&sw_cfg);
      
      //AD5940_EnterSleepS();/* Goto hibernate */
      
      /* Sequence end. */
      error = AD5940_SEQGenFetchSeq(&pSeqCmd, &SeqLen);
      AD5940_SEQGenCtrl(bFALSE); /* Stop seuqncer generator */
      
      if(error == AD5940ERR_OK)
      {
        AppIMPCfg.MeasureSeqInfo.SeqId = SEQID_0;
        AppIMPCfg.MeasureSeqInfo.SeqRamAddr = AppIMPCfg.InitSeqInfo.SeqRamAddr + AppIMPCfg.InitSeqInfo.SeqLen ;
        AppIMPCfg.MeasureSeqInfo.pSeqCmd = pSeqCmd;
        AppIMPCfg.MeasureSeqInfo.SeqLen = SeqLen;
        /* Write command to SRAM */
        AD5940_SEQCmdWrite(AppIMPCfg.MeasureSeqInfo.SeqRamAddr, pSeqCmd, SeqLen);
      }
      else
        return error; /* Error */
      return AD5940ERR_OK;
    }
    
    
    /* This function provide application initialize. It can also enable Wupt that will automatically trigger sequence. Or it can configure  */
    int32_t AppIMPInit(uint32_t *pBuffer, uint32_t BufferSize)
    {
      AD5940Err error = AD5940ERR_OK;  
      SEQCfg_Type seq_cfg;
      FIFOCfg_Type fifo_cfg;
      
      if(AD5940_WakeUp(10) > 10)  /* Wakup AFE by read register, read 10 times at most */
        return AD5940ERR_WAKEUP;  /* Wakeup Failed */
      
      /* Configure sequencer and stop it */
      seq_cfg.SeqMemSize = SEQMEMSIZE_2KB;  /* 2kB SRAM is used for sequencer, others for data FIFO */
      seq_cfg.SeqBreakEn = bFALSE;
      seq_cfg.SeqIgnoreEn = bTRUE;
      seq_cfg.SeqCntCRCClr = bTRUE;
      seq_cfg.SeqEnable = bFALSE;
      seq_cfg.SeqWrTimer = 0;
      AD5940_SEQCfg(&seq_cfg);
      
      /* Reconfigure FIFO */
      AD5940_FIFOCtrlS(FIFOSRC_DFT, bFALSE);									/* Disable FIFO firstly */
      fifo_cfg.FIFOEn = bTRUE;
      fifo_cfg.FIFOMode = FIFOMODE_FIFO;
      fifo_cfg.FIFOSize = FIFOSIZE_4KB;                       /* 4kB for FIFO, The reset 2kB for sequencer */
      fifo_cfg.FIFOSrc = FIFOSRC_DFT;
      fifo_cfg.FIFOThresh = AppIMPCfg.FifoThresh;              /* DFT result. One pair for RCAL, another for Rz. One DFT result have real part and imaginary part */
      AD5940_FIFOCfg(&fifo_cfg);
      AD5940_INTCClrFlag(AFEINTSRC_ALLINT);
      
      /* Start sequence generator */
      /* Initialize sequencer generator */
      if((AppIMPCfg.IMPInited == bFALSE)||\
        (AppIMPCfg.bParaChanged == bTRUE))
      {
        if(pBuffer == 0)  return AD5940ERR_PARA;
        if(BufferSize == 0) return AD5940ERR_PARA;   
        AD5940_SEQGenInit(pBuffer, BufferSize);
        
        /* Generate initialize sequence */
        error = AppIMPSeqCfgGen(); /* Application initialization sequence using either MCU or sequencer */
        if(error != AD5940ERR_OK) return error;
        
        /* Generate measurement sequence */
        error = AppIMPSeqMeasureGen();
        if(error != AD5940ERR_OK) return error;
        
        AppIMPCfg.bParaChanged = bFALSE; /* Clear this flag as we already implemented the new configuration */
      }
      
      /* Initialization sequencer  */
      AppIMPCfg.InitSeqInfo.WriteSRAM = bFALSE;
      AD5940_SEQInfoCfg(&AppIMPCfg.InitSeqInfo);
      seq_cfg.SeqEnable = bTRUE;
      AD5940_SEQCfg(&seq_cfg);  /* Enable sequencer */
      AD5940_SEQMmrTrig(AppIMPCfg.InitSeqInfo.SeqId);
      while(AD5940_INTCTestFlag(AFEINTC_1, AFEINTSRC_ENDSEQ) == bFALSE);
      
      /* Measurment sequence  */
      AppIMPCfg.MeasureSeqInfo.WriteSRAM = bFALSE;
      AD5940_SEQInfoCfg(&AppIMPCfg.MeasureSeqInfo);
      
      AppIMPCheckFreq(AppIMPCfg.FreqofData);
      
      seq_cfg.SeqEnable = bTRUE;
      AD5940_SEQCfg(&seq_cfg);  /* Enable sequencer, and wait for trigger */
      AD5940_ClrMCUIntFlag();   /* Clear interrupt flag generated before */
      
      AD5940_AFEPwrBW(AppIMPCfg.PwrMod, AFEBW_250KHZ);
      
      AppIMPCfg.IMPInited = bTRUE;  /* IMP application has been initialized. */
      return AD5940ERR_OK;
    }
    
    /* Modify registers when AFE wakeup */
    int32_t AppIMPRegModify(int32_t * const pData, uint32_t *pDataCount)
    {
      if(AppIMPCfg.NumOfData > 0)
      {
        AppIMPCfg.FifoDataCount += *pDataCount/4;
        if(AppIMPCfg.FifoDataCount >= AppIMPCfg.NumOfData)
        {
          AD5940_WUPTCtrl(bFALSE);
          return AD5940ERR_OK;
        }
      }
      if(AppIMPCfg.StopRequired == bTRUE)
      {
        AD5940_WUPTCtrl(bFALSE);
        return AD5940ERR_OK;
      }
      if(AppIMPCfg.SweepCfg.SweepEn) /* Need to set new frequency and set power mode */
      {
        AD5940_WGFreqCtrlS(AppIMPCfg.SweepNextFreq, AppIMPCfg.SysClkFreq);
        AppIMPCheckFreq(AppIMPCfg.SweepNextFreq);
      }
      return AD5940ERR_OK;
    }
    
    /* 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/6;
      
      fImpPol_Type * const pOut = (fImpPol_Type*)pData;
      iImpCar_Type * pSrcData = (iImpCar_Type*)pData;
      
      *pDataCount = 0;
      
      DataCount = (DataCount/6)*6;/* We expect Rz+Rload, Rload and RCAL 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++)
      {
    //    if(1)
    //    {
    //      fImpCar_Type DftRcal, DftRzRload, DftRload, temp1, temp2, res;
    //      fImpCar_Type DftConst1 = {1.0f, 0};
    //      /*
    //      The sign of DFT Image result is added '-1' by hardware. Fix it below.
    //      */
    //      DftRzRload.Real = pSrcData->Real;
    //      DftRzRload.Image = -pSrcData->Image;
    //      pSrcData++;
    //      DftRload.Real = pSrcData->Real;
    //      DftRload.Image = -pSrcData->Image;
    //      pSrcData++;
    //      DftRcal.Real = pSrcData->Real;
    //      DftRcal.Image = -pSrcData->Image;
    //      pSrcData++;
    //      /**
    //      Rz = RloadRz - Rload
    //      RloadRz = DftRcal/DftRzRload*RCAL;
    //      Rload = DftRcal/DftRload*RCAL;
    //      Rz = RloadRz - Rload = 
    //      (1/DftRzRload - 1/DftRload)*DftRcal*RCAL;
    //      where RCAL is the RCAL resistor value in Ohm.
    //      */
    //      //temp1 = 1/DftRzRload;
    //      //temp2 = 1/DftRload;
    //      temp1 = AD5940_ComplexDivFloat(&DftConst1, &DftRzRload); 
    //      temp2 = AD5940_ComplexDivFloat(&DftConst1, &DftRload); 
    //      res = AD5940_ComplexSubFloat(&temp1, &temp2);
    //      res = AD5940_ComplexMulFloat(&res, &DftRcal);
    //      pOut[i].Magnitude = AD5940_ComplexMag(&res)*AppIMPCfg.RcalVal;
    //      pOut[i].Phase = AD5940_ComplexPhase(&res);
    //    }
    //    else
        {
          iImpCar_Type *pDftRcal, *pDftRzRload, *pDftRload;
          
          pDftRzRload = pSrcData++;
          pDftRload = pSrcData++;
          pDftRcal = pSrcData++;
          
          float RzRloadMag, RzRloadPhase;
          float RloadMag, RloadPhase;
          float RzMag,RzPhase;
          float RcalMag, RcalPhase;
          float RzReal, RzImage;
          
          RzReal = pDftRload->Real - pDftRzRload->Real;
          RzImage = pDftRload->Image - pDftRzRload->Image;
          
          RzRloadMag = sqrt((float)pDftRzRload->Real*pDftRzRload->Real+(float)pDftRzRload->Image*pDftRzRload->Image);
          RzRloadPhase = atan2(-pDftRzRload->Image,pDftRzRload->Real);
          RcalMag = sqrt((float)pDftRcal->Real*pDftRcal->Real+(float)pDftRcal->Image*pDftRcal->Image);
          RcalPhase = atan2(-pDftRcal->Image,pDftRcal->Real);
          RzMag = sqrt((float)RzReal*RzReal+(float)RzImage*RzImage);
          RzPhase = atan2(-RzImage,RzReal);
          RloadMag = sqrt((float)pDftRload->Real*pDftRload->Real+(float)pDftRload->Image*pDftRload->Image);
          RloadPhase = atan2(-pDftRload->Image,pDftRload->Real);
          
          RzMag = (AppIMPCfg.RcalVal*RcalMag*RzMag)/(RzRloadMag*RloadMag);
          RzPhase = -(RcalPhase + RzPhase - RloadPhase - RzRloadPhase);
          // RzPhase = (RcalPhase + RzPhase - RloadPhase - RzRloadPhase);
          
          
          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;
    }
    
    /**
    
    */
    int32_t AppIMPISR(void *pBuff, uint32_t *pCount)
    {
      uint32_t BuffCount;
      uint32_t FifoCnt;
      BuffCount = *pCount;
      
      *pCount = 0;
      
      if(AD5940_WakeUp(10) > 10)  /* Wakup AFE by read register, read 10 times at most */
        return AD5940ERR_WAKEUP;  /* Wakeup Failed */
      AD5940_SleepKeyCtrlS(SLPKEY_LOCK);  /* Prohibit AFE to enter sleep mode. */
      
      if(AD5940_INTCTestFlag(AFEINTC_0, AFEINTSRC_DATAFIFOTHRESH) == bTRUE)
      {
        /* Now there should be 4 data in FIFO */
        FifoCnt = (AD5940_FIFOGetCnt()/6)*6;
        
        if(FifoCnt > BuffCount)
        {
          ///@todo buffer is limited.
        }
        AD5940_FIFORd((uint32_t *)pBuff, FifoCnt);
        AD5940_INTCClrFlag(AFEINTSRC_DATAFIFOTHRESH);
        AppIMPRegModify(pBuff, &FifoCnt);   /* If there is need to do AFE re-configure, do it here when AFE is in active state */
        //AD5940_EnterSleepS(); /* Manually put AFE back to hibernate mode. This operation only takes effect when register value is ACTIVE previously */
        AD5940_SleepKeyCtrlS(SLPKEY_UNLOCK);  /* Allow AFE to enter sleep mode. */
        /* Process data */ 
        AppIMPDataProcess((int32_t*)pBuff,&FifoCnt); 
        *pCount = FifoCnt;
        return 0;
      }
      
      return 0;
    } 
    
    
    

  • Nice! And where do I call the AppIMPCheckFreq(float freq) function? I supposed it is on the AD5940Main.c, right? But where?

  • 0
    •  Analog Employees 
    on Oct 6, 2021 1:12 PM in reply to Oliveira.C.

    Hi,

    It is not called in main, but in impedance.c itself.

    Search for the function in this code itself.