How to Increase Sampling Rate For The EVAL-AD5940BIOZ Board (Impedance Measurements)

Question

Hello, 
 I was wondering how the sampling rate for the EVAL-AD5940BIOZ board can be changed or is there a buffer limit to the number of samples that can be taken?. I am currently using the IAR software program and SerialTerm Capture to record the outputting data. I ran a sample test with a 1kOhm resistor for 1 second and I was able to record 184 lines of data. I am aiming to increase the sampling rate to 2,000 samples/second. I have already changed certain lines of code given by Github to run the example project, I will include those changes down below. Any suggestions or thoughts would be greatly appreciated. Thank you!.

Akila · Accepted Answer

Hi, Since Bioz2Wire code uses sequences (which run only at 32KHz), max allowed ODR is 5HZ only. Max of 10HZ can be achieved when measuring only ADC raw data. Below is the code modified for this: /****************************************************************************** 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 "BIOZ-2Wire.h" /** * @note This example is modified from BIOZ example. This one is for 2-wire impedance measuremnt. * The default pins used are CE0 and AIN2. The differnce with BIOZ is that the body voltage * Measurment is replaced with excitation voltage measurment and it's only measured once. */ /* 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 */ AppBIOZCfg_Type AppBIOZCfg = { .bParaChanged = bFALSE, .SeqStartAddr = 0, .MaxSeqLen = 0, .SeqStartAddrCal = 0, .MaxSeqLenCal = 0, .ReDoRtiaCal = bFALSE, .SysClkFreq = 16000000.0, .WuptClkFreq = 32000.0, .AdcClkFreq = 16000000.0, .BIOZODR = 20.0, /* 20.0 Hz*/ .NumOfData = -1, .RcalVal = 10000.0, /* 10kOhm */ .PwrMod = AFEPWR_LP, .HstiaRtiaSel = HSTIARTIA_10K, .CtiaSel = 16, .ExcitBufGain = EXCITBUFGAIN_2, .HsDacGain = HSDACGAIN_1, .HsDacUpdateRate = 7, .DacVoltPP = 600.0, .SinFreq = 50000.0, /* 5000Hz */ .ADCPgaGain = ADCPGA_1P5, .ADCSinc3Osr = ADCSINC3OSR_2, .ADCSinc2Osr = ADCSINC2OSR_22, .DftNum = DFTNUM_8192, .DftSrc = DFTSRC_SINC3, .HanWinEn = bTRUE, .SweepCfg.SweepEn = bFALSE, .SweepCfg.SweepStart = 10000, .SweepCfg.SweepStop = 150000.0, .SweepCfg.SweepPoints = 100, .SweepCfg.SweepLog = bTRUE, .SweepCfg.SweepIndex = 0, .FifoThresh = 4, /* Must be 4 when SweepEn = bTRUE*/ .BIOZInited = bFALSE, .StopRequired = bFALSE, }; /** This function is provided for upper controllers that want to change application parameters specially for user defined parameters. */ AD5940Err AppBIOZGetCfg(void *pCfg) { if(pCfg){ *(AppBIOZCfg_Type**)pCfg = &AppBIOZCfg; return AD5940ERR_OK; } return AD5940ERR_PARA; } AD5940Err AppBIOZCtrl(int32_t BcmCtrl, void *pPara) { switch (BcmCtrl) { case BIOZCTRL_START: { WUPTCfg_Type wupt_cfg; if(AD5940_WakeUp(10) > 10) /* Wakeup AFE by read register, read 10 times at most */ return AD5940ERR_WAKEUP; /* Wakeup Failed */ if(AppBIOZCfg.BIOZInited == bFALSE) return AD5940ERR_APPERROR; /* Start the wakeup timer */ wupt_cfg.WuptEn = bTRUE; wupt_cfg.WuptEndSeq = WUPTENDSEQ_A; wupt_cfg.WuptOrder[0] = SEQID_0; wupt_cfg.SeqxSleepTime[SEQID_0] = (uint32_t)(AppBIOZCfg.WuptClkFreq/AppBIOZCfg.BIOZODR)-2-1; wupt_cfg.SeqxWakeupTime[SEQID_0] = 1; /* The minimum value is 1. Do not set it to zero. Set it to 1 will spend 2 32kHz clock. */ AD5940_WUPTCfg(&wupt_cfg); AppBIOZCfg.FifoDataCount = 0; /* restart */ #ifdef ADI_DEBUG ADI_Print("BIOZ Start... "); #endif break; } case BIOZCTRL_STOPNOW: { if(AD5940_WakeUp(10) > 10) /* Wakeup AFE by read register, read 10 times at most */ return AD5940ERR_WAKEUP; /* Wakeup Failed */ /* Stop Wupt right now */ AD5940_WUPTCtrl(bFALSE); AD5940_WUPTCtrl(bFALSE); #ifdef ADI_DEBUG ADI_Print("BIOZ Stop Now... "); #endif break; } case BIOZCTRL_STOPSYNC: { #ifdef ADI_DEBUG ADI_Print("BIOZ Stop SYNC... "); #endif AppBIOZCfg.StopRequired = bTRUE; break; } case BIOZCTRL_GETFREQ: if(pPara) { if(AppBIOZCfg.SweepCfg.SweepEn == bTRUE) *(float*)pPara = AppBIOZCfg.FreqofData; else *(float*)pPara = AppBIOZCfg.SinFreq; } break; case BIOZCTRL_SHUTDOWN: { AppBIOZCtrl(BIOZCTRL_STOPNOW, 0); /* Stop the measurment if it's running. */ /* Turn off LPloop related blocks which are not controlled automatically by sleep operation */ AFERefCfg_Type aferef_cfg; LPLoopCfg_Type lp_loop; memset(&aferef_cfg, 0, sizeof(aferef_cfg)); AD5940_REFCfgS(&aferef_cfg); memset(&lp_loop, 0, sizeof(lp_loop)); AD5940_LPLoopCfgS(&lp_loop); AD5940_EnterSleepS(); /* Enter Hibernate */ #ifdef ADI_DEBUG ADI_Print("BIOZ Shut down... "); #endif } break; default: break; } return AD5940ERR_OK; } /* Generate init sequence */ static AD5940Err AppBIOZSeqCfgGen(void) { AD5940Err error = AD5940ERR_OK; uint32_t const *pSeqCmd; uint32_t SeqLen; AFERefCfg_Type aferef_cfg; HSLoopCfg_Type hs_loop; DSPCfg_Type dsp_cfg; float sin_freq; /* Start sequence generator here */ AD5940_SEQGenCtrl(bTRUE); 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; /* LP reference control - turn off them to save powr*/ aferef_cfg.LpBandgapEn = bTRUE; aferef_cfg.LpRefBufEn = bTRUE; aferef_cfg.LpRefBoostEn = bFALSE; AD5940_REFCfgS(&aferef_cfg); hs_loop.HsDacCfg.ExcitBufGain = AppBIOZCfg.ExcitBufGain; hs_loop.HsDacCfg.HsDacGain = AppBIOZCfg.HsDacGain; hs_loop.HsDacCfg.HsDacUpdateRate = AppBIOZCfg.HsDacUpdateRate; hs_loop.HsTiaCfg.DiodeClose = bFALSE; hs_loop.HsTiaCfg.HstiaBias = HSTIABIAS_1P1; hs_loop.HsTiaCfg.HstiaCtia = AppBIOZCfg.CtiaSel; /* 31pF + 2pF */ hs_loop.HsTiaCfg.HstiaDeRload = HSTIADERLOAD_OPEN; hs_loop.HsTiaCfg.HstiaDeRtia = HSTIADERTIA_OPEN; hs_loop.HsTiaCfg.HstiaRtiaSel = AppBIOZCfg.HstiaRtiaSel; hs_loop.SWMatCfg.Dswitch = SWD_OPEN; hs_loop.SWMatCfg.Pswitch = SWP_PL|SWP_PL2; hs_loop.SWMatCfg.Nswitch = SWN_NL|SWN_NL2; hs_loop.SWMatCfg.Tswitch = SWT_TRTIA; hs_loop.WgCfg.WgType = WGTYPE_SIN; hs_loop.WgCfg.GainCalEn = bFALSE; hs_loop.WgCfg.OffsetCalEn = bFALSE; if(AppBIOZCfg.SweepCfg.SweepEn == bTRUE) { AppBIOZCfg.SweepCfg.SweepIndex = 0; AppBIOZCfg.FreqofData = AppBIOZCfg.SweepCfg.SweepStart; AppBIOZCfg.SweepCurrFreq = AppBIOZCfg.SweepCfg.SweepStart; AD5940_SweepNext(&AppBIOZCfg.SweepCfg, &AppBIOZCfg.SweepNextFreq); sin_freq = AppBIOZCfg.SweepCurrFreq; } else { sin_freq = AppBIOZCfg.SinFreq; AppBIOZCfg.FreqofData = sin_freq; } hs_loop.WgCfg.SinCfg.SinFreqWord = AD5940_WGFreqWordCal(sin_freq, AppBIOZCfg.SysClkFreq); hs_loop.WgCfg.SinCfg.SinAmplitudeWord = (uint32_t)(AppBIOZCfg.DacVoltPP/800.0f*2047 + 0.5f); hs_loop.WgCfg.SinCfg.SinOffsetWord = 0; hs_loop.WgCfg.SinCfg.SinPhaseWord = 0; AD5940_HSLoopCfgS(&hs_loop); dsp_cfg.ADCBaseCfg.ADCMuxN = ADCMUXN_HSTIA_N; dsp_cfg.ADCBaseCfg.ADCMuxP = ADCMUXP_HSTIA_P; dsp_cfg.ADCBaseCfg.ADCPga = AppBIOZCfg.ADCPgaGain; memset(&dsp_cfg.ADCDigCompCfg, 0, sizeof(dsp_cfg.ADCDigCompCfg)); //dsp_cfg.ADCFilterCfg.ADCAvgNum = ADCAVGNUM_16; /* Don't care becase it's disabled */ dsp_cfg.ADCFilterCfg.ADCRate = ADCRATE_800KHZ; /* Tell filter block clock rate of ADC*/ dsp_cfg.ADCFilterCfg.ADCSinc2Osr = AppBIOZCfg.ADCSinc2Osr; dsp_cfg.ADCFilterCfg.ADCSinc3Osr = AppBIOZCfg.ADCSinc3Osr; dsp_cfg.ADCFilterCfg.BpSinc3 = bTRUE;//bFALSE; dsp_cfg.ADCFilterCfg.BpNotch = bTRUE; dsp_cfg.ADCFilterCfg.Sinc2NotchEnable = bTRUE; //dsp_cfg.DftCfg.DftNum = AppBIOZCfg.DftNum; //dsp_cfg.DftCfg.DftSrc = AppBIOZCfg.DftSrc; //dsp_cfg.DftCfg.HanWinEn = AppBIOZCfg.HanWinEn; memset(&dsp_cfg.StatCfg, 0, sizeof(dsp_cfg.StatCfg)); /* Don't care about Statistic */ AD5940_DSPCfgS(&dsp_cfg); /* Enable all of them. They are automatically turned off during hibernate mode to save power */ AD5940_AFECtrlS(AFECTRL_HPREFPWR|AFECTRL_HSTIAPWR|AFECTRL_INAMPPWR|AFECTRL_EXTBUFPWR|\ AFECTRL_DACREFPWR|AFECTRL_HSDACPWR|\ AFECTRL_SINC2NOTCH, bTRUE); AD5940_SEQGpioCtrlS(0/*AGPIO_Pin6|AGPIO_Pin5|AGPIO_Pin1*/); //GP6->endSeq, GP5 -> AD8233=OFF, GP1->RLD=OFF . /* 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) { AppBIOZCfg.InitSeqInfo.SeqId = SEQID_1; AppBIOZCfg.InitSeqInfo.SeqRamAddr = AppBIOZCfg.SeqStartAddr; AppBIOZCfg.InitSeqInfo.pSeqCmd = pSeqCmd; AppBIOZCfg.InitSeqInfo.SeqLen = SeqLen; /* Write command to SRAM */ AD5940_SEQCmdWrite(AppBIOZCfg.InitSeqInfo.SeqRamAddr, pSeqCmd, SeqLen); } else return error; /* Error */ return AD5940ERR_OK; } static AD5940Err AppBIOZSeqMeasureGen(void) { AD5940Err error = AD5940ERR_OK; uint32_t const *pSeqCmd; uint32_t SeqLen; uint32_t WaitClks; SWMatrixCfg_Type sw_cfg; ClksCalInfo_Type clks_cal; clks_cal.DataType = DATATYPE_ADCRAW;//DATATYPE_DFT; //clks_cal.DftSrc = AppBIOZCfg.DftSrc; clks_cal.DataCount = 1L<<(AppBIOZCfg.DftNum+2); /* 2^(DFTNUMBER+2) */ clks_cal.ADCSinc2Osr = AppBIOZCfg.ADCSinc2Osr; clks_cal.ADCSinc3Osr = AppBIOZCfg.ADCSinc3Osr; clks_cal.ADCAvgNum = 0; clks_cal.RatioSys2AdcClk = AppBIOZCfg.SysClkFreq/AppBIOZCfg.AdcClkFreq; AD5940_ClksCalculate(&clks_cal, &WaitClks); /* Start sequence generator here */ AD5940_SEQGenCtrl(bTRUE); AD5940_SEQGpioCtrlS(AGPIO_Pin1/*|AGPIO_Pin5|AGPIO_Pin1*/);//GP6->endSeq, GP5 -> AD8233=OFF, GP1->RLD=OFF . /* Configure switch matrix to connect the sensor */ sw_cfg.Dswitch = AppBIOZCfg.DswitchSel; sw_cfg.Pswitch = AppBIOZCfg.PswitchSel; sw_cfg.Nswitch = AppBIOZCfg.NswitchSel; sw_cfg.Tswitch = AppBIOZCfg.TswitchSel|SWT_TRTIA; AD5940_SWMatrixCfgS(&sw_cfg); AD5940_SEQGenInsert(SEQ_WAIT(16*250)); /* Step 1: Measure Current */ AD5940_ADCMuxCfgS(ADCMUXP_HSTIA_P, ADCMUXN_HSTIA_N); AD5940_AFECtrlS(AFECTRL_WG|AFECTRL_ADCPWR, bTRUE); /* Enable Waveform generator, ADC power */ AD5940_SEQGenInsert(SEQ_WAIT(16*50)); AD5940_AFECtrlS(AFECTRL_ADCCNV|AFECTRL_DFT, bTRUE); /* Start ADC convert and DFT */ AD5940_SEQGenInsert(SEQ_WAIT(WaitClks)); /* wait for first data ready */ AD5940_SEQGenInsert(SEQ_WAIT(1)); AD5940_AFECtrlS(AFECTRL_ADCCNV|AFECTRL_DFT|AFECTRL_WG|AFECTRL_ADCPWR, bFALSE); /* Stop ADC convert and DFT */ /* Step 2: Measure Voltage */ AD5940_ADCMuxCfgS(ADCMUXP_VCE0, ADCMUXN_N_NODE); AD5940_AFECtrlS(AFECTRL_WG|AFECTRL_ADCPWR, bTRUE); /* Enable Waveform generator, ADC power */ AD5940_SEQGenInsert(SEQ_WAIT(16*50)); AD5940_AFECtrlS(AFECTRL_ADCCNV|AFECTRL_DFT, bTRUE); /* Start ADC convert and DFT */ AD5940_SEQGenInsert(SEQ_WAIT(WaitClks)); /* wait for first data ready */ AD5940_SEQGenInsert(SEQ_WAIT(1)); AD5940_AFECtrlS(AFECTRL_ADCCNV|AFECTRL_DFT|AFECTRL_WG|AFECTRL_ADCPWR, bFALSE); /* Stop ADC convert and DFT */ sw_cfg.Dswitch = SWD_OPEN; sw_cfg.Pswitch = SWP_PL|SWP_PL2; sw_cfg.Nswitch = SWN_NL|SWN_NL2; sw_cfg.Tswitch = SWT_TRTIA; AD5940_SWMatrixCfgS(&sw_cfg); /* Float switches */ AD5940_SEQGpioCtrlS(0/*AGPIO_Pin6|AGPIO_Pin5|AGPIO_Pin1*/); //GP6->endSeq, GP5 -> AD8233=OFF, GP1->RLD=OFF . AD5940_EnterSleepS();/* Goto hibernate */ /* Sequence end. */ error = AD5940_SEQGenFetchSeq(&pSeqCmd, &SeqLen); AD5940_SEQGenCtrl(bFALSE); /* Stop seuqncer generator */ AppBIOZCfg.MeasSeqCycleCount = AD5940_SEQCycleTime(); AppBIOZCfg.MaxODR = 1/((( AppBIOZCfg.MeasSeqCycleCount + 10) / 32.0)* 1E-6) ; //If Sysclk is16MHz if(AppBIOZCfg.BIOZODR > AppBIOZCfg.MaxODR) { /* We have requested a sampling rate that cannot be achieved with the time it takes to acquire a sample.*/ AppBIOZCfg.BIOZODR = AppBIOZCfg.MaxODR; } if(error == AD5940ERR_OK) { AppBIOZCfg.MeasureSeqInfo.SeqId = SEQID_0; AppBIOZCfg.MeasureSeqInfo.SeqRamAddr = AppBIOZCfg.InitSeqInfo.SeqRamAddr + AppBIOZCfg.InitSeqInfo.SeqLen ; AppBIOZCfg.MeasureSeqInfo.pSeqCmd = pSeqCmd; AppBIOZCfg.MeasureSeqInfo.SeqLen = SeqLen; /* Write command to SRAM */ AD5940_SEQCmdWrite(AppBIOZCfg.MeasureSeqInfo.SeqRamAddr, pSeqCmd, SeqLen); } else return error; /* Error */ return AD5940ERR_OK; } static AD5940Err AppBIOZRtiaCal(void) { HSRTIACal_Type hsrtia_cal; FreqParams_Type freq_params; if(AppBIOZCfg.SweepCfg.SweepEn == bTRUE) { hsrtia_cal.fFreq = AppBIOZCfg.SweepCfg.SweepStart; freq_params = AD5940_GetFreqParameters(AppBIOZCfg.SweepCfg.SweepStart); } else { hsrtia_cal.fFreq = AppBIOZCfg.SinFreq; freq_params = AD5940_GetFreqParameters(AppBIOZCfg.SinFreq); } if(freq_params.HighPwrMode == bTRUE) hsrtia_cal.AdcClkFreq = 32e6; else hsrtia_cal.AdcClkFreq = 16e6; hsrtia_cal.ADCSinc2Osr = freq_params.ADCSinc2Osr; hsrtia_cal.ADCSinc3Osr = freq_params.ADCSinc3Osr; hsrtia_cal.DftCfg.DftNum = freq_params.DftNum; hsrtia_cal.DftCfg.DftSrc = freq_params.DftSrc; hsrtia_cal.bPolarResult = bTRUE; /* We need magnitude and phase here */ hsrtia_cal.DftCfg.HanWinEn = AppBIOZCfg.HanWinEn; hsrtia_cal.fRcal= AppBIOZCfg.RcalVal; hsrtia_cal.HsTiaCfg.DiodeClose = bFALSE; hsrtia_cal.HsTiaCfg.HstiaBias = HSTIABIAS_1P1; hsrtia_cal.HsTiaCfg.HstiaCtia = AppBIOZCfg.CtiaSel; hsrtia_cal.HsTiaCfg.HstiaDeRload = HSTIADERLOAD_OPEN; hsrtia_cal.HsTiaCfg.HstiaDeRtia = HSTIADERTIA_OPEN; hsrtia_cal.HsTiaCfg.HstiaRtiaSel = AppBIOZCfg.HstiaRtiaSel; hsrtia_cal.SysClkFreq = AppBIOZCfg.SysClkFreq; if(AppBIOZCfg.SweepCfg.SweepEn == bTRUE) { uint32_t i; AppBIOZCfg.SweepCfg.SweepIndex = 0; /* Reset index */ for(i=0;i 10) /* Wakeup 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 = bFALSE; seq_cfg.SeqCntCRCClr = bTRUE; seq_cfg.SeqEnable = bFALSE; seq_cfg.SeqWrTimer = 0; AD5940_SEQCfg(&seq_cfg); /* Do RTIA calibration */ if((AppBIOZCfg.ReDoRtiaCal == bTRUE) || \ AppBIOZCfg.BIOZInited == bFALSE) /* Do calibration on the first initializaion */ { AppBIOZRtiaCal(); AppBIOZCfg.ReDoRtiaCal = bFALSE; } /* 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 = AppBIOZCfg.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((AppBIOZCfg.BIOZInited == bFALSE)||\ (AppBIOZCfg.bParaChanged == bTRUE)) { if(pBuffer == 0) return AD5940ERR_PARA; if(BufferSize == 0) return AD5940ERR_PARA; AD5940_SEQGenInit(pBuffer, BufferSize); /* Generate initialize sequence */ error = AppBIOZSeqCfgGen(); /* Application initialization sequence using either MCU or sequencer */ if(error != AD5940ERR_OK) return error; /* Generate measurement sequence */ error = AppBIOZSeqMeasureGen(); if(error != AD5940ERR_OK) return error; AppBIOZCfg.bParaChanged = bFALSE; /* Clear this flag as we already implemented the new configuration */ } /* Initialization sequencer */ AppBIOZCfg.InitSeqInfo.WriteSRAM = bFALSE; AD5940_SEQInfoCfg(&AppBIOZCfg.InitSeqInfo); seq_cfg.SeqEnable = bTRUE; AD5940_SEQCfg(&seq_cfg); /* Enable sequencer */ AD5940_SEQMmrTrig(AppBIOZCfg.InitSeqInfo.SeqId); while(AD5940_INTCTestFlag(AFEINTC_1, AFEINTSRC_ENDSEQ) == bFALSE); AD5940_INTCClrFlag(AFEINTSRC_ALLINT); /* Measurment sequence */ AppBIOZCfg.MeasureSeqInfo.WriteSRAM = bFALSE; AD5940_SEQInfoCfg(&AppBIOZCfg.MeasureSeqInfo); AppBIOZCheckFreq(AppBIOZCfg.FreqofData); seq_cfg.SeqEnable = bTRUE; AD5940_SEQCfg(&seq_cfg); /* Enable sequencer, and wait for trigger */ AD5940_ClrMCUIntFlag(); /* Clear interrupt flag generated before */ AppBIOZCfg.BIOZInited = bTRUE; /* BIOZ application has been initialized. */ return AD5940ERR_OK; } /* Depending on frequency of Sin wave set optimum filter settings */ AD5940Err AppBIOZCheckFreq(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[2]; uint32_t SRAMAddr = 0;; /* Step 1: Check Frequency */ freq_params = AD5940_GetFreqParameters(freq); /* Set power mode */ if(freq_params.HighPwrMode == bTRUE) { /* Update HSDAC update rate */ hsdac_cfg.ExcitBufGain = AppBIOZCfg.ExcitBufGain; hsdac_cfg.HsDacGain = AppBIOZCfg.HsDacGain; hsdac_cfg.HsDacUpdateRate = 0x7; AD5940_HSDacCfgS(&hsdac_cfg); /*Update ADC rate */ filter_cfg.ADCRate = ADCRATE_1P6MHZ; AppBIOZCfg.AdcClkFreq = 32e6; /* Change clock to 32MHz oscillator */ AD5940_HPModeEn(bTRUE); }else { /* Update HSDAC update rate */ hsdac_cfg.ExcitBufGain = AppBIOZCfg.ExcitBufGain; hsdac_cfg.HsDacGain = AppBIOZCfg.HsDacGain; hsdac_cfg.HsDacUpdateRate = 0x1B; AD5940_HSDacCfgS(&hsdac_cfg); /* Update ADC rate */ filter_cfg.ADCRate = ADCRATE_800KHZ; AppBIOZCfg.AdcClkFreq = 16e6; /* Change clock to 16MHz oscillator */ AD5940_HPModeEn(bFALSE); } /* 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 = AppBIOZCfg.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 = AppBIOZCfg.SysClkFreq/AppBIOZCfg.AdcClkFreq; AD5940_ClksCalculate(&clks_cal, &WaitClks); /* Maximum number of clocks is 0x3FFFFFFF. More are needed if the frequency is low */ if(WaitClks > 0x3FFFFFFF) { WaitClks /=2; SRAMAddr = AppBIOZCfg.MeasureSeqInfo.SeqRamAddr; SeqCmdBuff[0] = SEQ_WAIT(WaitClks); AD5940_SEQCmdWrite(SRAMAddr+11, SeqCmdBuff, 1); AD5940_SEQCmdWrite(SRAMAddr+12, SeqCmdBuff, 1); AD5940_SEQCmdWrite(SRAMAddr+18, SeqCmdBuff, 1); AD5940_SEQCmdWrite(SRAMAddr+19, SeqCmdBuff, 1); } else { SRAMAddr = AppBIOZCfg.MeasureSeqInfo.SeqRamAddr; SeqCmdBuff[0] = SEQ_WAIT(WaitClks); AD5940_SEQCmdWrite(SRAMAddr+11, SeqCmdBuff, 1); AD5940_SEQCmdWrite(SRAMAddr+18, SeqCmdBuff, 1); } return AD5940ERR_OK; } /* Modify registers when AFE wakeup */ static AD5940Err AppBIOZRegModify(int32_t * const pData, uint32_t *pDataCount) { if(AppBIOZCfg.NumOfData > 0) { AppBIOZCfg.FifoDataCount += *pDataCount/4; if(AppBIOZCfg.FifoDataCount >= AppBIOZCfg.NumOfData) { AD5940_WUPTCtrl(bFALSE); return AD5940ERR_OK; } } if(AppBIOZCfg.StopRequired == bTRUE) { AD5940_WUPTCtrl(bFALSE); return AD5940ERR_OK; } if(AppBIOZCfg.SweepCfg.SweepEn) /* Need to set new frequency and set power mode */ { AppBIOZCheckFreq(AppBIOZCfg.SweepNextFreq); AD5940_WGFreqCtrlS(AppBIOZCfg.SweepNextFreq, AppBIOZCfg.SysClkFreq); } return AD5940ERR_OK; } /* Depending on the data type, do appropriate data pre-process before return back to controller */ static AD5940Err AppBIOZDataProcess(int32_t * const pData, uint32_t *pDataCount) { uint32_t DataCount = *pDataCount; uint32_t ImpResCount = DataCount/4; fImpCar_Type * pOut = (fImpCar_Type*)pData; iImpCar_Type * pSrcData = (iImpCar_Type*)pData; *pDataCount = 0; DataCount = (DataCount/4)*4; /* One DFT result has two data in FIFO, real part and imaginary part. Each measurement has 2 DFT results, one for voltage measurement, one for current */ /* Convert DFT result to int32_t type */ for(uint32_t i=0; i 10) /* Wakeup AFE by read register, read 10 times at most */ return AD5940ERR_WAKEUP; /* Wakeup Failed */ AD5940_SleepKeyCtrlS(SLPKEY_LOCK); /* Don't enter hibernate */ *pCount = 0; if(AD5940_INTCTestFlag(AFEINTC_0, AFEINTSRC_DATAFIFOTHRESH) == bTRUE) { /* Now there should be 4 data in FIFO */ FifoCnt = (AD5940_FIFOGetCnt()/4)*4; AD5940_FIFORd((uint32_t *)pBuff, FifoCnt); AD5940_INTCClrFlag(AFEINTSRC_DATAFIFOTHRESH); AppBIOZRegModify(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 to save power. */ AD5940_SleepKeyCtrlS(SLPKEY_UNLOCK); /* Allow AFE to enter hibernate mode */ /* Process data */ AppBIOZDataProcess((int32_t*)pBuff,&FifoCnt); *pCount = FifoCnt; return 0; } return 0; } /** * @} */ For achieving 1000Hz, the code should be written without sequences.)

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How to Increase Sampling Rate For The EVAL-AD5940BIOZ Board (Impedance Measurements)