AD5940_EDA Firmware

Hi there,

We are just testing the AD5940 for EDA measurements. Now we are trying to understand all the parameters within the chip and all its functionality. We have a question related to the main configuration for the EDA firmware example. Initially, the code is:

void AD5940EDAStructInit(void)
{
  AppEDACfg_Type *pCfg;
  
  AppEDAGetCfg(&pCfg);
  pCfg->MaxSeqLen = 512;
  
  pCfg->LfoscClkFreq = 32000;             /* Don't do LFOSC calibration now. We assume the default LFOSC is trimmed. */
  pCfg->RtiaAutoScaleEnable = bTRUE;     /* We manually select resistor value. */
  pCfg->LptiaRtiaSel = LPTIARTIA_120K;    
  pCfg->SinAmplitude = 1100*3/4;          /* Set excitation voltage to 0.75 times of full range. */
  pCfg->SinFreq = 100.0f;                 
  pCfg->SampleFreq = 400.0f;              /* Do not change sample frequency unless you know how it works. */
  pCfg->EDAODR = 4.0f;                    /* ODR decides how freuquently to start the engine to measure impedance. */
  pCfg->FifoThresh = 4;                   /* The minimum threshold value is 4, and should always be 4*N, where N is 1,2,3... */
}

If we change the SinFreq (frequency of the sine wave used for excitation) and we divide it by 5 (so we have a 20Hz excitation sin wave), do we have to divide by the same factor the "pCfg->SampleFreq"? We have seen that this last parameter is used to wait for the DFT conversion, but we do not know if we have to change it as well as the SinFreq.

thank you!