Unable to get proper results in Cyclic Voltammetry using AD5940

Hi,

Kindly refer to the help panel by hovering over the parameter of interest:

Scan rate = dV/dt = (RampPeakVolt - RampStartVolt)/RampDuration         (when VzeroStart = VzeroPeak)

Units are as mentioned in the comments in code.

Thank you. I will try them and get back to you.

How can I get the stimulus Voltage for plotting the graph?

Stimulus voltage can be monitored on the pins (VCE0 - VSE0).

If using CV example code on IDE, you may give VCE0 and VSE0 as inputs to ADC mux , to get the stimulus voltage.

Hello

I have tried doing the CV experiment in Sensor Pal as well as the CV example code on github but am still not getting the proper graph for this .I have plotted the V vs I graph with the values obtained from the example code and obtained a graph similar to the one I got in sensorPal.

I am expecting a proper 'duck shaped' graph as mentioned in the picture I have shared before. Please guide me on additional steps or anything that I may be missing out on.

  /* Configure ramp signal parameters */
  pRampCfg->RampStartVolt =  -200.0f;           /* -1V */
  pRampCfg->RampPeakVolt = +600.0f;             /* +1V */
  pRampCfg->VzeroStart = 1300.0f;               /* 1.3V */
  pRampCfg->VzeroPeak = 1300.0f;                /* 1.3V */
  pRampCfg->StepNumber = 800;                   /* Total steps. Equals to ADC sample number */
  pRampCfg->RampDuration = 24*1000;             /* X * 1000, where x is total duration of ramp signal. Unit is ms. */
  pRampCfg->SampleDelay = 7.0f;                 /* 7ms. Time between update DAC and ADC sample. Unit is ms. */
  pRampCfg->LPTIARtiaSel = LPTIARTIA_1K;        /* Maximum current decides RTIA value */
	pRampCfg->LPTIARloadSel = LPTIARLOAD_SHORT;
	pRampCfg->AdcPgaGain = ADCPGA_1P5;

These are the ramp settings that I have used. Can I contact you by mail so that we can have a call about this?

Hi,

Check out the excitation Voltage at RE0 w.r..t. GND in graph below for the below settings:

pRampCfg->RampStartVolt =  -900.0f;           /* -1V */

  pRampCfg->RampPeakVolt = +1100.0f;           /* +1V */

  pRampCfg->VzeroStart = 1300.0f;               /* 1.3V */

  pRampCfg->VzeroPeak = 1300.0f;                /* 1.3V */

  pRampCfg->StepNumber = 200;                   /* Total steps. Equals to ADC sample number */

  pRampCfg->RampDuration = 400;            /* X * 1000, where x is total duration of ramp signal. Unit is ms. */

  pRampCfg->SampleDelay = 1.0f;                 /* 7ms. Time between update DAC and ADC sample. Unit is ms. */

  pRampCfg->LPTIARtiaSel = LPTIARTIA_4K;       /* Maximum current decides RTIA value */

You may monitor the excitation signal on both your setups (potentiostat and AD5940 eval board) to see the differences and configure AD5940 accordingly.