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Cyclic Voltammetry - Initial ramp voltage, ADUCM355

Category: Software

Hi,

I have used Cyclic Voltammetry code successfully with different sensors but now one of my applications requires maintaining the initial voltage for some time before the ramp starts.

In order to do that I use a timer and a wait loop just after this part of the code

lploop_cfg.LpDacCfg.LpdacSel = LPDAC0;
lploop_cfg.LpDacCfg.DacData6Bit = (uint32_t)((AppRAMPCfg.VzeroStart-200)/DAC6BITVOLT_1LSB);;
lploop_cfg.LpDacCfg.DacData12Bit = (int32_t)((AppRAMPCfg.RampStartVolt)/DAC12BITVOLT_1LSB) + lploop_cfg.LpDacCfg.DacData6Bit*64;;
lploop_cfg.LpDacCfg.DataRst = bFALSE;
lploop_cfg.LpDacCfg.LpDacSW = LPDACSW_VBIAS2LPPA/*|LPDACSW_VBIAS2PIN*/ | LPDACSW_VZERO2LPTIA/*|LPDACSW_VZERO2PIN*/;
lploop_cfg.LpDacCfg.LpDacRef = LPDACREF_2P5;
lploop_cfg.LpDacCfg.LpDacSrc = LPDACSRC_MMR;
lploop_cfg.LpDacCfg.LpDacVbiasMux = LPDACVBIAS_12BIT; /* Step Vbias. Use 12bit DAC ouput */
lploop_cfg.LpDacCfg.LpDacVzeroMux = LPDACVZERO_6BIT; /* Base is Vzero. Use 6 bit DAC ouput */
lploop_cfg.LpDacCfg.PowerEn = bTRUE;
AD5940_LPLoopCfgS(&lploop_cfg);

which is located in static AD5940Err AppRAMPSeqInitGen(void) function.

However, during the wait loop, the initial voltage does not appear between RE and SE. Only once the ramp starts the voltage change is detected.

Could you please try to shed some light on this? I am not sure why voltage does not appear here. Could you please advice on how to set initial voltage for some time lenght?

Thank you.