amperometric

Question

I'd like to modify the sequencer code in AmperometricMeasurement.c to leave the DAC running at its VL2 value forever. I understand that it's possible to comment out the 2nd to last line of the sequence to make the AFE sample forever, but the DAC doesn't stay at its VL2 level. I also tried deleting the wait statement (in the 3rd to last line of the sequence, see attached), but that had no effect, the DAC output is still eventually brought low. How does one modify the sequence to have the DAC be set to VL2 forever?

LiamR · Accepted Answer

Hi, 
 
 What you need to do is to change the line to disable the waveform generator and keep the ADC sampling enabled, for example by changing 0x80020EF0 to 0x80020FF0 in the second last line of the sequence. 
 Make sure the disabling of the waveform generator happens at a time when VL2 is being output by the DAC. 
 
 Another way to do it is write the VL2 to the DAC directly and change the waveform generator type to direct write to DAC (AFE_WG_CFG:TYPE_SEL = 0), if for some reason disable the waveform generator doesn’t suit. 
 
 Also be mindful of the AFE power down function: 
 
 /* AFE Power Down */ 
 if (ADI_AFE_SUCCESS != adi_AFE_PowerDown(hAfeDevice)) 
 { 
 FAIL("adi_AFE_PowerDown"); 
 }

Regards, 
 Liam