Differential mode ADC - wrong readings

JaRa_1183061 · ‎Oct 10, 2021

Hi

I am using the ADC_DelSig in differential mode. I am interested in sampling the voltage between two metal electrodes in electrolysis (between 100 mV to 1 V). The ADC voltage is fluctuating a lot – most of the time giving random values. My question is therefore, what could be wrong?

Here is my setup for the ADC.

Pin_1 is on metal 1 (positive) and pin_2 is on metal 2 (negative). I am using the ADC_DelSig_1_CountsTo_mVolts(ADC_DelSig_1_GetResult32()) function.

Thanks -

Len_CONSULTRON · ‎Oct 13, 2021

JaRa,

As Vasanth suggested, it is always useful when testing out your design to apply a known voltage on the electrodes. This will allow you to verify the quality of your design before using it on a unknown test environment ( ie: electrolysis bath.)

Using a series of "known" voltages is also a good method of calibrating your system before putting it into use.

Len
"Engineering is an Art. The Art of Compromise."

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Differential mode ADC - wrong readings

Differential mode ADC - wrong readings

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