PSoC™ 5, 3 & 1 Forum Discussions

[JaRa_1183061]

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 - 

[Vasanth]

Hi, 

One doubt, are the absolute voltages on the terminals are within the working range of the device ?(between VDDA and VSSA ?) Is the setup working properly if you try to measure any other known voltage?

Best Regards,
Vasanth

[Len_CONSULTRON · Accepted solution]

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.