5 Replies Latest reply on Mar 16, 2016 5:44 AM by user_1377889

    Using the Del-Sig-ADC to measure voltage Problem with calibration

    p.g

      Hi,

         

      I am trying to measure a voltage over a resistor to get it´s value, my problem is that i can not calibrate the ADC to measure the correct voltage.

         

      I tried to measure the offset manually as recommended in the AN84783 "Accurate Measurement Using PSoC 3 and PSoC 5LP Delta - Sigma ADCs" that gave me a value of 42942, which makes absolutely no sense, then i tried to calculate two known points into a function to eliminate offset and gain error, but that did not help either.

         

      After that i tried to implement the two-point-calibration from the ADC-VoltageInp Example project, that does not help.

         

      I think i did something basically wrong, could someone please take a look at my project and tell me where i screwed up?

         

      I am using the CY8C5888LTI-LP097 Prototyping Board, and Creator 3.3, attached for you is a picture of my circuit that is on the breadboard now. I need to switch between the reference resistors to measure a bigger range of resistors. I measured the internal resistances from the PSoC and added them to the values, thats why they look so strange.

         

      If you need further information please let me know, I hope i have translated all necessary comments in the SW into english.

         

      Thanks for your help, Greetings, Patrick