4 Replies Latest reply on Nov 22, 2012 9:57 AM by user_78878863

    ADC problem

    rajendra.prasad

       Hi to all,

         

                    I am  doing work on blood glucose measurement with PSoC 3 , in that a current from test strip taken and converted to voltage and calibration if that interms of glucose.but as a sample i am giving current from IDAC component that is converted to voltage. this voltage i am giving to ADC to display it in volts , here upto PGA i am getting voltage but after giving to ADC i am getting Garbage value output on LCD.i think the problem here is with ADC ,can anyone help me regarding this.

         

      thanks

         

      PRP

        • 1. Re: ADC problem
          user_14586677

          Post your project, and what is the signal look like, voltage level, before you process

             

          with PSOC ?

             

           

             

          Regards, Dana.

          • 2. Re: ADC problem
            ramnath.r.k

             hi,

               

            So, you have a DC Signal from IDAC(Correct me if my assumption is wrong) and you put that in to ADC. Consider the following suggestions,

               

            1. Make sure you choose the most optimised range in the ADC, preamplify the signal above the noise floor and choose the resolution as such. 

               

            2. Make sure you wait for the end of conversion, before taking the value out of the ADC_DEC_SAMP_REG.(Use IsEndConversion() API)

               

            3. If you are sure that the above mentioned points are satisfied for ADC, then the problem shall most probably be with the LCD Code that has been written.

               

             

               

            Regards,

               

            Rahulram

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            • 3. Re: ADC problem
              rajendra.prasad

               hi Rahulram i have checked that , but i havent resolved my problem

              • 4. Re: ADC problem
                user_78878863

                How do you define 'garbage values'? Does it just display random values? If you constrain the output of the IDAC, do you get what you expect?

                   

                Did you debug your code (breakpoint after you retrieve the values from the ADC) to see whether the problem is in the ADC or in the display code?

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