5 Replies Latest reply on Feb 16, 2012 2:33 PM by user_1377889

    Chattering bits with different resolution of ADC

    content.librarian

       Hello, I have tested my programs with different resolution of ADC in 8MHz (According to the datasheet, this is the maximum dataclock for the module). The ADC values are then trasmitted to a virtual terminal through UART. It is interesting that the ADC has significant chattering bit in ADC resolution which are higher than 8bit.

         

      These are some examples that I get when the analogue input are connected to ground:

         

      8Bit (In Hex Form)

         

      0001

         

      0002

         

      0001

         

      0002

         

      0001

         

      0001

         

      0002

         

      0001

         

      ...

         

      ...

         

       

         

      9bit or higher resolution (In Hex Form)

         

      0001

         

      0002

         

      0002

         

      0001

         

      0002

         

      0001

         

      0002

         

      0001

         

      ...

         

      ...

         

      0102

         

      ...

         

      ...

         

      0101

         

      ...

         

      ...

         

       

         

       

         

      Are these mainly caused by the 8-bit PWM cycles in the ADC module? Please correct me if I have made any misconceptions.

         

      Thank you very much.

         

       

         

      Thank you very much.