8 Replies Latest reply on Jan 31, 2014 2:12 PM by user_14586677

    Problem in ADC_SAR_Seq example project

    abhijit.kuvar

      DEVICE: CY8C5868AXI-LP035

         

      I am using PSoC Creator 3.0 for my design and I was interested in SAR ADC component. In the example project of ADC_SAR_Seq there is a project in which four on-board (evaluation kit) VDACs give input to 4-channel SAR ADC and example projects helps to demonstrate that ADC can properly convert those voltages. I have mainly two problems with this:

         

      1) I am using evaluation board. The Initial VDAC settings are 200 mV, 400 mV, 600 mV and 800 mV. The voltages, although, that are getting displayed on the LCD are 300, 600, 900 and 1200 mV respectively (readings of C1, C2, C3, C4). When I tried changing the VDAC settings to 300, 600, 900 and 1200, the voltages getting displayed on the screen are 450, 900, 1050 and 1800.

         

      So is there a scaling factor of 1.5 somewhere which I am missing? The example project, I suppose should not behave like this, because I haven't made any kind of alterations inside the project.

         

      2) When I faced above problem, I tried to replicate the exact project (with same pin numbers and configuration). I copied the exact same code from the project. When I tried to build it, it spewed out some errors that

         

      a) Analog teminal "vdac_ref" on ADC_SAR_SEQ_v1_10 is unconnected (even though I have internally bypassed vdac_ref)

         

      b) Analog terminal "AMuxHw_1.BoutTerm" on ADC_SAR_SEQ_v1_10 is unconnected.

         

      Can someone please explain what is happening here?