3 Replies Latest reply on Aug 1, 2011 2:44 AM by gautamd_

    Differential mode problem ADC_delsig Psoc 5 Kit-014



      I am trying to use the ADC_delsig on one of my Psoc 5  CY8C5588AXI-060 that come the Kit-014. The Single measurement works fine, but the Differential gives me the same result as the Single. I am giving 2.5 V to the Positive  input of the ADC_delsig and 1.3V to the Negative input of the ADC but the ADC always read 2.5V whatever is on the negative input.


      The thing is,  I am also using CAN in the same program to send the ADC result and display it on a LCD on an another controller. Maybe the CAN interfere with the ADC ? I doubt it is the case though..


      I have also a Psoc 3  CY8C3866AXI-040 that come with the Kit-001 and thne using the ADC_delsig code given in the examples that come with the Psoc creator, everything work fine , and I can read in Differential mode on this controller.


      I have attached my code to this post, Can anybody help me make this differential reqding work on my Psoc 5 CY8C5588AXI-060?


      Thank you very much,



        • 1. Re: Differential mode problem ADC_delsig Psoc 5 Kit-014

          I am sorry for the multiple post,I do not not how to delete them and the website did not allow me tu upload my files.

          • 2. Re: Differential mode problem ADC_delsig Psoc 5 Kit-014

            Ok I changed browser and it works now, the code was attached on the previous reply.


            Sorry about that

            • 3. Re: Differential mode problem ADC_delsig Psoc 5 Kit-014

              Hi Tim,




              I tested the project on CY8CKIT-001 usiung PSoC5 processor module.




              The following changes were made in the project.


              1) The Analog Pins were initially not connected to the ADC's Input terminals. The Square at the end of the pin and the ADC's terminal should coincide. Then the square will disappear indicating that the terminal is connected to the Analog pin.














              2) The ADC's Input range should be chosen appropriately. In this case if the differential voltage is 1.2V (2.5V - 1.3V), but the Input range was chosen as +/- 1.024 V. If the range is chosen as +/- 2.048V, then the input voltage will not violate the maximum Reference.




              With these changes and using a Char LCD component, I was able to see the correct reading which changes with change is the voltage as expected.


              There seems to be no fault with the CAN as the communication seems to happen successfully.


              The modified project is attached.