5 Replies Latest reply on Sep 17, 2018 2:47 AM by brvi

    CY8C4025 pin jammed on some Cap Sense Pins

    desmond.tan_1900321

            Hi All,

       

            Please help to advise.

       

            I am using CY8C4025 and wants to simulated button jamming

            (e.g. paste a piece of copper foil over certain button) condition and

            we found some of the buttons are unable to recovered from the

            “jam” condition after CapSense_InitializeAllBaseline.

       

            Flow as below:

      1. Paste a copper foil over one button
      2. All buttons are not responding when pressing
      3. Triggered CapSense_InitializeAllBaseline
      4. All buttons are responding except the one with
        copper foil.

       

      Condition d only happen for below mentioned
      ports. The rest are able to respond even with copper foil over it.

                    
      P0[5], P0[6], P2[1], P3[0], P3[1], P4[1], P4[2]

      Q1) We would like to know if there is a difference over those ports compared

      to others.

       

      Q2) If there isn’t a difference in terms of CapSense, what are the possible

      cause in design resulting it?

        • 1. Re: CY8C4025 pin jammed on some Cap Sense Pins
          brvi

          Hi Desmond,

           

          Can you specify the complete part number of the device you're using?

           

          Regards,

          Bragadeesh

          • 2. Re: CY8C4025 pin jammed on some Cap Sense Pins
            desmond.tan_1900321

            Hi Bragadeesh,

             

               The PN is CY8C4025LQI-S412.

            • 3. Re: CY8C4025 pin jammed on some Cap Sense Pins
              brvi

              Hi Desmond,

               

              Are you using Cypress pioneer kit / prototyping kit for testing?

               

              For now I can see that:

              1. 0[5] -> can't be used for Capsense as it is reserved for use by WCO clock.
              2. 0[6] -> If you're using pioneer/ prototyping kit, this pin already has a sensor connected to it. If you're connecting another sensor to this pin, this will effectively increase the Cp of the sensor. If you're not using these kits, then there should not be any problem in using them as capsense pins.
              3. 2[1] -> In pioneer kit, it is connected to capsense sensor. In prototyping kit, it is connected to a LED.
              4. 3[0], 3[1], 4[2] ->  These pins supports capsense. There should not be any problem in using these pins as Capsense. Kindly check the Cp value of the sensors.
              5. 4[1]-> CMOD capacitor connected to this particular pin in both the kits

               

              Regards,

              Bragadeesh

              • 4. Re: CY8C4025 pin jammed on some Cap Sense Pins
                desmond.tan_1900321

                Hi Bragadeesh,

                 

                   Thanks for the reply.

                 

                   Are you using Cypress pioneer kit / prototyping kit for testing?

                   <Answer> : No. I am using my own PCB.

                 

                   Thus, I should be able to configure the above for Capsense usage right.

                 

                   If yes, what are the cause of the pheonmen that I am seeing?

                • 5. Re: CY8C4025 pin jammed on some Cap Sense Pins
                  brvi

                  Hi Desmond,

                   

                  4000S supports capsense on all the pins. Hence there is no difference in capsense in any of these cases. Please reconfirm the following points:

                   

                  1. Please check if there are any other connections made to these pins.

                  2. Where have you connected your CMOD capacitor?

                  3. Are you using the same button to different ports and doing the experiment?

                  4. Try to analyse the pins in Tuner and check if the baselines are getting updated for these pins after the InitialiseAllBaseline command.

                  5. Try implementing the same experiment with the latest version of Capsense component. (v5.10)

                   

                  Regards,

                  Bragadeesh