3 Replies Latest reply on Jul 11, 2018 11:18 PM by nmit

    capsense key false detection

    abhay.tambe

      hey I am using PSoC4 device for capsense keyboard. till date i manufacture more than 1000 boards, presently i am facing problem that without key press i am getting as key press input . this is not in all board but in some boards anyboady can help me?

        • 1. Re: capsense key false detection
          ring

          You need to select the false touch board, and  tuner it.

          Does these boards have a high noise?

          Does these boards have a poor consistency?

          Can you tell me how you set the finger threshold, noise threshold and hysteresis?

          At the same time, you need to clarify what device you do, and what the working environment?

          • 2. Re: capsense key false detection
            abhay.tambe

            thanks for the reply

             

            1. power supply no noise as it is connected to USB port

            2. I am using auto tune mode so i have not tune it manually

            3. device is CY8C4245AXI-483

            4. this problem i am facing in 1 or 2 board out of 100 boards.

            5. working environment is normal. even on lab table with temp 25 degree

            • 3. Re: capsense key false detection
              nmit

              Hi Abhay,

              Sometimes due to manufacturing tolerance, board to board variation can happen in terms of thickness and material use.

              I recommend to check the Cp of the CapSense on those boards. The Cp would certainly be different from the passed boards and that is the reason it would have failed.

              2nd there could be Pin shorts to GND or Open which can lead to this issue.

               

              Regards

              Nishant