1 Reply Latest reply on Oct 21, 2018 6:27 PM by xzng

    PSOC 4 waterproof cap touch design

    pylin_1601451

      CapSense_CSD component datasheet state below:

      Not recommended to use the shield electrode with SmartSense tuning mode.

       

      If we don't use SmartSense tuning mode, can we use Manual with Run-Time Tuning when the shield electrode is enabled.

       

      What should we take care of when we use Manual with Run-Time Tuning or Manual mode in a output door environment with shield electrode enabled. Do we need to do manual tuning in firmware.

        • 1. Re: PSOC 4 waterproof cap touch design
          xzng

          I think this limitation is only possible when the SHIELD hatch itself has large parasitic capacitance(CP), for example big size washing machine touch panel with water proof feature.  The characteristic of this kind of boards is big size board plus large shield hatch area(large shield cp), the sense clock divider calculated by SmartSense may not satisfy the shield hatch be fully charged and discharged during sensor scanning (waveform on sensor and shield are not synchronized). This may cause poor SNR or sensors.

           

          For small size touch board, use shield and SmartSense together is not a problem. For Manual with Run-Time Tuning or Manual mode, you can set the sense clock divider by yourself, so use shield and SmartSense together is also not a problem.