3 Replies Latest reply on Dec 5, 2019 10:25 PM by AH_96

    Guard Sensor implementation with two CY8CMBR3116 supporting 20 buttons


      On the board I designed, two  MBR3116 are fitted to support 18 buttons. Each group of 9 buttons ( 3 row x 3 column)  is surrounded by its corresponding shield. Keypad is 3 row x 6 x column


      The distance between buttons is 22 mm and the buttons diameter is 12 mm.  There is a GND trace separating two shields to prevent cross-talk.


      I would like to include Guard sensor. If I select rectangle loop for Guard,  I cannot run two Guard traces plus shield and GND tracks between grouped sensors as 22 mm spacing is not enough.


      I have two questions;



      1) Does Guard sensor have to be a loop? Can I use 'C' shape around left group of buttons and mirrored 'C' around the right group?  

      2) When the Guard sensor is scanned, is the shield active or disabled? In other words, Guard is dealt with same as any other button?