Enable/Disable CapSense Shield Programmatically

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TyFo_1975986
Level 1
Level 1

I would like to use my chips shield pin to determine if there is a 0 Ohm resistor connecting two hatchedplanes on my board on startup. If the resistor is sensed I would then like to Enable the CapSense shield. If the resistor is not sensed I would then like to Disable the CapSense shield. Seeing that the hatched planes are parallel hatched planes I would think I could measure the capacitance and it would change with/without the presence of the resistor connecting them. I have attached an image of the board as reference. The red hatched plane is connected to the shield pin and when the the resistor (R5) is present the blue hatched plane is also connected to shield. When R5 is not present, R6 is, which then makes the blue hatched plane a ground plane. 

   

So, my question is: How/can you Enable/Disable CapSense Shield programmatically? and would it be possible to use the shield pin to sense the presence of the resistor?

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Yuva
Moderator
Moderator
Moderator
250 replies posted 250 sign-ins 100 solutions authored

Hi,

   

 

   

There is no direct API to enable and disable shield electrode. You might need to check the register TRM in the  following link

   

http://www.cypress.com/file/136301/download

   

Shield signal will be the square wave similar to the sensor signal so sensing the resistance using this shield may not be possible. 

   

 

   

Thanks,

   

Yuva.

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1 Reply
Yuva
Moderator
Moderator
Moderator
250 replies posted 250 sign-ins 100 solutions authored

Hi,

   

 

   

There is no direct API to enable and disable shield electrode. You might need to check the register TRM in the  following link

   

http://www.cypress.com/file/136301/download

   

Shield signal will be the square wave similar to the sensor signal so sensing the resistance using this shield may not be possible. 

   

 

   

Thanks,

   

Yuva.

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