CapSense Proximity Sensor

Tip / Sign in to post questions, reply, level up, and achieve exciting badges. Know more

cross mob
Anonymous
Not applicable

I'm currently looking to use CapSense in a proximity sensing application. The hoped for range is 30 cm with a 100 Hz sample rate.

   

Looking at old Research, if you use a Capaciflector it may be possible to extend the range of the sensor. Basically behind the sensor you place another sensor (with a further ground plane behind that one) and at the same time send the same excitation signal to both sensors.

   

(It seems that it may be possible using the PSOC Mutual Capacitance mode (CSX) to send the same signals to both sensors synchronously) <- Not true.

   

Driving the second sensor using the  Shield Signal seems like one way to emulate this technology (Synchronous with sensor signal).

   

On another level, we may build our own sensor, just to confirm how effective this is. Does a proximity sensor shield exist which uses the above multi-layer sensor idea, exist?

0 Likes
1 Reply
Anonymous
Not applicable

Hello,

   

Cypress has the below proximity sensing shield and it doesnot use the Capaciflector which you are describing.

   

http://www.cypress.com/documentation/development-kitsboards/cy8ckit-024-capsense-proximity-shield

   

 

   

But it is possible to achieve large proximity distance with our PSOC4 devices with large enough sensor loop.

   

As a rule of thumb the recommendation is to have a sensor loop of diameter/diagonal  equal to the required proximity distance.

   

This sensor loop can also be reduced with the help of the ALP filter.The details about the proximity sensor design can be found in the below document (AN92239 -Proximity sensing with capsense--page 9 section 6.2)

   

http://www.cypress.com/file/46741/download

   

 

   

Thanks,

   

Ranjith

0 Likes