Simon-Pedersen
Newbie level 2
This is problem
I am currently in a project, where the end product needs to implement 3 (binary)capacitive touch buttons in the final product. The buttons have to be attached to the bottom of a 15.3 mm thick glass panel which is 8 cm. in diameter due to safety reasons.
This is what I have done so far
This is what I have found so far
I found two IC's which might work:
I would like to find a IC which could live up to specs with a minimum of pins, but is not overkill i.e. does not have the ability to implement 24 buttons. My experience with touch capacitive sensors is at a minimum and any advise from someone more experienced would be much appreciated.
I am currently in a project, where the end product needs to implement 3 (binary)capacitive touch buttons in the final product. The buttons have to be attached to the bottom of a 15.3 mm thick glass panel which is 8 cm. in diameter due to safety reasons.
This is what I have done so far
- I brushed of on the theory of capacitive touch sensors.
- I tried implementing the touch sensing using the CTMU unit of a pic24fj128Ga204 mcu. I got the CTMU unit up and running but was quickly able to conclude that the sensitivity of the unit would require a very big sensor(touch surface) to comply with specs which was not a viable option.
- I Have searched various vendors(Farnell, Mouser, Digikey and RS components) for an IC which could live up to specs.
- I have read microchips QTAN0079 Capacitive touch sensor design guide.
This is what I have found so far
I found two IC's which might work:
- CY8CMBR3002 which according to their datasheet says can sense touch through glass panels of 15 mm of thickness which is on the verge of specs, but might be allright.
- Atmel AT42QT1245 which according to their datasheet can sense touch through glass panels of 50 mm thickness but comes in a 32 pin packet with the capability of implementing 24 touch buttons, which is overkill given I only need to implement 3.
I would like to find a IC which could live up to specs with a minimum of pins, but is not overkill i.e. does not have the ability to implement 24 buttons. My experience with touch capacitive sensors is at a minimum and any advise from someone more experienced would be much appreciated.
