I have implemented capacitive touch sensing using a PIC in a handheld terminal project. I needed the ability to sense up to 32 touch pads (and control a 128x64 pixel graphic LCD) and went with a different approach that did not require a PIC with a CSM module or comparators. I used an external oscillator (a CMOS version of the 555 operating at 2MHz) - this approach allows it to be implemented with any PIC (or other processor such as Atmel, MSP, etc. - I used a 44-pin PIC18F44K20 which controls everything). Works real well. Front and rear pics of the prototype below.