I've implemented Microchip Application Note AN1298 Capacitive Touch Using Only an ADC ("CVD")
( http://ww1.microchip.com/downloads/en/AppNotes/01298A.pdf ) in a demo for the Curiosity Low Pin Count demo board (PIC16F1619) which has a PCB sensor button, but the code is sufficiently commented with reference to AN1298 that it should be fairly easy to adapt for other microprocessors.
I've implemented Microchip Application Note AN1298 Capacitive Touch Using Only an ADC ("CVD")
( http://ww1.microchip.com/downloads/en/AppNotes/01298A.pdf ) in a demo for the Curiosity Low Pin Count demo board (PIC16F1619) which has a PCB sensor button, but the code is sufficiently commented with reference to AN1298 that it should be fairly easy to adapt for other microprocessors.
See: https://github.com/Anobium/Great-Cow-BASIC-Demonstration-Sources/blob/master/Vendor%20Boards/Microchip-Curiosity_Low_Pin_Count_Demo_Board/cvd_touch_button_16f1619.gcb
Very nice. Good job Sir.