First, get a detailed understanding of how your circuit works. What are the voltages and their ranges going into the DRV5033, for example. Also understand what kind of signal goes from the DRV back to the control chip. Next, look at all the capacitive sensors you can find, and see which ones match the circuit you already have, minus the DRV, of course. Then buy a couple of different cap sensors so you can experiment a bit. Buy more than one of each in case you fry one. Remove the DRV from the existing circuit board, no wire in the cap sensor. Even better, solder in some small pins so you can change the cap sensor easily. Work very carefully, and methodically. Then test on the bench, and finally in an installation.
I have ordered and received some Atmel AT42QT1012's. They DO work but I think I'm going to have to change some stuff around. My LEDs will not stay on for more than 5 seconds when activated with the Atmel. I believe my code has something to do with this and will have to take a further look into that. Cypress puts out a lot of capsense products so I have ordered an evaluation board to check it out. It would be nice if Cypress works because I can replace my MCU with their IC and still have all the same functions I currently have. Will keep you posted on what I come up with in the next couple weeks.
