I am working on a bluetooth game controller project and I am thinking of using the same analog stick that you are using (N50p105 + AS5013). Do you know to what the center pads of the N50P105 are supposed to connect, if anything? I would include an image, but I can't figure out how attach my diagram to this message. If you look at the recommended PCB layout for the N50P105 on the datasheet, it is the center circle pad and the adjacent two rectangle pads. I have tried contacting AMS support, but haven't heard back from them yet.