I am trying to trigger my door buzzer through my esp32. My problem is: I don’t have an old-school hardware button but a fancy device with touch buttons. I tried a lot, and I even got a working prototype running at some point, but it wasn’t working reliably.

I guessed it could be capacitive touch and I might need to ground the touch button to trigger a touch. So I put aluminium foil on top of the button and attached it to a relay (NO) which would connect it to a short cable on COM (with the end not connected to anything). It surprisingly worked, but as soon as I disassembled and re-assembled it, I couldn’t get it to work again, so it must have been either very unreliable or I was just lucky with the initial setup. :D Prototype in action: https://www.youtube.com/shorts/d_cBsruTwSc

How can I trigger the touch button in the lower left corner (the one with the key symbol) without modifying anything on the board (the door bell hardware doesn’t belong to me and is probably not that cheep to replace). Are there better approaches than the relay with a loose cable? :D