Follow

PCB noob here: is there a good resource on how to make capacitive touch buttons on PCBs (dos and don'ts)?

@bleeptrack@chaos.social don't know much myself, look for application notes and general specs in the datasheet for your capacitive sense chip.

Many vendors put out detailed docs for pretty much anything more complex, like power switching regulators and such.

Here's an example by SL:
https://www.silabs.com/documents/public/application-notes/AN0040.pdf

@bleeptrack this might be obvious, but make sure to use lead-free surface finish! I once tried this Arduino code playground.arduino.cc/Code/Cap and it worked well.

capacitive touch 

@sebastian true capacitive sensing does not use exposed metal contacts

@bleeptrack it depends on the capacitive touch controller you use; look into its datasheet for recommendation

from an UX perspective, some kind of feedback is absolutely necessary

I personally find capacitive touch most of the time rather annoying and inferior to tactile switches, but there surely are applications where it is the way to go

@bleeptrack My own experiments in that field ended up with "it's all too finicky". It all depends on cable lengths, other capacitances/inductors in the vicinity, whether your circuit is grounded, etc...
So, as an unasked-for alternative, I can only give you the hint to check out touch button modules that have that problem solved. My go-to module is the Heltec HTTM Touch Module (LED backlight, configurable via solder bridge as monostable button or bistable switch).

Sign in to participate in the conversation
chaos.social

chaos.social – a Fediverse instance for & by the Chaos community