Inducing capacitive buttons

I’m posting this as a curiosity for anybody who might have experimented with this in the past or is interested in experimenting with it.

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A coil is probably not the way to go here but I’d like to know more about the technology being used. Most appliances use membrane touchpads that are actually a bunch of switches.

However, I’ve seen a few washers that actually use capacitive buttons and it might be possible to use some foil stickers with wires connected to them to control those. I’m talking about connecting a those stickers to a ground of some sort.

In any case, this reminded me of this particular technology that I wanted to use for a product that never materialized:

Yeah these are definitely capacitive. There is no give at all when pressed, and I can barely cover my finger over them with hardly any pressure aside from gentle contact and they activate.

What about instead of a coil, a pair of metal discs separated by a thin insulator and then you simply apply a field potential to them?

Found this guy’s Switchbot mod, might be useful. I guess it’s still technically mechanically pressed. It might be the simplest solution, I’ve had good experiences with Switchbots.


Would have to put some sort of capacitive material on the end of the bot finger id imagine… metallic tape is interesting

A piece of metal that’s connected to another large piece of metal is what you need.

i wondering if there is a way to emulate this electronically without moving parts… my hunch is that a capacitive plate with a slight field potential put across them with the proper polarity would do it… might test with a AA battery and some foil later.

I’d go for a small piece of metal on the button and a switch of some sort to connect it to a large piece of metal nearby. It should work even better if that large metal part is near the metalwork of the washing machine.

The touchpad should provide all of the electric fields required. I don’t understand why you want to add a AA battery?
I should probably post a detailed explanation of how those capacitive buttons work when I’m somewhat less busy and back in front of my computer. And I’m sorry if things are not clear.


I tried something similar before, they decided to switch the intercom units in the building.
Got something to work with arduino, small capacitor and a transistor. It did trigger the capacitive touch.
But sometimes it would glitch and keep triggering it after i touched the button myself.
Maybe with an optocoupler to have less interference? I dunno :smiley:

gave up on using this approach and used the CSC-bus interface :slight_smile:



How did you wire that? I’m not quite understanding what you did but it does sound awesome.

what about using WLED?

If you can dump WLED to an ESP8266, and wire it up like an LED strip with each button being an “led” you can create different scenes in wled for each of the buttons. Then you would be able to use any smarthome automation to call WLED to play that scene.

The LED’s could just be a diode/resistor combo connected to a small coil. and your entire setup could be controlled by 1 esp8266 and a usb cable.

I dont have anything with capacitive buttons otherwise id quickly mock something up. and i already have a few other failed projects that have came in through JLCPCB otherwise i could easily make a quick flex pcb that overlays the panel.

Cool thought project though. if i had something that used it id rip up one of my addressable led strips to put the theory to practice.


I think i did something like this, :smiley:


I’m getting a 404 when I try to play the video. File no longer found.

Yeah, It could be a Backblaze issue.
Amal is looking into it

Oddly it just started working again.

I wonder if it’s time of day. Not working for me in the middle of the day. Responds with 404, and the text says “Key not found”. Maybe upload it again? I’d love to see the video so that I know what everyone is talking about on this thread :slight_smile: , otherwise maybe YouTube?