Light Switch with ZWave and Bare Conductive Paint


My idea is to create a light switch that is drawn on the wall, and when touched, it will turn on/off a switch controlled via ZWave protocol.

The idea comes from the Bare Conductive Touch Board

Unfortunately, they do not have WiFi integrated, and the shields are pretty expensive.

So, the technical question is(
For simplicity, Bare Conductive Paint acts exactly as a wire, so we will call it a wire.): How can I make the Spark IO input know when I touch the wire with my finger? Do I need an extra cip or something? How can I do it as simple as possible?

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ST (who makes the STM32 micro-controller) has some documentation and a library for using the STM32 as a capacitive touch controller:

I haven’t tried to do this myself but it is possible to do it with just the MCU. That said, I believe it is much easier to purchase a chip that will handle the capacitive touch sensing itself and has an I2C or SPI interface.

I would not try and do capacitive touch directly via the web GUI, at least not for a while yet, once all the loose ends get shaken out.

Until then, try using something like these instead:

Now, neither may work very well with just some random conductor on a wall, but there’s only one way to find out !

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