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[on:]

Hello!
In my bedroom, I have a light dimmer / switch (100_0016.JPG). What kind of dimmer is it? Is it a...
a) Capacitive Sensor
b) Pressure Sensor
c) Something else (specify)

How do capacitive sensors work?

Thanks!

[Reply #1 on:]

What kind of dimmer is it?

No idea from that blurry photo.

 

a) Capacitive Sensor
b) Pressure Sensor
c) Something else (specify)

How do you interact with it.
If you can control it with out actually touching it then it is capacitive. If you see some deformation before it changes then it is pressure.

How do capacitive sensors work

By sensing capacitance between the plate and ground as your body affects it.

[Reply #2 on:]

No idea from that blurry photo.

How much more detail is there to see? If you don't maximize the photo, it will be easier to see (my camera takes 5.0 Mega pixels).

How do you interact with it.

You touch it with your finger. The pad seems to be made of metal, but I have a similar dimmer with a plastic coating.

By sensing capacitance between the plate and ground as your body affects it.

Would the "ground" be "the Earth" in this case?

In Arduino, capacitive sensing only works when you connect it to the Earth somehow (e.g. desktop, USB adapter). Why can't Arduino use the battery's negative terminal as a ground?

[Reply #3 on:]

If you don't maximize the photo, it will be easier to see

There is no choice with this forum.

Would the "ground" be "the Earth" in this case?

Yes

In Arduino, capacitive sensing only works when you connect it to the Earth somehow

No you can get capacitance between any two connections.
The arduino capacitance sensor method is not very good, it is only a sort of demo.
To do it properly you need a controlled layout and an oscillator that changes with capacitance then you measure the frequency.

The pad seems to be made of metal

So that could be an inductive injection. Or it could be capacitive.

I have a similar dimmer with a plastic coating.

So that would be capacitive.

It is extremely hard, if not impossible, to tell what a circuit is doing by just looking at the outside case.