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Topic: Arduino as Capacitive Sensor (Read 33860 times) previous topic - next topic

Chris Dragotta

I would like to try this, but a bit about my application.

I'm trying to create a midi bend up and midi bend down plate on either side of the right thumb for an "Electronic Wind Instrument" application.

What I need is for each of those sensors to return a value of 0 - 128) smoothly, as a function of how much skin is touching a piece of copper about a 1/2" square.

No skin contact needs to equal 0, and then as the thumb is rolled slowly onto the capacitance sensor, I need a smooth rise up to 128.

Is this even possible?  Because I will not investigate this further if it is not even possible.

CD

Thanks.


mowcius

It is relatively easy to measure the distance of someone's hand away from the sensor and map that value from 0-128 but it is not very easy to do it for the amount of skin touching the 'pad'. The capacitance measured would be very small differences so it would need to be very accurate. This would then change from person to person and humidity etc.

I think you may be better off with a force sensor...

Mowcius

Endee

Hi,
I was to ask please how do I get the output to an LED or how do I observe the output

mowcius

This looks remarkably like spam. Maybe we'd better watch it.

If not, then I don't understand the question and this isn't the right place to post it.

Endee

Hi,
I have done this experiment on capacitive sensing using the available codes on this page. Can anyone tell me how to convert the signals to the motion of a cursor on my computer so that when I move my hand around the cooking foil (sensors) the cursor will also move. Same as  a mouse motion :)

Bobnova

I just want to say thank you!
I've been playing with this, it's quite interesting taking measurements of various things and testing different sized sensors.
Eventually it'll find it's way into a paranoid robot that runs away when you try to pick it up :D

Endee

Bobnova,
please can you give me an idea i don't have the slightest idea on how to make the magic work ;)

mowcius

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please can you give me an idea i don't have the slightest idea on how to make the magic work


I'm sure you told me you had it working with the one sensor?

Then just add another, get it to send serial and then use some software on your computer to convert it into very innacurate mouse movements.

Mowcius

Endee

Ok thanks mowcius. where do i connect the second sensor to

Endee

sorry, i mean what pin on the ardiuno do i connect the second sensor

mowcius

Which ever pin you like.

You then just have to add it in the code.

julcsi20

Hello all,

I am currently working with the CapSense library to create capacitive sensors with Arduino. I managed to make some sensors (made of copper wire) work but I will need 16 sensors (there are no enough digital pins for that). Does anyone have experience with using a 4051 or 4067 analog multiplexer with capacitive sensing?

Thanks in advance.

PS. The sensors do not have to output super-precise values.

mowcius

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there are no enough digital pins for that

There are. You can use the analog input pins as digital pins too.
Numbered 14-19

julcsi20

First of all, thanks for the fast answer.

It might be a solution, I'll try it with the analog pins.
There is only one drawback left: I still have to run a led driver that takes up 5 digital pins (13, 11, 20, 9, 4). Anyhow, I cannot avoid using a multiplexer, I hope someone has experience with that.

mowcius

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I hope someone has experience with that.

They're not too tricky but I would suggest using the LED driver through the multiplexer as the capsense library may be a pain to use through one.

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