Resistive Touchscreen Overlay

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Shir
 
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Joined: Mon Apr 23, 2018 1:13 pm

Resistive Touchscreen Overlay

Post by Shir »

Hi,

I am interested in your product:
Resistive Touchscreen Overlay - 7" diag. 165mm x 105mm - 4 Wire

I want to put it on the floor of a Skinner Box (https://en.wikipedia.org/wiki/Operant_c ... ng_chamber) in order to detect when the mouse arrive to certain areas of the box.

My question is:
Is there a limit to the number of points the pad can detect?
I ask this since the mouse will touch the pad with 4 legs and a tail. Will the pad be able to detect all 4 legs and the tail?

Thanks!
Shir

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adafruit_support_mike
 
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Joined: Thu Feb 11, 2010 2:51 pm

Re: Resistive Touchscreen Overlay

Post by adafruit_support_mike »

You can only get one X/Y reading from the touchscreen, no matter how many points of contact there are. The value you get will be some kind of average for all the points that do connect.

The touchscreen is basically a wide soft potentiometer. The upper and lower layers have resistance, and the point where you touch forms a voltage divider. If you touch multiple points, you get multiple voltage dividers in parallel.

The amount of connection you get also depends on the strength of the force pressing the layers together, so varying pressure at any point of compression will make the output change.

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