LCD/touch screen to measure pressure

[bonner]

can an lcd monitor or a touch screen monitor measure pressure? also, is it possible for them to measure the x-y coordinates of more than one touch at a time (the four paws of a rat for example)? any information on the subject would be much apreciated. thanks in advance.

 

[MovieMan80]

can an lcd monitor or a touch screen monitor measure pressure?

no

also, is it possible for them to measure the x-y coordinates of more than one touch at a time (the four paws of a rat for example)? any information on the subject would be much apreciated. thanks in advance.

probably not (but depends entirely on the screen and you'd still probably have to write a custom driver)

There are two types of touch screens, the most common one that I've seen uses two thin sheets of conductive material with a grid of tiny balls in between them to keep them separated. Pushing on the screen causes the two screens to touch and make a connection. Since it's either they touch or don't touch there is no middle ground to interpret pressure. The other kind of touchscreens I can't remember functionally how it works but I'm sure wikipedia or howstuffworks will have a writeup on it.

Since your fingers are a lot bigger than a pixel, the screen takes the midpoint of all the x and y coordinates. (Just for fun touch a touch screen on the left and right sides at the same time, the cursor will end up in the middle of the screen away from all your fingers)
I don't know if this averaging takes place on the screen itself and it sends the midpoint back to the computer, or if it sends all the data back to the comptuer and the screens mouse driver handles the interpretation.