[sdiy] 8 wire touchscreen

[Paul Maddox (QinetiQ)]

Craig,

> Here's a tech docs page at 3M:
> http://www.3m.com/3MTouchSystems/downloads/tecdoc.jhtml
>
> Near the bottom of the page is this PDF:
> http://www.3m.com/3MTouchSystems/downloads/PDFs/18172sc3rev4WEB.pdf

excellent, thanks..

> It's docs on a touchscreen evaluation board.  There's a pinout and pin
> description of 8-wire touchscreens in this documents.  It looks like
there's
> 4 lines to drive voltages along the edges and 4 sense lines, one on each
> edge.

Ive been doing some digging and this seems to be the way, though some
switching of the supplies can be done to get auto calibration.

> Touchscreens are fun; I recently built an analog controller out of a
surplus
> 5-wire.  How large is the one you salvaged?  The 3M docs say the 8-wires
> tend to be the larger ones.

its big :-)
12" by about 8"
Fits over my 8" by 6" EL display rather nicly, now just got to figure out
how to mount the two onto a panel...

Paul