Re: DIY Touch Screen

[Steve Morgan <steve@xxxxxxx>]

A possible alternative to my own suggestion!....

http://www.magictouch.co.uk

offer a clip-on touch screen kit for 13-15" monitors for =A3199 + VAT
=
or a
17" version for =A3249 + VAT

Still like to see if we could do something cheaper though.

Steve

>  -----Original Message-----
> From: 	Steve Morgan =20
> Sent:	Saturday, July 24, 1999 10:55 PM
> To:	UKHA_D (E-mail)
> Subject:	DIY Touch Screen
>=20
> Folks,
>=20
> Continuing the monitor theme, has anyone got any thoughts on
> constructing a touch screen to retrofit to a standard (CRT or LCD)
> monitor.
>=20
> I'm sure I've seen before units that use an array of infra-red
> emitter/receiver pairs but I've got no idea where.
>=20
> So the question is, what's the scope for coming up with our own?
>=20
> The idea is this... a bezel that fits on the front of an existing
> monitor with a row of IR LED's along X & Y axes with corresponding
IR
> photodiodes opposite (say, 16x16 giving 256 crosspoints). If you can
> minimise the spread from the emitters, I would have thought that a
> fairly simple microcontroller-based module could handle the scanning.
> The thing I'm not sure about is that issue of minimising the spread.
> An IR LED has a spread of about 60 degrees, if I remember rightly.
> Thus I would expect to several photodiodes to detect the signal from
> each of the emitters. How about simply recessing the emitters? If a
> different modulation where used for each emitter/receiver pair, would
> that help? What about reflections?
>=20
> Any ideas, suggestions, other issues?
>=20
> I quite like the idea of bits of 2x2" timber glued to the front
of =
all
> my monitors!!
>=20
> Steve
>=20
>=20
>=20

------------------------------------------------------------------------
Want the power to purchase wisely? Productopia has the answers. =

http://clickhere.egroups.com/click/553


eGroups.com home: http://www.egroups.com/group/ukha_d
http://www.egroups.com - Simplifying
group communications