Perhaps this might give you some ideas:
http://www.sparkfun.com/commerce/present.php?p=GPSClock-1
On Wed, 4 Oct 2006, Jules Richardson wrote:
I got to wondering how to make a large numeric display
(a few inches high) for
a potential project. I've only seen 7-segment displays up to about an inch in
height, plus I quite fancy something with more rounded numerals anyway (all of
this came about from thinking about Nixies :)
Building something from individual LEDs looks to be cost-prohibitive, not to
mention power-hungry; I think I figured on over about 125 LEDs per digit.
I came up with something based on 23 segments which I think will look nice.
Basically a 14-segment grid like the following:
_ _
| |
|_ _|
| |
|_ _|
... then with each square part containing a circle split into four segments.
Finally a central segment runs top to bottom to give a '1' digit centered
horizontally. (I'm not going to try and draw arcs in ASCII ;)
I need to do some tests to see how well light from an LED will travel through
perspex (plexiglass, or whatever the preferred term is) if I mount the LED at
one end of a strip, box off three sides with metal foil, and (maybe) polish
the exposed side. In theory I can easily shape that to give the arcs that I
need, too.
Of course all of this is just a precursor to see if anyone else has built big
displays like this as part of a project, and what they found worked well (or
otherwise)
It may be that I can get away with having the curved sections live 'inside'
the boxes (i.e. it won't be noticeable from a distance anyway), so that there
are no points of overlap; time will tell there.
Heck of a lot easier driving 23 LEDs per display rather than five times that
amount, anyway! If it's technically possible, the issue will be how long it
actually takes to make each digit and get it right, though. Ideas are welcome...
cheers
Jules
--
A. Because it destroys the natural flow of conversation.
Q. What's wrong with top posting ?