[Duo2400] off the wall project

[Jani Tiainen]

> That got me thinking about somehow building one out of a duo.  What I
> thought I might do is somehow build a duo with an etherdock, connect it
> to an airport base station and wirelessly connect to it with my
> wallstreet, which has a wireless card.  Any ideas on how to build a big
> scoreboard and then output to this from a duo?

Well this highly depends on how big characters (and how far they must be
visible) you want to build.

LEDs are good (durable, small), but expensive if you want to build big
characters / numbers. Of course you can use LED modules which are a bit
cheaper than invidiual LEDs but still.. EG rectangular 112.5 x 48 x 6.7mm
segment costs something like $20 - $40 (mostly depending on color of LEDs)

But that's not a problem. It's "just money". For a 7 segment display you
need of course 7 big LED modules for each number.

one LED module draws power 60mA (red, yellow) or 120mA (green, blue, white)
@10VDC.

Now for each segment you need proper component that can drive segment, with
proportionally low power and voltage... For a brains of such a scoreboard
could any uC do a good. well you could control that scoreboard with DUO, or
of course with that uC (but uC could be used for a just a LED driver).

Still cost is pretty high. For a 3 x 7 segment numbers and two sides (home,
visitors) you need 42 separate modules, which makes $840 to $1680, pretty
much eh...

Cheaper solution would be using eg. E10 socketed neon lamps (diameter 10mm)
. for a $50 you get 100 pieces of them... (w/o sockets)
Sockets (metallic can't be used for 110/220 volts, so have to use bakelite
ones) are $1 for each. Of course you need something to drive these lamps
(like fast relays, transistors...) amd then you need uC to keep numbers in
showing them. Then again, you could use uC to handle displaying, or DUO for
controlling those segments. (well, you could use also just plain binary/BCD
to 7-seg display converter) and drive these converters from DUO...

But using DUO as a display isn't good. it has poor visibility and very
limited field of viewing. Using "normal" 7 seg displays well, they're
prettty tiny...

Another thing could be asking how much costs using those neon lamps used in
signs. (Used in bars, clubs and such those which blinks and beeps =) They
might not be that expensive after all..

Of course sometimes you can get lucky and get those old big bulb-based signs
from airports and such when they're renewing and modernizing their
announcement systems.

Jani Tiainen

"I don't suffer from insanity, I enjoy every minute of it!"