Massive LED Display
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Posts: 46,084
Hi stampers,
My name is Doug McClean and I am looking for a bit of advice on a
project proposal. Its my job to decide if this project is feasible
and to draw up a budget for it, so I thought I'd try to draw on this
group's vast experience [noparse]:)[/noparse].
The project:
Construct a 4096 independently-addressable element LED display
spanning an area of about 12 square feet. People must be able to get
the general graphical impression of the display from a distance of
10-15+ feet outdoors (in fair weather, but just for reference to the
ambient lighting). 120 VAC is available to power the project. As
much as $2000 could be available for this aspect of the project, but
minimizing costs is a top priority. The project is for a high
profile educational institution, we have plenty of EE students to
draw on and may be able to finagle some part donations. It would be
desirable if the display could be wiped clean and redrawn
differently in 5-10 seconds or less through instructions from a
laptop.
My questions:
Does anyone have any suggestions for how best to address these LEDs?
I found a chip from Maxim (the 6953) that can address them in chunks
of 128 over an I2C bus, I would still need 32 of them, but that
might not be the worst thing ever because it would keep the wiring
neat.
Do you think this is doable for $2000?
What sort of LEDs would you recommend using?
Thanks a lot, as always,
Doug McClean
jxm156@p...
216/754-1995
My name is Doug McClean and I am looking for a bit of advice on a
project proposal. Its my job to decide if this project is feasible
and to draw up a budget for it, so I thought I'd try to draw on this
group's vast experience [noparse]:)[/noparse].
The project:
Construct a 4096 independently-addressable element LED display
spanning an area of about 12 square feet. People must be able to get
the general graphical impression of the display from a distance of
10-15+ feet outdoors (in fair weather, but just for reference to the
ambient lighting). 120 VAC is available to power the project. As
much as $2000 could be available for this aspect of the project, but
minimizing costs is a top priority. The project is for a high
profile educational institution, we have plenty of EE students to
draw on and may be able to finagle some part donations. It would be
desirable if the display could be wiped clean and redrawn
differently in 5-10 seconds or less through instructions from a
laptop.
My questions:
Does anyone have any suggestions for how best to address these LEDs?
I found a chip from Maxim (the 6953) that can address them in chunks
of 128 over an I2C bus, I would still need 32 of them, but that
might not be the worst thing ever because it would keep the wiring
neat.
Do you think this is doable for $2000?
What sort of LEDs would you recommend using?
Thanks a lot, as always,
Doug McClean
jxm156@p...
216/754-1995
Comments
Most likely.
If you don't need balanced video color, the first thing will be to find a
good source for the LED's. I believe you'll need something in the 3,000 MCD
range (which will work better if you don't need wide angle viewing) Getting
these at the price you need will be a real challenge - better look for a
donation here first. As for the exact brightness required for your
application. there was an excellent article in Electronic Design Mag about
1/2 year ago on this, which also included a nice list of sources and contact
info.
The last time I dealt with a similar project (some years ago) the next
largest cost contributing factor was getting good power to all the LED
loads. The best bang-for-buck method turned out to be PC power supplies.
These are often available as new (or nearly new) surplus for about $5 US
each for a couple of Amps or more. The balance of the $ (If you don't have
to pay for design hours) will be in wiring materials. I believe your target
cost is attainable only if you secure some significant donations.
Chris
>
Original Message
> From: idiggles [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=ThrMFqXOgwFeS1QwrILyXwDa8Q9_TVy1GYlH1cfR4EebBzXs3goXK0FS3ltmPPzGbsR672LhjQ]IDiggles@a...[/url
> Sent: Sunday, March 24, 2002 5:38 PM
> To: basicstamps@yahoogroups.com
> Subject: [noparse][[/noparse]basicstamps] Massive LED Display
>
>
> Hi stampers,
>
> My name is Doug McClean and I am looking for a bit of advice on a
> project proposal. Its my job to decide if this project is feasible
> and to draw up a budget for it, so I thought I'd try to draw on this
> group's vast experience [noparse]:)[/noparse].
>
> The project:
> Construct a 4096 independently-addressable element LED display
> spanning an area of about 12 square feet. People must be able to get
> the general graphical impression of the display from a distance of
> 10-15+ feet outdoors (in fair weather, but just for reference to the
> ambient lighting). 120 VAC is available to power the project. As
> much as $2000 could be available for this aspect of the project, but
> minimizing costs is a top priority. The project is for a high
> profile educational institution, we have plenty of EE students to
> draw on and may be able to finagle some part donations. It would be
> desirable if the display could be wiped clean and redrawn
> differently in 5-10 seconds or less through instructions from a
> laptop.
>
> My questions:
> Does anyone have any suggestions for how best to address these LEDs?
> I found a chip from Maxim (the 6953) that can address them in chunks
> of 128 over an I2C bus, I would still need 32 of them, but that
> might not be the worst thing ever because it would keep the wiring
> neat.
>
> Do you think this is doable for $2000?
>
> What sort of LEDs would you recommend using?
>
> Thanks a lot, as always,
> Doug McClean
> jxm156@p...
> 216/754-1995
>
>
> To UNSUBSCRIBE, just send mail to:
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> Subject and Body of the message will be ignored.
>
>
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http://docs.yahoo.com/info/terms/
> If you don't need balanced video color, the first thing will be to
find a
> good source for the LED's. I believe you'll need something in the
3,000 MCD
> range (which will work better if you don't need wide angle
viewing) Getting
> these at the price you need will be a real challenge - better look
for a
> donation here first. As for the exact brightness required for your
> application. there was an excellent article in Electronic Design
Mag about
> 1/2 year ago on this, which also included a nice list of sources
and contact
> info.
Thanks for the good info Chris. I'm a little worried about the wide-
angle comment. The display isn't flat, its actually going to end up
on the outside of a large sphere. Do you still think it can work?
> The last time I dealt with a similar project (some years ago) the
next
> largest cost contributing factor was getting good power to all the
LED
> loads. The best bang-for-buck method turned out to be PC power
supplies.
> These are often available as new (or nearly new) surplus for about
$5 US
> each for a couple of Amps or more. The balance of the $ (If you
don't have
> to pay for design hours) will be in wiring materials. I believe
your target
> cost is attainable only if you secure some significant donations.
>
> Chris
Power supplies always seem to be a major price problem. I'll be sure
to shop around on that one, thanks.
-Doug
>
> >
Original Message
> > From: idiggles [noparse][[/noparse]mailto:IDiggles@a...]
> > Sent: Sunday, March 24, 2002 5:38 PM
> > To: basicstamps@y...
> > Subject: [noparse][[/noparse]basicstamps] Massive LED Display
> >
> >
> > Hi stampers,
> >
> > My name is Doug McClean and I am looking for a bit of advice on a
> > project proposal. Its my job to decide if this project is
feasible
> > and to draw up a budget for it, so I thought I'd try to draw on
this
> > group's vast experience [noparse]:)[/noparse].
> >
> > The project:
> > Construct a 4096 independently-addressable element LED display
> > spanning an area of about 12 square feet. People must be able to
get
> > the general graphical impression of the display from a distance
of
> > 10-15+ feet outdoors (in fair weather, but just for reference to
the
> > ambient lighting). 120 VAC is available to power the project. As
> > much as $2000 could be available for this aspect of the project,
but
> > minimizing costs is a top priority. The project is for a high
> > profile educational institution, we have plenty of EE students to
> > draw on and may be able to finagle some part donations. It would
be
> > desirable if the display could be wiped clean and redrawn
> > differently in 5-10 seconds or less through instructions from a
> > laptop.
> >
> > My questions:
> > Does anyone have any suggestions for how best to address these
LEDs?
> > I found a chip from Maxim (the 6953) that can address them in
chunks
> > of 128 over an I2C bus, I would still need 32 of them, but that
> > might not be the worst thing ever because it would keep the
wiring
> > neat.
> >
> > Do you think this is doable for $2000?
> >
> > What sort of LEDs would you recommend using?
> >
> > Thanks a lot, as always,
> > Doug McClean
> > jxm156@p...
> > 216/754-1995
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@y...
> > from the same email address that you subscribed. Text in the
> > Subject and Body of the message will be ignored.
> >
> >
> > Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
would address all your requirements. If you designed a single circuit
board that would handle say 10 of these chips, you would only need 7 of
those circuit boards. Beauty of all this is that through multiplexing,
all you current drivers would be taken care of. And if you design your
circuit boards right, they might just exactly fit into the over all
layout. If you did on chip per board and 64 LED's per board, you would
need 64 boards. DO you have 64 students that need a senior design or
extra credit project? <GRIN> I taught school for 15+ years and we
always worked out a way to make these kinds of things happen. Wish you
the best of luck and I wish I were there to co-ordinate the project..
Kind regards,
Leroy
idiggles wrote:
>
> Hi stampers,
>
> My name is Doug McClean and I am looking for a bit of advice on a
> project proposal. Its my job to decide if this project is feasible
> and to draw up a budget for it, so I thought I'd try to draw on this
> group's vast experience [noparse]:)[/noparse].
>
> The project:
> Construct a 4096 independently-addressable element LED display
> spanning an area of about 12 square feet. People must be able to get
> the general graphical impression of the display from a distance of
> 10-15+ feet outdoors (in fair weather, but just for reference to the
> ambient lighting). 120 VAC is available to power the project. As
> much as $2000 could be available for this aspect of the project, but
> minimizing costs is a top priority. The project is for a high
> profile educational institution, we have plenty of EE students to
> draw on and may be able to finagle some part donations. It would be
> desirable if the display could be wiped clean and redrawn
> differently in 5-10 seconds or less through instructions from a
> laptop.
>
> My questions:
> Does anyone have any suggestions for how best to address these LEDs?
> I found a chip from Maxim (the 6953) that can address them in chunks
> of 128 over an I2C bus, I would still need 32 of them, but that
> might not be the worst thing ever because it would keep the wiring
> neat.
>
> Do you think this is doable for $2000?
>
> What sort of LEDs would you recommend using?
>
> Thanks a lot, as always,
> Doug McClean
> jxm156@p...
> 216/754-1995
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and Body
of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/