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DIY LED Array Marquee For Your PC

kdawson posted more than 5 years ago | from the geeking-out-on-the-weekend dept.

Displays 128

An anonymous reader writes "Ever wish you had one of those big LED displays to keep you up to date on e-mails, stock quotes, server uptimes, or weather? Here's a new video tutorial showing how to build your own computer-controlled LED array. You can code your own data feed, and just send it over a TCP socket. This looks like a fun weekend project for someone looking to get started with electronics by building something useful."

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Now... (4, Interesting)

Spazztastic (814296) | more than 5 years ago | (#26577993)

The question is if I can do this and have it run from my car. I put in predefined phrases, and depending on which switch I hit or button, it says them?

Re:Now... (0)

nschubach (922175) | more than 5 years ago | (#26578107)

I only need a bumper sticker that says:
Pass or Move Right

I have thought about others but living in the "Bible Belt", I would have likely gotten my car keyed.

Re:Now... (2, Insightful)

RayMarron (657336) | more than 5 years ago | (#26578183)

Make sure you get one printed in reverse for the front bumper. ;)

Re:Now... (-1, Flamebait)

Anonymous Coward | more than 5 years ago | (#26578847)

Good luck with that, but don't come crying to good ol' Hal when a pack of angry niggers steals your car from you. Our nation would be a better one if we got rid of those dim-witted burr-headed beasts, one way or another.

Yours in Christ,
Hal Turner

Re:Now... (-1, Troll)

Anonymous Coward | more than 5 years ago | (#26581697)

We the Nigger Organization of White Rape (NOWR) take great offense to your assertion sir. Now that we have a Black President this organization (formerly know as Tyrone and the Prison rape niggers) will protest at your house. Our front line of protesters include reformed ex-cons who still have an insatiable appetite for white anus while our 2nd and third wave check for any young females in the vicinity. The NOWR will march upon your domicile at 8pm Eastern Standard Time and we request that you and any equally ravagable kin in your house make preparations and meet our justice with your sweet salty tears.

Tyrone Johnson,
NOWR President and First Rapist

Re:Now... (1)

JCSoRocks (1142053) | more than 5 years ago | (#26578135)

There are actually already license plate frames with little LED displays built in that allow you to do this.

Re:Now... (4, Funny)

Spazztastic (814296) | more than 5 years ago | (#26578233)

There are actually already license plate frames with little LED displays built in that allow you to do this.

Yeah, but it doesn't quite scream "Nerd" as hard as when you built it yourself.

Re:Now... (5, Funny)

houstonbofh (602064) | more than 5 years ago | (#26578455)

Plates are for posers... Get the RIMS! http://customwheel.com/custom_wheels/product_info.php/products_id/1687 [customwheel.com]
Yes, they scare me...

Re:Now... (0)

Anonymous Coward | more than 5 years ago | (#26578715)

those things scream ghetto more then nerd.

Re:Now... (1)

houstonbofh (602064) | more than 5 years ago | (#26579097)

those things scream ghetto more then nerd.

Why discriminate to only white nerds? There can be Ghetto Nerds, too!

Re:Now... (0)

Anonymous Coward | more than 5 years ago | (#26579285)

Who says you gotta be white to be ghetto? Racist.

Re:Now... (1)

nomorecwrd (1193329) | more than 5 years ago | (#26578967)

O... M... G... !!!!

Re:Now... (0)

Anonymous Coward | more than 5 years ago | (#26579051)

lolololol

Re:Now... (1)

Chruisan (1040302) | more than 5 years ago | (#26579099)

The included software allows you to create your own images and send them to each wheel individually or all wheels at the same time as you drive!

Yeah, that makes me feel safe!

Re:Now... (1)

iluvcapra (782887) | more than 5 years ago | (#26579159)

Now we know why the Pacific Coast Highway has so many traffic fatalities...

Re:Now... (1)

Werkhaus (549466) | more than 5 years ago | (#26579555)

Rims are for posers... Get the spokes.
http://www.hokeyspokes.com/ [hokeyspokes.com]

Re:Now... (2, Funny)

sskagent (1170913) | more than 5 years ago | (#26579919)

I was doing ok till I scrolled down and saw Step One.
Step One Rob Bank

Re:Now... (1)

SkyDude (919251) | more than 5 years ago | (#26580293)

So, I should spend $16,000US for wheels on my $2,000US 1997 Dodge Caravan?

One question - will this get me laid?

Re:Now... (1)

MightyYar (622222) | more than 5 years ago | (#26580365)

In general, this depends almost entirely on your standards.

Re:Now... (1)

nizo (81281) | more than 5 years ago | (#26582181)

Probably; certainly someone out there would trade a sheep for those flashy hubcaps.

Re:Now... (0)

Anonymous Coward | more than 5 years ago | (#26582655)

Why worry about getting laid? You've already been screwed.

Re:Now... (1)

morgan_greywolf (835522) | more than 5 years ago | (#26578225)

The question is if I can do this and have it run from my car. I put in predefined phrases, and depending on which switch I hit or button, it says them?

Sure. Let's say you put mount this thing on your car someway, and put a server in the trunk, running off a power inverter hacked into the vehicles 12-volt power. You then run a serial line from there to the microcontroller and wiring to the LED sign, which also must be hooked into the vehicles 12-Volt in someway. The server is hooked to wifi, either adhoc or through a WAP in the trunk along with it.

Then, you have a laptop in the front seat. You get yourself one of those keyboard macro thingies, and hook it to the keyboard port on the laptop. This is set up to send text, as in the example in TFA, to port 6666 on the server. The server then sends the new text through the serial port the LED microcontroller, and voila!

There you go. I just architected your new system at no charge at all. :-D

Re:Now... (1)

nschubach (922175) | more than 5 years ago | (#26578925)

running off a power inverter hacked into the vehicles 12-volt power

No need to hack. They already have DC Power Supplies just for this purpose:
http://www.powerstream.com/mini-itx.htm [powerstream.com]
http://www.short-circuit.com/ [short-circuit.com]

Re:Now... (2, Informative)

petermgreen (876956) | more than 5 years ago | (#26581229)

If you do use a DC psu make sure you buy one that is explicitly designed for use with automotive power. Automotive power while "nominally" 12V has a wide voltage range depending on current conditions (whether the engine is running, if so how fast, if not the condition of the battery etc)

Re:Now... (2, Informative)

Anarkhia (2342) | more than 5 years ago | (#26578435)

Here you go:

http://www.thinkgeek.com/gadgets/car/afe6/ [thinkgeek.com]

I've been thinking about one of these, but am a little worried that I'll end up getting shot or something when I piss off some idiot with a gun in the glovebox.

Re:Now... (1)

SkyDude (919251) | more than 5 years ago | (#26580317)

I've been thinking about one of these, but am a little worried that I'll end up getting shot or something when I piss off some idiot with a gun in the glovebox.

Don't worry, I won't shoot you. My permit is for hunting only.

Re:Now... (4, Informative)

Lumpy (12016) | more than 5 years ago | (#26578465)

Yes but be ready for a ticket and a "fix it ticket" to require removal of said device. Most states make it illegal for a illuminated sign to be in view of drivers on a moving vehicle. TAXI's and delivery cars have a waiver and the signs are not in the line of sight.

Re:Now... (1)

Lord Ender (156273) | more than 5 years ago | (#26580161)

Well then, let's get a howto for making a mechanical sign. You know, like the signs made out of spinning, clacking scrabble pieces they used in train stations before LCD/LED tech (and still use in Europe)?

That would be awesome for both in-car use and the general steampunk feel.

Re:Now... (3, Funny)

Anonymous Coward | more than 5 years ago | (#26578523)

I totally want to do this. So I can verbalize my frustrations with other drivers. Because right now all I have are Brights, Flash Brights, Honk, and Finger. Everything else seems to not get recognized. It would be great to ask people to pleas move out of the left lane. Request blinker changes. And comment on driving skill levels.

Re:Now... (1)

Jawn98685 (687784) | more than 5 years ago | (#26579351)

Yes, the immediate temptation is to mount this thing on our cars, so we can "communicate" with other drivers, who often are badly in need of a little more information. But we all know that are at least as many drivers out there who will act like butt-heads despite being made aware of their condition. Indeed, some will go out of their way to ratchet up their anti-social behavior.

No. What we need is a DIY tool that can forcefully terminate the offending behavior. Then engineering specifics are left to the group for discussion.

Re:Now... (3, Funny)

onkelonkel (560274) | more than 5 years ago | (#26580745)

Caltrops. A big bag of them. Scatter behind your car to discourage tailgaters and those guys with jacked up trucks sporting 2 squillion candlepower fog lights. A bit indiscriminate, and somewhat low tech but definitely effective

Emp Gun. RF generating parts well shielded, waveguide pointing forward from under the hood. Somebody doing 50 in the passing lane? Push the big red button. Oh look, they're pulling over. Funny thing, no turn signals.

Re:Now... (1)

Crudely_Indecent (739699) | more than 5 years ago | (#26578873)

I picked up a kit at wal-mart that is designed for car use. It's a nice case with swivel feet (to allow hanging or standing mount) and comes with a remote control. Best of all, it was less than $20

The handy part of this device is that it has 8 memory locations for user-defined messages. Here are my saved messages.

1. Are you my proctologist? GET OUT OF MY ASS!
2. Got Low Beams? You're blinding me!
3. Your left turn signal is STILL on!
4. Your right turn signal is STILL on!

The other 4 slots remain empty until I come up with something witty to add.

Re:Now... (1)

deroby (568773) | more than 5 years ago | (#26580305)

* Where did the fog go ? (for those eejits that have their (rear) fog-lights on even when it was sunny all week)
* I can't see you ! (for those that forget to turn any light on (*))
* Your braking-lights are broken (can be very surprising when they suddenly come to a stop in front of you)
* Your indicator is broken (for those that switch lane etc without using the indicator... not sure they'd get it though =)

Et-voilÃ, 4 useful messages which all of them I've been willing to pass to my fellow road users at least once in the past couple years.

* : Probably happens more in Belgium than any other country because we have that much of street-lightning making it perfectly possible to drive around without lights. The problem is, although you can see the scenery quite well, those in the scenery have a hard time seeing you... (that is, until it's probably too late)

PS: I hope I have the names more or less right, English not being my native language.

Re:Now... (1)

CaptainDefragged (939505) | more than 5 years ago | (#26580481)

5. Don't tailgate - the end is near!

Re:Now... (1)

Crudely_Indecent (739699) | more than 5 years ago | (#26581801)

I LIKE IT! #5 is now programmed!

Re:Now... (1)

Linker3000 (626634) | more than 5 years ago | (#26581543)

I just bagged a Call Center matrix display unit off ebay for £20!

Mind you, it's 1.5M long!

Re:Now... (1)

PitaBred (632671) | more than 5 years ago | (#26582559)

5. Such a nice shiny car. Too bad the turn signal is broken.
6. They must let just anyone have a license

I'm tapped.

Re:Now... (1)

angst_ridden_hipster (23104) | more than 5 years ago | (#26578949)

Sure, you can, but be careful. Department of Transportation has pretty strict rules about what kinds of lighting you can legally have on your vehicle.

Having a *ahem* friend who experienced problems with law enforcement over a very similar deployment to the one you're envisioning, I'd simply recommend caution.

Then again, the policies and practices of highway patrol / law enforcement in your state may vary. IANAL. This is not legal advice. Etc.

Already exists (1)

Jabbrwokk (1015725) | more than 5 years ago | (#26579383)

You can get scrolling marquee licence plate holders. [skymall.com] This is just the first link I found, I have seen them cheaper at places like Canadian Tire (which will probably confuse 98 per cent of readers here). But they do exist.

Still, making my own would be fun, I could put it up on the wall of my cubicle and do Facebook-style status updates with it. "Jabbrwokk is picking his nose and flicking it at the back of Jeff's head."

Re:Now... (1)

S-100 (1295224) | more than 5 years ago | (#26579993)

Yeah, on eBay for less than $40. Half the cost of the controller alone in the "geek" version from TFA.

Re:Now... (1)

rogeroger (1125533) | more than 5 years ago | (#26582257)

SkyWriter...cool toy from Ideal. I bought one for my daughter in 1981(!) it was a hand-held wand that you would wave to-and-fro, and a row of LED's would leave a message of up to 40 characters scrolling by in mid air. The penultimate night-time road rage instigater

Yes but... (4, Funny)

senatosa (1453155) | more than 5 years ago | (#26577999)

can we get it to synch to Trans-siberian Orchestra's Wizards in Winter?

Re:Yes but... (1)

kiehlster (844523) | more than 5 years ago | (#26578761)

...will it blend?

this just in (-1, Offtopic)

Anonymous Coward | more than 5 years ago | (#26578003)

I HAVE A BONER
i have a boner
poke poke poke

COMMUNISM!

Ever wish you had one of those big LED displays? (0)

Anonymous Coward | more than 5 years ago | (#26578015)

No.

Re:Ever wish you had one of those big LED displays (0)

Anonymous Coward | more than 5 years ago | (#26578365)

You fail at being a nerd.

Re:Ever wish you had one of those big LED displays (1)

mike_93 (1446489) | more than 5 years ago | (#26580001)

You fail at being a nerd.

In that case I'm proud to fail

Re:Ever wish you had one of those big LED displays (1)

onkelonkel (560274) | more than 5 years ago | (#26581807)

Yoda says "Proudly fail is still fail"

Email? Server up time? Please (1)

antifoidulus (807088) | more than 5 years ago | (#26578047)

What will really help this technology take off is if it's able to convert your porn into an LED display. Stick figure porn FTW!

Re:Email? Server up time? Please (2, Insightful)

senatosa (1453155) | more than 5 years ago | (#26578087)

yeah but then you'd have self esteem issues because every stick of the stick figure would be the same size...

mplayer -vo aa to play LED movies (0)

Anonymous Coward | more than 5 years ago | (#26579441)

What will really help this technology take off is if it's able to convert your porn into an LED display. Stick figure porn FTW!

With mplayer you already can play movies on a LED display, just upgrade the microcontroller, make a 80x24 LED display, and use one of the appropriate video output drivers:

mplayer -vo aa movie.avi | netcat localhost 6666
mplayer -vo caca movie.avi | netcat localhost 6666
mplayer -vo bl movie.avi | netcat localhost 6666

aa - ASCII art video output driver that works on a text console. You can get a list and an explanation of available suboptions executing mplayer -vo aa:help

caca - Color ASCII art video output driver that works on a text console.

bl - Video playback using the Blinkenlights UDP protocol. This driver is highly hardware specific.

For more details check the mplayer man page [mplayerhq.hu] .

Um....Actually, No (0)

Anonymous Coward | more than 5 years ago | (#26578145)

I can't say I ever wanted that. Ever.

I've done something similar but more advanced. (5, Funny)

thomasdz (178114) | more than 5 years ago | (#26578153)

I know LEDs are all the big rage now for displays. You see the seven-segment LED displays on calculators. But, while watching TV a year ago, I had an idea... what if I were to somehow connect up a TV to my computer? It took me a couple months, but I finally got it working... yes, a TV screen (well, actually it's not a TV anymore since I had to take out the receiver guts) connected to a computer. Since I use it to MONITOR the status of the various programs running on the computer, I'm going to call this contraption a "Monitor"
I'll make millions!
Also...I was out in my garage the other day cleaning and I found a dead mouse in the corner...and again, my mind is always working... I though...what would happen if I plugged this little guy's tail into the back of my computer, and replaced his legs with little motion-sensing wheels? I'll let you alll know the results when I finish my new invention. I'm calling it the Mobile Organic Universal Sensor Emulator, or MOUSE for short.

Re:I've done something similar but more advanced. (3, Funny)

Aranykai (1053846) | more than 5 years ago | (#26578311)

Shampoo, Is that you?

Re:I've done something similar but more advanced. (1)

martinw89 (1229324) | more than 5 years ago | (#26578319)

Yes, and then I went into *my* garage and had fun building an LED marquee :-)

Re:I've done something similar but more advanced. (1)

Shivetya (243324) | more than 5 years ago | (#26578345)

was more fun reading what you wrote the article

Re:I've done something similar but more advanced. (1)

Scrameustache (459504) | more than 5 years ago | (#26579457)

I was out in my garage the other day cleaning and I found a dead mouse in the corner...and again, my mind is always working... I though...what would happen if I plugged this little guy's tail into the back of my computer, and replaced his legs with little motion-sensing wheels? I'll let you alll know the results when I finish my new invention.

Frankenrat will kill us all, you fool!

/.ed (1)

acohen1 (1454445) | more than 5 years ago | (#26578327)

Hes dead Jim. Anyone have a mirror?

Slashdotted.. (1)

MoellerPlesset2 (1419023) | more than 5 years ago | (#26578411)

But without seeing the article it's fairly safe to assume this involves a microcontroller. I'm guessing an AVR -that's what I'd use, and people have been able to put together TCP interfaces on 'em.

Considering that, I doubt I'd consider this as a good project to 'get started' with electronics. Or microcontrollers even.. AVR's STK500 'starter kit' is a rather nice, if a bit pricey. (I've heard the Basic Stamp system is beginner-oriented. I have no experience with them though)

It's still sounds like a fun kit though.

Re:Slashdotted.. (0)

Anonymous Coward | more than 5 years ago | (#26578743)

An STK500 is sort of overkill for newbies. A USBtinyISP works great for most AVRs, is very cheap, and has some great features.

It's so cute... (4, Informative)

Majik Sheff (930627) | more than 5 years ago | (#26578629)

I remember when I first realized that you could double your row-column population. Then I extrapolated it to its logical conclusion... that you could connect n(n-1) leds where n is the number of control lines. I was so proud! Then in an unrelated search I learned that not only was this an established technique, but it even had a cute name: Charlieplexing.

There's a neat little story here:

http://www.maxim-ic.com/appnotes.cfm/an_pk/1880 [maxim-ic.com]

Low intensity??? (2, Insightful)

spectrokid (660550) | more than 5 years ago | (#26578653)

They have a lot more LEDs than controller outputs and use tricks to multiplex. But this means each LED only is turned on for a few milliseconds at a time. Can you get out a reasonable intensity this way?

Re:Low intensity??? (3, Funny)

Smidge204 (605297) | more than 5 years ago | (#26579025)

Sure, just up the current. The LEDs will be brighter for a shorter duration and it will look the same.

Not sure I like the idea of draining so much current through the uC though...
=Smidge=

Re:Low intensity??? (1)

jhfry (829244) | more than 5 years ago | (#26579347)

Not if you scale it beyond a certain level... as stated in the article, the author feels that this particular arrangement allows for good intensity.

You could, theoretically, use capacitors to increase the intensity.

Additionally, if you wanted to use multiple or a more powerful controller you could do that too.

Like with any electronic design, there are sacrifices to be made to keep things simple.

Re:Low intensity??? (1)

nschubach (922175) | more than 5 years ago | (#26579763)

I was thinking about this. (Also, not being an electrical engineer by any means.) Could you place a relatively small capacitor on each LED to increase the burn time?

Re:Low intensity??? (1)

jhfry (829244) | more than 5 years ago | (#26580563)

Surely you could... might have to make some design adjustments but I can't see why you couldn't use a cap to smooth out some of the (imperceptible) flicker that makes the LEDs dimmer.

However, you would need on cap for every LED... and the result may not be worth the effort. There are surely cheaper ways. Like buying a controller with more outputs, increasing the number of LED's that can be illuminated at the same time, thus increasing the amount of time that can be spent illuminating each LED.

Small version (2, Interesting)

Hogwash McFly (678207) | more than 5 years ago | (#26578655)

My boss gave me a USB-powered LED screen as a Christmas present, aimed as one of those endless throwaway novelty USB gadgets (other one was a whack-a-mole game. It's far smaller than the one in TFA though, about the size of a pack of smokes. Still, it scrolls text and displays bitmaps pretty niftily. The font and configuration files are stored in plain text (the scroll speed was a fun one to tweak) so the option for even-triggered (e.g. server in trouble) scripting is there.

Granted, there's no geek cred from building it yourself, but at least the soft aspect is similar. Now if only there support calls would stop coming in so fast that I had time to play with the thing...

Re:Small version (1)

Yvan256 (722131) | more than 5 years ago | (#26579417)

Do you have a link to that small USB-powered LCD screen?

Re:Small version (1)

Hogwash McFly (678207) | more than 5 years ago | (#26579583)

http://www.dreamcheeky.com/index.php?pagename=product&pid=52 [dreamcheeky.com]
It's from Dream Cheeky, a company that seems to specialise in USB-powered anything...

Re:Small version (1)

Yvan256 (722131) | more than 5 years ago | (#26579825)

You weren't kidding when you said "USB-powered anything".

Pinball games uses the same row-column setup to dr (1)

Joe The Dragon (967727) | more than 5 years ago | (#26578657)

Pinball games uses the same row-column setup to drive lights and read switches.

the video on youtube (1)

markdev (147826) | more than 5 years ago | (#26578665)

http://www.youtube.com/watch?v=SwP3EVPzrkk

Not Slashdotted Anymore! (5, Informative)

compumike (454538) | more than 5 years ago | (#26578677)

Hi all,

We had tuned the www.NerdKits.com [nerdkits.com] site to survive slashdottings with its old PHP backend, but we recently started experimenting with some Django [djangoproject.com] . Django is great as a programming framework, but I suppose we have discovered that our tuning of the server settings isn't quite up to handling a Slashdotting! We've temporarily disabled that stuff so the site is back and running. My apologies for the downtime.

- The NerdKits Team

Next Week on NerdKits (2, Funny)

Len (89493) | more than 5 years ago | (#26578791)

How to turn an old Tivo into a webserver that can withstand a slashdotting!

Re:Next Week on NerdKits (0)

Anonymous Coward | more than 5 years ago | (#26579151)

They have to get the site back up again first.

Re:Not Slashdotted Anymore! (0)

Anonymous Coward | more than 5 years ago | (#26579005)

Wanna bet?

Re:Not Slashdotted Anymore! (1)

bananoid (1282610) | more than 5 years ago | (#26579131)

looks like too many things were disabled

Re:Not Slashdotted Anymore! (0)

Anonymous Coward | more than 5 years ago | (#26579161)

No Internal Server Error Here

The server didn't encounter a internal error or misconfiguration and was actually able to complete your request. We just don't feel like showing you the page.

Re:Not Slashdotted Anymore! (1)

Hobadee (787558) | more than 5 years ago | (#26579215)

500 Internal Server Error

Tell us, does the smoke pouring out of your servers make it hard for you to work on them?

Python fix to make restart easier (1)

leighklotz (192300) | more than 5 years ago | (#26578699)

Put this at the beginning after s is assigned, to reduce the time you have to wait between restarts for old connections to go away.

  s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)

Ah, brings back memories... (5, Interesting)

jtara (133429) | more than 5 years ago | (#26578775)

I wrote the firmware for one of these thingies about 20 years ago. (I did it for a company that was in the electronic sign business - they made those flip-dot signs you see on buses, subways, etc.) I was lucky to have been given pretty-much complete flexibility in the firmware design, including functionality.

We used a Z-80 as the controller. The display panel was built on two identical circuit boards - they could be chained endlessly, though I don't think they ever made a wider model. It was a BIG DEAL getting the component-stuffing machine to place all those LEDs! (This wasn't surface mount, but through-holes.)

Each display panel had a shift-register - one bit per column, and just passed the bits down to the next panel. The CPU banged out bits to the shift register until the row was filled, and then enabled the row driver. Yes, we were careful to avoid refresh rates that could be a problem for epileptics.

They insisted on an asymmetrical case design - the case had a "base" that it could sit on on a desk or other surface, or it could be mounted from a ceiling. Only problem was, if it was mounted from a ceiling, it was then "upside down" and the characters had to be flipped. They were going to put a switch on the back, but I figured they would get support calls from people who wouldn't read the manual, so at my suggestion they put in a mercury switch, mounted at a 45 degree angle. The processor read the mercury switch and flipped the characters if needed.

We used an RCA flat-panel keyboard with a custom overlay. I designed icons for the various effects, and the icons were printed over letters and accessed during programming with the "ALT" key. The icons appeared on screen when in programming mode. There was a simple text-editor, and some icons accepted parameters (for example, transition effects all took an optional transition time parameter) I implemented a simple macro system [macro_name] so that text snippets could be stored and referenced from within messages. You could store multiple messages and select the one or ones to be displayed, or a timer could trigger them.

There was also a serial port through which it could be programmed. I think the idea was that it could be programmed remotely in, say, a store location. I don't know if this was ever implemented, but I vaguely recall that the idea was to send a subcarrier signal on a muzak station (that stores would already have access to) that would be decoded and passed to the serial port.

I never did install one of these in the back window of my car. I certainly entertained the thought, though. :)

I had one of the pre-production samples kicking around for years, and finally discarded it. Yea, I wish I still had that Schelbi Mark 8 too... (Mine was build on a wirewrap board - somebody was selling a kit with a wirewrap board and all the parts).

(Would be interesting to compare the designs. However, the site referenced by the article has been slashdotted...)

Re:Ah, brings back memories... (3, Informative)

jtara (133429) | more than 5 years ago | (#26579011)

To clarify, each display board had a number of serial-in parallel-out TTL shift registers across the top of the board. The parallel outputs went to latches (or maybe the shift registers had latched outputs?) which went to the column drivers. I think there were about 800 LEDs total on the two boards, so quite a bit larger display than this kit! The addressing technique used by the kit would be impractical for this size of display.

It would bang out the bits, latch the outputs, turn on the row driver, and start banging out the next line.

It was BRIGHT and the power supply, even though switching, was hefty. Probably drew as much as a PC power supply.

Re:Ah, brings back memories... (2, Funny)

VorpalRodent (964940) | more than 5 years ago | (#26581131)

Excellent...that way, if the bus ever flipped over, one would still be able to read where it was going to know whether they needed to call a taxi or just keep waiting.
Well done!

How to Use Slashdot for Marketing (0)

Anonymous Coward | more than 5 years ago | (#26579089)

1. buy lots of server bandwidth and hardware 2. have a buddy post a product link 3. have other buddies talk it up

LED Marquees out of HP Printers (0)

screenbert (253482) | more than 5 years ago | (#26579093)

I already have LED Marquees all over my office. I just used this HP Printer hack [kovaya.com] to make them say whatever I want. I setup a rotating schedule so that every 10 minutes it would change the display. It still uses a TCP socket much like this one.

I think it would be cool to juggle [youtube.com] in front GIANT LED marquees.

SIT VIS TECUM (2, Funny)

spaceyhackerlady (462530) | more than 5 years ago | (#26580173)

I got creative with our HP printers a few years ago, trying to see what it would take to get some of our programming team to speak up, or to say anything without being explicitly told what to say. You know the type, I'm sure...

The first person to notice INSERT COIN was my former boss, who spluttered and then demanded an explanation of our sysadmin. Sysadmin claimed total ignorance, but admitted it might be a good idea. I heard this going on and after I regained my composure went in to his office and spilled the beans. And gave him a copy of the perl script. :-)

One of our summer students was terribly confused at first, because he couldn't figure out where to put money in, or how much.

The same printer now says SIT VIS TECUM.

...laura

Cool (1)

British (51765) | more than 5 years ago | (#26579277)

I can have a wall of these LEDs randomly blinking, then my computer room looks like some "secret headquarters" with big monoliths of useless lights, just like in science fiction films of yesteryear. Now only if I could get that sound loop of the "computer beeping" stock audio it would be complete. Maybe a tractor feed printer on a stand, aww yeah.

serial interface (1)

Mike McTernan (260224) | more than 5 years ago | (#26579411)

Shame the TCP/IP stack isn't on the microcontroller. Putting uIP on there, or grabbing bits from my stack (http://www.mcternan.co.uk/MAD/) would be awesome.

I took the lazy path... (4, Interesting)

linhux (104645) | more than 5 years ago | (#26579509)

"Ever wish you had one of those big LED displays to keep you up to date on e-mails, stock quotes, server uptimes, or weather?

Yeah, I used to wish exactly that, but I took the easy (well, I did have to reverse-engineer the serial protocol, but that was fairly easy) way out and went to the hardware store and bought one. It's been serving my team very well since then [f-secure.com] . :-)

Why? (1)

rocketPack (1255456) | more than 5 years ago | (#26580097)

I suppose it has a nostalgic "cool factor" as far as building it from scratch and all, but in terms of money spent and the practicality of the end result, why not just use existing technology? Such as those fancy multi-row mini-LCD displays and hook it up to lcdproc [lcdproc.com] ? I did, and I love it. Crystalfontz 20x4 blue-backlit display with network, temps, weather, slashdot... whatever I want.

I built one of those (1)

heeen (1245200) | more than 5 years ago | (#26580703)

from 10 16x16x(red, green) modules. Problematic was the (theoretical) current required to drive the whole assemblage: 512 * 10 * 20mA = 102 Ampere, at 5 Volt is 512 Watts Although I'm not really sure whether the modules were even able to fully light all LEDs at once, they had a built in shift register. At first I wired them directly to my parallel port and later wanted to wire an Atmega32 to it, but caused a short while playing around, bricking the development board. The modules rest in my basement, since.

Re:I built one of those (1)

heeen (1245200) | more than 5 years ago | (#26580861)

Just checked the Datasheets to the modules (Samsung SLM1606), current supply is 3.2 Ampere per module, which sums up to 160 Watts for a 32x80 pixel display, which puts a PC power supply under some stress.

Hey, what? (1)

hack slash (1064002) | more than 5 years ago | (#26581159)

I'm starting to see more & more DIY hardware articles on this site, articles that are perfectly at home on and more suited to Revision3's Systm, hackaday.com, hackedgadges.com & hacknmod.com - which incedentally is where I first saw this DIY LED array (hackedgadgets).

So is slashdot becomming yet another "Look At What You Can Build If You Have Teh Mad Hacking Skillz!!!11!!" site or what?

Re:Hey, what? (1)

Tokerat (150341) | more than 5 years ago | (#26581705)

Considering many new users on Slashdot have problems with the concept of how a capacitor works, I think they're trying to encourage people to once again learn how to build electronics. Being a geek used to be about soldering and assembly language, but most people these days stop at, say JavaScript. We're going to need people who understand the bits before we can keep inventing new uses for the objects.

fun, but not unique (1)

Eil (82413) | more than 5 years ago | (#26581255)

If you like playing with LEDs, follow the Hack A Day [hackaday.com] blog. At least once a week, there's a post involving home-brew LED projects, some of them quite massive and/or impressive. For instance,

Why? (1)

Seth Kriticos (1227934) | more than 5 years ago | (#26582531)

The first thing I do with newly set up browsers (user interfaces in general) is to disable marquee.. blinking and then ads. I hate those things. They are distracting me and are hell of annoying. So why exactly should I want to put a huge marquee on my desk?

I'm designing an LED TV set - 48", red LED (2, Interesting)

NixieBunny (859050) | more than 5 years ago | (#26582811)

I found a couple hundred big 8x8 matrix LED displays on ebay for way too little money last year, and I'm working on a low-resolution but huge flat TV for video fun at Burning Man this summer.

But I'm going with a standard video signal such as your DVD player makes, so it will display shades of gray for realistic reproduction of video images.

It's a bit tricky to make a TV display out of LEDs, but I found that using a couple dozen FPGAs makes the job a lot easier. Pulse width modulation provides the brightness control per pixel.

It should be a lot of fun when completed. I';ll post photos.

This is the essence of hacking (1)

SpacePunk (17960) | more than 5 years ago | (#26582917)

Making something that's been around a long, long, long time, and acting as if it's 'new' or 'improved'.

Wake me when someone does something impressive, and get off my lawn.

DIY? (1)

drmitch (1065012) | more than 5 years ago | (#26582989)

So the question is, if you're buying a MCU kit from a company, how is this a DIY project?
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