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Large Scale LED controller

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VizualXTC

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Ok, I already know this is WAY over my head already, but I want to build a light display using multiple LED's. The problem I am facing is I can't seem to find any controllers that interface with a PC that will tell me how many LED's they will drive. They tell me how many channels they have, but never how many LED's the controller will drive per channel. Is there a universal amount of LED's able to be run on say a 16 channel controller? Any help would be very appreciated. Also, if anyone has a schematic of a large scale controller, or even a small scale controller that can be PC based, if you are able and willing, I would love one. I know a little about electronics but I have a LOT more to learn. If it's not the most difficult schematic to follow, I might be able to build one, and save myself a ton of green. Thanks for any help you might be able to lend.
 
Ok, I already know this is WAY over my head already, but I want to build a light display using multiple LED's. The problem I am facing is I can't seem to find any controllers that interface with a PC that will tell me how many LED's they will drive. They tell me how many channels they have, but never how many LED's the controller will drive per channel. Is there a universal amount of LED's able to be run on say a 16 channel controller? Any help would be very appreciated. Also, if anyone has a schematic of a large scale controller, or even a small scale controller that can be PC based, if you are able and willing, I would love one. I know a little about electronics but I have a LOT more to learn. If it's not the most difficult schematic to follow, I might be able to build one, and save myself a ton of green. Thanks for any help you might be able to lend.

Hi! Welcome to the forum.

I think you mostly need to define your terms first. When you say "controller", are you talking "lighting controller" as in stage lighting, or room lighting, or some other thing? Do you have any links/model names etc which could help us know what kinds of things you're looking at?

Some other things it would be good to know in order to help you:

How many LEDs will be in the display?

What kind of display is it? i.e. random single blinking lights, scrolling message, random blinking groups of lights, etc.

How would you like to control it? From a PC or microcontroller?

To determine what you can run per channel, you need to look at the output voltage and amperage available on each channel.

Anyway, just hoping to get some more information so that we have a place to start.


Torben
 
I apologize for being vague. I work in a dance club, and I am planning on building a large 'sign' aprox. 20x5 feet in dimension. In the middle I will put the name of the club (in LED's) aprox. 4x2 feet and around the outsides I want randomly blinking (fading in and out) LED's. In effect, it will have the name of the club surrounded by blinking stars. I'm still deciding if I want the name outlined, or a full array. If I do a full array, I will want to be able to control from my PC or laptop certain ways the LED's will act. (i.e. change colors if I use RGB, or a quick scroll of fading LED's to signify a shine or 'bling' effect) If I end up outlining, I will only need to control maybe a color change, or possibly a chase style outline. But I want control via my PC as to be able to change it on command. I figure I will need up to 1000 LED's with the outline, and many more if I do the array. Thanks for any help you can lend. Like I said, I am pretty new at this, but I am a 'do-it-yourselfer' because I LOVE to learn new things.
 
OMG that will be very hard & sacrificing lot of time & work.Better buy it from a signboard manufacture.But it will almost cost highly.

I have done LED sign boards (with user defined characters) but not that huge size.

If you need to display only your dance club name then I'll suggest you to make letters from the LED's & control them via a control circuit (can do without any micro controllers).

When it comes to LED matrix system it will be too complicated.
 
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If needs be, I will just make the outline stable and have the stars blink using micro controllers. I would prefer to do it the way I want (obviously) but will sacrafice if needs be. Either way, I would like to figure out HOW to do it because I am not really on a budget. I know it's possible, just need to know if it's worth it.
 
You might be interested in the way the Christmas lighting people do their displays. They use cascaded serial in parallel out shift registers. A single bit from a micro shifts the pattern into the registers, the pattern is then used to illuminate the LEDs. One such chip is the 74HC595 Shift Registers With Output Latches. Each will control 8 LEDs so you will need a lot of them.

I would hook a string of these chips to each bit on a port. Eight strings of 16 595s would control 1024 LEDs.This will let you blink the lends in any pattern.

To dim/fade the LEDs you need to do pulse width modulation. In short to do PWM you turn the LED on and off quite fast and to the eye it seems to be on but not at full intensity. The on-off ratio of determines brightness.

Google for "Olsen 595 controller" or "595 Christmas". Since you will be running LEDs you will only need a resistor and a LED connected to the outputs on the 595s. If you want more power then the 595s deliver you can use a transistor to power each LED. There may be a version of the 595 with more drive but I can not remember the number. Anyone?
 
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Some "sinking driver" versions of the 74HC595 are the Micrel MIC5821 and the Allegro A6821. Both, if I recall correctly, will 'sink' up to 500 ma at 50v.

Mike
 
Google for "Olsen 595 controller" or "595 Christmas". Since you will be running LEDs you will only need a resistor and a LED connected to the outputs on the 595s. If you want more power then the 595s deliver you can use a transistor to power each LED. There may be a version of the 595 with more drive but I can not remember the number. Anyone?

I looked at a few sites describing the Olsen 595 Controller and it looks pretty interesting. One question I do have about this. (Again, a Noob ?) If I were to use RGB LED's, I would have to triple the amount of 595's correct? They all use the same Cathode, but the anodes would have to be on separate ports. Although this really isn't a problem, per se, just a lot more work. (probably worth it in the end tho)
 
I looked at a few sites describing the Olsen 595 Controller and it looks pretty interesting. One question I do have about this. (Again, a Noob ?) If I were to use RGB LED's, I would have to triple the amount of 595's correct? They all use the same Cathode, but the anodes would have to be on separate ports. Although this really isn't a problem, per se, just a lot more work. (probably worth it in the end tho)
Exactly.

What you want to do is simple in nature for a micro controller project, but the scale is so large that it will get ugly if you are not careful. Start small with a pair of 595's and a 18F pic to get a feel for it on a small scale. Figure out if you need transistors to make the LEDs brighter learn a little about coding the program. FWIW I found 74HC595's at Newark for 20 cents (SMD) or 23 cents (DIP) in 200+ quan. The big cost is going to be the 1000 3 color LEDs.

After looking at what you need to do buying a ready made unit may sound good.
 
Evil Mad Scientist Laboratories - Peggy version 2.0

This a customizable 25x25 (625) LED sign board kit ($95, less LEDs, another $50-$100+).
Uses Atmega168 (same as Arduino), completely open source. Every LED is individually controllable, and can be any color (mix or match). Can even do 14x14 RGB...

Posted this link, as it should be useful to see how to control a lot of LEDs, and just getting several kits would save you a huge amount of time and money. I saw this last week, and thinking about getting one, just for the Conway Life demo (always liked that on the computer, one of my first assembly language projects on the Commodore 64).
 
You can put any color LED anywhere in the Peggy array, but Peggy doesn't use multicolor LEDs.

How much current do you plan to use per LED?
 
You can put any color LED anywhere in the Peggy array, but Peggy doesn't use multicolor LEDs.

How much current do you plan to use per LED?

Not very much current at all. Maybe 1.5v at the max power. I work in a dimly lit club and I don't really need my sign illuminating the whole thing. LOL!

I actually changed my mind a little bit. I think instead of using the RGB (which would be awesome, but overkill for my application) I am going to, instead, go with UV LED's because blacklighting is very prominent in all aspects of my club, maybe some blue, and white ones as well. This has changed my design ideas a little bit more.

As far as the name in the middle, Is it possible to run them ALL off a single port on the 525? In essence, making the PC (or micro controller) think of them all as a single LED rather than 1000 individual diodes? Then I just have to mess around with the dimming on the 'stars' which I understand can each be run off a micro controller to do the task of dimming. Is this correct?

Thank you all for the help you are giving. Without you guys, I would be in WAY more over my head than I already am. HAHA!
 
Also, these are the types of LED's I'm planning on using.

**broken link removed**

Not to be a downer but that might not be a great idea--UV LEDs don't look all that bright but if you look straight into them you can get a lot of light focussed on the retina which doesn't provoke a blink/avoid response and doesn't trigger the iris to contract.

Although in a club situation I'm thinking it might be mounted high enough that nobody can look straight into the display. Is that correct?

There are some interesting notes on this page.

Putting a bit of fluorescent paint on the tip of each UV LED seems like a neat way to both make it look cool and make it safer.


Torben
 
Not very much current at all. Maybe 1.5v at the max power. I work in a dimly lit club and I don't really need my sign illuminating the whole thing. LOL!
Current is measured in amps. A PIC IO pin can sink or source .025 amp aka 25ma. Adding a cheap transistor like the 2n2222A will provide up to about 800ma, depending on which 2n2222A you use.
As I suggested earlier you need to play with this on a small scale, it will help you figure out what you want to do.
As far as the name in the middle, Is it possible to run them ALL off a single port on the 525? In essence, making the PC (or micro controller) think of them all as a single LED rather than 1000 individual diodes? Then I just have to mess around with the dimming on the 'stars' which I understand can each be run off a micro controller to do the task of dimming. Is this correct?
If you mean 74HC595 then the answer is yes and no. You can use a single output bit. But you need to use that bit to trigger several transistors that can drive short strings of LEDs.
 
Well, there are times that people would be at the same level as they are, but not very often. I will look into the paint idea. Last thing I need is to start messing with people's health. LOL!
 
Current is measured in amps. A PIC IO pin can sink or source .025 amp aka 25ma. Adding a cheap transistor like the 2n2222A will provide up to about 800ma, depending on which 2n2222A you use.
As I suggested earlier you need to play with this on a small scale, it will help you figure out what you want to do.

My bad. I know that. I was thinking something else. I don't know the amperage right now, basically have to figure out how many LED's I plan on using, and such.

If you mean 74HC595 then the answer is yes and no. You can use a single output bit. But you need to use that bit to trigger several transistors that can drive short strings of LEDs.

Yea, I meant the 595. It was early in the morning when I posted that last post and was a little out of it. Sorry.

I am currently looking for some software/freeware that will let me simulate a circuit so that I can try all this out without spending a lot of their money up front. So far, I haven't found anything that looks like it will do what I want to do.
 
I am currently looking for some software/freeware that will let me simulate a circuit so that I can try all this out without spending a lot of their money up front. So far, I haven't found anything that looks like it will do what I want to do.

Try LTSpice/SwitcherCAD III. And no, I don't work for Linear. But it's a free-to-use circuit simulator and it's probably the best you're going to get for the price.

Does the star field need to be an unbroken grid of LEDs or would randomly placed LEDs on a black background work?

How many individually controllable groups of LEDs do you want?

Do you want any particular effect for the club name or should it just be fully lit the whole time?


Torben
 
Try LTSpice/SwitcherCAD III. And no, I don't work for Linear. But it's a free-to-use circuit simulator and it's probably the best you're going to get for the price.

Does the star field need to be an unbroken grid of LEDs or would randomly placed LEDs on a black background work?

How many individually controllable groups of LEDs do you want?

Do you want any particular effect for the club name or should it just be fully lit the whole time?


Torben

The star field is going to be randomly placed LED's. The only time I might have them connected in any way is if I decide to put a 'shooting star' in there somewhere. I haven't decided. As far as the club name, originally I wanted to be able to change it's color, and maybe make it look like it's 'gleaming' but I am not nearly advanced enough to do that, so I will keep it fully lit.

One more thing, I don't know if you guys really want to go this far into it, but what if I were to get the club name to blink with the beat of the music. What circuitry would I need for something like that? I have seen a lot of threads on this board about sound activated lighting, but they all offer information on connecting into the speaker leads, or a 'clapper' style switch. I want an independently operated switch controlled by a selectable (hopefully with a pot) frequency or sound level. How difficult would this be? HAHA! My ideas mutate like a virus. Chalk it up to ADD.

If I were to set it up so it blinks, I would have it on a switch so I could have it on, off, or blink modes. (that's the easy part of the endeavor) Thank you guys again for all the help you have given thus far, and for any information you can lend in the future. :)
 
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