Hello,

You might want to have a look at henne's site.
There you can find a DMX circuit to drive a led matrix:
http://www.hoelscher-hi.de/hendrik/english/matrix.htm

Bertus

 

Ok, what do you want the LED spacing to be? Left to right and top to bottom. I assume you want a checker board pattern, with an LED in the center of every square.

Yes, a checker pattern would make the most sense for this project.

BTW, is this single color LEDs or does your client like the idea of multi-colors?

Single color - red

You do realize you'll need a DMX controller. They are often more expensive than the device. And they also need programming

If that is the only way to make this happen then no problem

Being a free thinker and thinking outside the box certainly can come up with solutions that may appear impossible to others. But not always. No matter how many women are put on the task, having a baby in half the time ain't gonna happen.

LOL,
thank you for taking the time to break things down. All I am looking to do is you take this piece of nylon shaped in a square that has led lights in a box pattern. You press a button and the lights blink on and off randomly one at a time. You press the button again and the lights now go through a chase sequence. I thought this would not be very hard to make but I guess I was wrong. It does not have to be led lights but I don't know what else can be used to create the same effect.

 

LED lights aren't the limiting factor. One is the size of the square. With an LED spacing (which you haven't specified yet) of 3", you'd get 12 LEDs on a side or a total of 144 LEDs. Driving that many individually is going to take a bit of clever thinking.

Under $100 is tough, too. You can get a microprocessor for a few dollars, but then you need experience in building it from scratch. An Arduino can he had for $25. But neither can drive a sufficient number of outputs without additional circuitry.

It can be done. It's not impossible. But there is a certain skill level required. Your self assessment does not appear as if you are comfortable with that skill level.

As Bernard suggested, I'd make a 12x12 (assuming 3" spacing) LED array, all cathodes is a row connected and all anodes in each column connected. Driver circuits would connect to each row and column. These circuits (transistor based) would connect to the microprocessor pins or shift register outputs.

Additionally, connect a push button to a pin on the microprocessor.

Then, I'd write the code to do what you described: process the pushbutton for mode, randomly light the LEDs, display a chase pattern (the beauty of the microprocessor is as long as you have available memory, you can add patterns), etc...

Remember, any given set of constraints does not necessarily gave a solution.

• A number from 1 to 10
• An even number
• A number less than 2

 

I like to think inside the box.
Each contact inside the box is wired to a corresponding LED.
Sliding puck or ball is wired to battery positive.
Tip the box diagonally to get those lights to go from one corner to the other in a row.
Bounce the box to make them go on randomly all over this square one at a time.

 

Again, what spacing ? Is sweeping L to R or back & fourth rather than diagonally acceptable?
If so $ 100 might do with all discrete IC's, assuming just the two patterns.

 

So..... I am looking to get a set of flat LED lights to go on when I want them to. I was told I may need to use a DMX driver. So here is what I want to happen. I want to make a flat set of 20 led lights in the shape of a square with the lights filling in the square. I want to get those lights to go from one corner to the other in a row so it looks like it is moving, so I need the corner light to go on and then the next one diagonal to go on as the first one goes off and so on, so it looks like it is moving from one corner to the other. I also want to make these lights go on randomly all over this square one at a time. I would like to be able to turn a switch or click a button so in position 1 it would do the line pattern and in position 2 it would do the random lights. Can I make this happen and can I do it using a battery power. Also I need to keep this simple and cheap if possible. I am not a tech person so you may need to talk to me like a 5 yr old. Thanks.

There are some addressable LED products from Sparkfun and Adafruit that might be useful. The ones I've seen are RGB, not single color.

Not much has been said about brightness or grid size. A 1m square divided into a 10 X 10 matrix of 10cm squares for example would almost certainly require more luminous flux for each square than any single discrete LED could provide unless it were on the order of several watts. Diffusion to balance the light across the surface of the square can require some depth and/or specialty materials.

You mention nylon as a covering material. Is this a sheer fabric or what? I imagine what you're trying to make is for theatrical effect such as a one time fashion shoot or a short-run show event. If it's intended for a more durable application such as an art installation or a dance club, some of the material choices would be different. The intended purpose could also affect the control method since a display that's briefly seen would not have to have truly random patterns.

We've provided some information about resources and constraints. You need to come up with a project proposal that contains a much higher degree of specificity than the broad conceptual ones provided so far.

 

First off, thanks again to everybody for giving some great options and ideas. I don't know what a lot of it means, but can learn or find somebody to explaine lol. The great thing about this project is I don't have any rules. The question about spacing has come up and I am guessing that means how far apart the led's are from each other......well I don't know, isn't that great? In my mind I was thinking each LED would be about 2 or so inches apart from each other but it does not have to be. Having no rules means I get to write the rules, with your help. I just know the finshed product needs to basically look like a square that is about 3 feet by 3 feet and have leds under it so when they light up it can be seen from the top. I spoke to my client and they are looking to build a baby toy or tool, so the idea is a mat that a baby sits on and goes after the lights when they get turned on. I think it may be to see how good a babies reflexes are or to see how well there eyes work, either way that is what they are looking to do. Does that help?

 

So, it's a disco floor for todlers. It's going to have to be waterproof. The enclosure alone would cost several hundred dollars in single quantities.

I'd prototype it with a microcontroller and commercial display RGB modules, then let the client and his budget reduce the features, colors, patterns and brightness to what they want and can afford.

 

I disco floor, that's funny and yeah I guess accurate.

 

I think the best advice at this point is for you to make a smaller prototype. Perhaps 6"x6". Some none commercial none production parts already been suggested:
-Arduino Uno (5 volt system, might not have enough pins, may need multiplexer), a cheap clone is about 9 dollars.
-Arduino Due (3.3 volt system, has 50+ pins, should be enough for small prototype)
-hobbyist led and led strip control boards/drivers from SparkFun, Adafruit, etc.

There will be great urge to power led from the microcontroller (where microcontroller provides the current to the led). Don't. Microcontrollers generally do not have ability to provide a lot of current, even your smaller prototype will have lots of led, they combined will need a lot of current. Don't source current from microcontroller. Source it from external power supply.

 

Maybe I could use these.

https://www.sparkfun.com/products/12027

 

Are we talking led that need 2-3 volts to turn On?

For your random pattern, you will need to turn On and Off led individually, which means individual control for 20 led... which makes things complicated very fast.

Really? - I'd go for a 5x4 matrix drive.

There is an off the shelf matrix message display for 7x9 LED modules, but I don't remember the make/model.

They're serial data so you can daisy chain as many of the chips as you want the display to be long.

Then all you need is a small micro to generate the data stream.

 

Maybe I could use these.

https://www.sparkfun.com/products/12027

That looks good. Add microcontroller and you are looking at 100-200 dollar price tag, i think.

 

That looks good. Add microcontroller and you are looking at 100-200 dollar price tag, i think.

This could be the chip I was thinking of:-

http://www.adafruit.com/products/453

 

This could be the chip I was thinking of:-

http://www.adafruit.com/products/453

tell it to rocksolid.

 

That looks good. Add microcontroller and you are looking at 100-200 dollar price tag, i think.

I don't know. The engrish in this thing's datasheet seems shady.
Beyond shady engrish, the serial protocol used in this thing is a clockless fixed-rate protocol, similar to the one used on the gamecube and n64 controllers.
Long story short, it is not compatible with i2c, spi or uart(no easy communication to arduino).

 

I don't know. The engrish in this thing's datasheet seems shady.
Beyond shady engrish, the serial protocol used in this thing is a clockless fixed-rate protocol, similar to the one used on the gamecube and n64 controllers.
Long story short, it is not compatible with i2c, spi or uart(no easy communication to arduino).

I think they have sample connection guide and sample code on the website.

If you are right about comms protocol, they must be bit banging using digital i/o pins.

 

I think they have sample connection guide and sample code on the website.

If you are right about comms protocol, they must be bit banging using digital i/o pins.

Oh,bit-banging.If this LED strip is well-known, there might already be a library for arduino somewhere.No sweat.

 

Any ideas on LED selection yet. Assuming 20 mA LEDs, 121 or 144 LED's, about 20 IC's will cost around US $ 51.
average IC @ $ .75 & LED's max $ .25 ea. 74AC32 selected for X axis OR LED drivers as each output rated @ 25 mA. 6 ea. @ $ .56 Digikey
Y axis 3 of the OR's & 2 ULN003's, 500 mA drivers. So far can be used with micro controller,uC, or up to 12 more IC to complete project.
Other IC's might be, 4- 4017's, 4- 555's, a few NAND's, OR's. & NOT's & some resistors & caps.
A layer of one inch cotton batting over the LED's makes an interesting light difuser.
An answer to post # 25 would be nice.
With higher current LED's, add 2 more ULN2003's & some name changes.

 

I used to have a HoMedics LT-300. It may be a good starting point for whatever you're doing.