# Please provide some help-Driving LEDs to form patterns

Thread Starter

#### rocksolid

Joined Jun 6, 2015
12
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.

#### shteii01

Joined Feb 19, 2010
4,644
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.

#### djsfantasi

Joined Apr 11, 2010
8,389
Twenty LEDs won't fit in a square pattern. You need either 16 or 25 (4x4 or 5x5).

I have questions on your corner to corner move, but first have you programmed? This is screaming for a microprocessor solution. Otherwise, it gets very complicated. Especially random mode.

Given that you are not a tech person, this likely would be a very difficult project. What is it for?

#### shteii01

Joined Feb 19, 2010
4,644
Twenty LEDs won't fit in a square pattern. You need either 16 or 25 (4x4 or 5x5).
The physical layout might work in the "chess board pattern".

#### djsfantasi

Joined Apr 11, 2010
8,389
The physical layout might work in the "chess board pattern".
Don't think that fits either. I get squares bounded by either either 13 LEDs or 25 LEDs (5x5 or 7x7). Guess I need the TS to clarify his pattern.

Thread Starter

#### rocksolid

Joined Jun 6, 2015
12
Thanks for responding everybody. It is a project I am working on for a client so I can't go into details, sorry. It does not have to be 20 lights. He is looking for a piece of nylon that is sqaure and then he wants LED lights under the nylon. Then when he turns the LED on you will be able to see them from the top of the nylon and he wants the lights to move around. He is thinking a nylon piece that is 3 feet by 3 feet or so. It was suggested to use SMD SINGLE COLOR TAPE LIGHT and a DMX controller.

#### shteii01

Joined Feb 19, 2010
4,644
SMD SINGLE COLOR TAPE LIGHT and a DMX controller.
I guess.
Are the lights on the tape individually controlled?
If not, then you can forget about doing random pattern.

Since you are talking 3'x3', this beginning to look like $500 to$3000 price tag project. Good luck.

Thread Starter

#### rocksolid

Joined Jun 6, 2015
12
After doingmore research it seems I need DMX programmable LED strips. Can anybody confirm?

#### djsfantasi

Joined Apr 11, 2010
8,389
Do you have a budget? Going DMX could cost cost in the vicinity of $1,000... The strips are between$100-$200 and to make a square, you might need 4-5 strips (based on one strip I found online). And controllers are several hundred apiece Not a DMX expert, but a while ago, researched the technology for my animatrons. #### shteii01 Joined Feb 19, 2010 4,644 you might need 4-5 strips (based on one strip I found online). How wide are those strips? I would think they would need more than 4-5 strips for 3 feet square. #### djsfantasi Joined Apr 11, 2010 8,389 How wide are those strips? I would think they would need more than 4-5 strips for 3 feet square. They were 16 feet long. Thread Starter #### rocksolid Joined Jun 6, 2015 12 I don't have a budget, but we are building a prototype and we relly need to keep the dollars low. I was hoping to do this all for under 100 bucks. #### shteii01 Joined Feb 19, 2010 4,644 I don't have a budget, but we are building a prototype and we relly need to keep the dollars low. I was hoping to do this all for under 100 bucks. You will have to forgive me for: LOL #### shteii01 Joined Feb 19, 2010 4,644 They were 16 feet long. I meant width. If you have 3 foot square, that is 3 feet on each side, 36 inches. If the strip, for example, is 2 inches wide, then you would need 18 strips. But! The strips will be positioned diagonally... so some strips will be short, some will be long in length. #### korchoi Joined Jun 5, 2015 59 DMX is Professional-style and used in final products.Most things you can buy with DMX cannot be powered by batteries.Also, As fantasi said, it is not cheap. to do your 100$ animated led matrix, you will need to design you own led controller with digital logic.Pretty easy with microcontrollers.
You will need 3 main things:
-knowledge on basic electronics
-knowledge on microcontrollers
-LED's, Resistors, a Microcontroller and its respective programmer.Also, a breadboard.
An easy and cheap microcontroller platform would be the arduino uno. It is very easy to get stuff working.
the microcontroller in it can be powered by a coin cell(3V) or Lithium ion(3.7V), but again, you need to know electronics and microcontrollers to do it.

#### djsfantasi

Joined Apr 11, 2010
8,389
This was just for an estimate. However, the width of the strip is irrelevant. What is relevant is the distance between successive LEDs. Which is somewhere between 1.5" and 2". As the strip is routed back and forth across the square, the distance between LEDs in each row (or column, depending on how you see it) should be the same distance as the separation on the strip. Say it's 2". A 16 foot strip would make 5+ rows (16/5). At a separation of 2", this would occupy at least 10"x3'. You'd need 4 strips to fill the entire 3'x3' area.

#### Brevor

Joined Apr 9, 2011
297
I am not a tech person so you may need to talk to me like a 5 yr old.
I am working on for a client so I can't go into details
I was hoping to do this all for under 100 bucks.
Please understand I'm not trying to be offensive, but I suggest you give up now. Because of the constraints listed above I don't think it is possible.

#### Bernard

Joined Aug 7, 2008
5,788
Can you stand 3 in spacing & 3 in in from borders? That would be 121 LEDs, 11 on sides. 11 X buss bars & 11 Y buss bars with a LED connected at each intersection. All Xs ( anodes) low, all Ys ( cathodes ) held high. Any one led can be lit with one X low & one Y high. Advancing strings along X or Y is easy, Along dionagonal -out of my hands.

Thread Starter

#### rocksolid

Joined Jun 6, 2015
12
Please understand I'm not trying to be offensive, but I suggest you give up now. Because of the constraints listed above I don't think it is possible.
I have created products for clients that I did not know anything about. If people listened to people like you we would not be flying through the air. I thought I might find some " Free" thinkers here. Instead of telling me it can't be done how about giving me some options. Maybe tell me that for 100.00 I could do ABC or just think outside of the box and figure out how I could make this happen. I have already seenDMX led strips for around 40.00 even though I have to order it from another country. There are ways to make things happen if you go outside of your usual thinking.

#### djsfantasi

Joined Apr 11, 2010
8,389
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.

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

Your combination of constraints is daunting. Even if you got the DMX strip for \$40.00, how want would you need. In my example, you'd need 4. No budget left for a controller.

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

Bernard's idea is a good one! However,it will need supporting circuitry in addition to a microprocessor and programming. This all adds up in cost and technical difficulty.

A device could be built with discrete logic, but separate logic would be necessary for each pattern and then we'd need a logic module to switch between patterns.

If you really want to think outside the box, a non-electronic solution might be imagined. Somethink akin to a player piano

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.

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