Interactive LED wall art (understood, and under construction)

[Langer]

Hello again all.

I'm taking on yet another project, one I couldn't resist after seeing the video below:
YouTube Link (http://www.youtube.com/watch?v=IkmpIXd9Q90)

After hunting around on the Evil Mad Scientist Laboratories website I found an example circuit diagram and building instructions.

I was hoping that someone could help me make some sense of the diagram below. Perhaps put it into lamens terms for me. I have a bit of hobbiest level electronics experience, but I've never taken on a project like this before.

Here is the circuit diagram, which I understand for the most part, I was just hoping someone could offer up a wiring diagram to help me better understand.
http://img.photobucket.com/albums/v60/Langer/misc/TableDiagram-2.jpg
The project called for 16 of these circuits in a 1-D topology (whatever that means)
http://img.photobucket.com/albums/v60/Langer/misc/TableDiagram-1.jpg

They took some pics of the circuit as well - simple enough, I just have a bit on confusion identifying which wires correspond with which:
http://img.photobucket.com/albums/v60/Langer/misc/TableBook-5.jpg
http://img.photobucket.com/albums/v60/Langer/misc/TableBook-4.jpg

When complete it should start to look something like this (hopefully I can do a better job of wire management).
http://img.photobucket.com/albums/v60/Langer/misc/TableBook-8.jpg

Any help that you lot can offer would be a great benefit, I don't have much experience with making my own IC circuits... outside of some basic arduino projects.

Thanks in advance.

[evil-98]

thats one big project, id love to have that as a table

good luck, and i will help where i can, thought i cant make sense of the
diagram i will get one of my co workers to digest i for me .

:up:

[BreeSpree]

If you make one, that looks nice, I would like to buy one myself if anyone sold them... Looks a very ambitious proeject, especially there will not be much guides to tell you how to do it. When your done, maybe paint it black, instead of a yellow in the video?

[Langer]

Thanks guys, I spent some time today examining the circuit and I now grasp it in it's entirety (almost... I'll ask these questions tonight after I post my diagram). Thanks for those who lent a hand.

I'm ordering the parts to begin construction today, should be able to throw it together in <1months time.

My plan is to use frosted glass so that you don't see the circuits and so you'll only see the glow of the lights.

I'd be interested in fabricating these for purchase if there is enough demand.

[BreeSpree]

Yea-Uh... I want one to hang on my wall, maybe cover it with a few posters, so people walk past it and :shocked: OMG the wall is glowing. Would also want one, as I need a new computer desk. One that glows would be nice...:up:

[Junimrox]

very interesting, i understood the diagram, but ~1.1 volts leds? i've never seen them, only 3.0-3.7 volts... do you guys know ehrer to find them? could I use other power supply?

[Langer]

@Junimrox - From what I recall about voltages +15 > -15 = 30... giving about 2volts to each LED... which still seems low to me.

Okay, I've redrawn the diagram to be more user friendly (at least I can understand it better now).
click for big
http://img.photobucket.com/albums/v60/Langer/misc/wirediagram-LOW.jpg (http://img.photobucket.com/albums/v60/Langer/misc/wirediagram.jpg)

I have a few questions for the electronic experts among us:
1 - On the Chip there are V+ and V- pins... what voltage do I apply to these when using 15V to power the LEDs?

2 - There is also a demand for a second power source of -15V, what does this mean? How do I get negative voltages?

3 - Can anyone suggest some inexpensive power supply units that can power the +15V, -15v, and the mystery IC voltage pins?

4 - Can anyone see any problems with my diagram, or is it all tickity-boo?

5 - For circuit number 1 in the 16 circuit series, do I simply ignore the "IN FROM NEIGHBORS" section? the same question for the last in the series, do I ignore the "OUT TO NEIGHBORS" output? Or is there something that I need to take into account?

THANKS so much in advance, for helping me realize this vision.

[kraifect]

I deffinitly would not have the slightest clue on where to begin here, nor patience.
I give you big credit if you finish this, BIG credit.

[Langer]

I always finish what is started... jumanji had a big effect on my apparently. Haha.

To help a bit further here are the specs of the IC's I'll be using:

LF347
Gain Bandwidth: 4 MHz
Channels: 4 Channels
Input OutputType: Vcm to V+, Not R-R Out
Slew Rate: 13 Volts/usec
Supply Min: 8 Volt
Supply Max: 36 Volt
Offset Voltage max, 25C: 10, 5 mV
Supply Current Per Channel: 1.8 mA
PowerWise Rating 2: 450 uA/MHz
Internally trimmed offset voltage: 5 mV max
Low input bias current: 50 pA
Low input noise current: 0.01 pA/SqrtHz
Wide gain bandwidth: 4 MHz
High slew rate: 13 V/µs
Low supply current: 7.2 mA
High input impedance: 1012
Low total harmonic distortion: <=0.02%
Low 1/f noise corner: 50 Hz
Fast settling time to 0.01%: 2 µs

[Swatrecon_]

Instead of frosted glass, I would use a black mirror, so you couldn't see anything, but faint lights shining through. Maybe not completely mirrored though. Like 35%

[Langer]

I've been thinking and I love the idea of hanging it on a wall (+1 for BreeSpree, thanks mate!)... I'm thinking about exposing the LEDs and hiding the circuits.
I like the idea of using perforated aluminum -holes filled with LEDs of course- to showcase this creation.

Slight change as per the suggestions of Mohonri over at [H]ard Forum.

http://img.photobucket.com/albums/v60/Langer/misc/wirediagram-R2-LOW-1.jpg (http://img.photobucket.com/albums/v60/Langer/misc/wirediagram-R2.jpg)

[Langer]

Another revision....1-step closer.
http://img.photobucket.com/albums/v60/Langer/misc/wirediagram-R3-LOW.jpg (http://img.photobucket.com/albums/v60/Langer/misc/wirediagram-R3.jpg)

[Barrman]

Hi there! very interesting project you got here. As far as the V+ and V- pins on the opamp you will need to connect V+ to 15V and V- to -15V. It looks like some one has already shown you how to take a 30V supply and split it into +15 and -15 just be sure the resistors you use are fairly high (mega ohm or so) in value or they will draw a lot of quiescent power. Also be sure that if you do that split configuration that you tie the virtual ground at the center of the two resistors to an actual ground (case/psu) so it can sink current properly. If you let it float things will get funky.

Sorry I dont have time to check your diagram but the data sheet gives you a pin out and the circuit is not to complex so I think you can figure it out.

Good luck