I am looking for advice on the best method to randomize 100+ LED's for a retro styled mod. Any ideas on the best approach for this? The LED's will be in a grid pattern with a few embedded activity LED's for the HDD and CD/DVD and LAN so there will be 11 rows and 11 columns of LED's with a few LED's mixed in that don't get controlled by the randomizer. Oh, all LED's will be red except the fixed source LED's which will be Bi-Color Red/Blue, Make sense? Will look something like this: o = Randomized LED x = Fixed source LED o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o x o x o x o x o o o o o o o o o o o o o o x o x o x o x o x o o o o o o o o o o o o Any help would be greatly appreciated. Thanks!
well you definatley want to mount everything to one board if possible. organizing it will be about a billion times easier than having an enormous amout of wires everywhere. other than that i wouldnt know where to start, especially with that many LEDS. At least if you want the Bi-Color LEDS to all light the same you can wire in series or parallel depending how you do it (im assuming series would make your life easier)
i have seen a mod with a random led but that many i dont know and the bad thing is i think they all need their own resistor
Hi, There is a mod from Mashie (anemone) with lots of leds in a cluster, maybe you can check out his worklog. link link link greetz, Joungne
this many, each one random (so the're ain't any that are always the same). I would use a PIC16F877A or somthing, and some Shift Registers. This would allow you to control that many LEDs. But 100+ Think of the soldering! u be mad!
i agree. now this may seem like a stupid question to you splashdream, but are all of those necessary? if you make a much smaller grid with far less leds could you get just as nice an effect? i dunno. im just asking
OOPS! Sorry ment to post this in Electronics but somehow was still in Mod Guides when I did. diskreet, never is a question stupid to me. part of life is questioning what we see or hear. that is what makes us human As for are all of these LED's necessary. Yes they are. The mod I am doing will cover the majority of the door on a Chieftec Dragon case. I mapped the layout so so that I just enough spacing between each LED to give it the same effect as an old school Las Vegas light display. If any of you haven't been to Las Vegas or seen pictures of the light displays outside the casinos they used Light Bulbs back in the day to create there colorful displays. Some displays had upwards to half a million bulbs. The end result of the mod is I want it to resemble the super computer "WOPR" from the early 80's movie "War Games". Here is what it looked like here. The LED's will be located behind smoked plexiglas which will have text and numbers like the display to the right of the WOPR computer in the image from the link. The inside of the case will be made to resemble the viewing windo on the left of the computer. As for the soldering, I am fortunate enough to have access to flow solder machine that will make quick work of the soldering of the LED's and controller components. Simply to aid configuration and make it look nice I will be using a rather large PCB. TheAnimus, thanks for the advice. I will try a combination of shift registers and see what I can come up with. I will most likely break this up into 4 smaller quadrants and randomize each quandrant instead of all of the LED's. After thinking about it this makes more sense as the computer in the movie wasn't extremely random and had several lights lit at any one time. I also have to figure out a way to make more than one LED/quadrant light at the same time kind of a 4 channel random effect if that makes sense. Joungne, I saw Anemone but since Mashie used the display as a spectrum analyzer I would still have to butcher his circuitry to make it perform on a random basis. Thanks for all of the suggestions and responses. Time to get back to circuit development
This is of course possible, but will be very complex. My suggestion would to use counters. Cheap counters that can't handle high frequencies. (stuff from radioshack) Why? cause when you feed them a high frequency, or leave their trigger free-floating. Their output tends to look totaly random, jumping all over the place. If the effect needs to be smoothed out, you can use capactiors in parallel with the LEDs. Or find a random number generator circuit, meant to make electronic dice. ---------- But may I suggest another option, depending on how much room you have. An either random option would be to use fiber optic strands. (you can get them in 2mm strands for an LED look) You then have the strands running to a light source. Then you have a moving disk, or belt that is cut out with random holes, that let light through into the fibers. This may be easier or harder depending on if you are electronicly minded, or mechanicly minded. (I personaly would use the counters)
I'd use a PIC. Use a bank of outputs to drive the columns, and a bank to drive the rows. A simple output routine would scan the display out of a buffer into the LEDs. A seperate low speed routine could then randomly flip 1 or more LEDs when desired. A single 16F57 and a couple of dozen output driver transistors would do the job nicely. As this is a 28 pin chip there will be plently of spare pins, so you could hook it up to the HDD indicator light or something and have it change pattern in response. Careful programming should get the LED scan frequency up to a couple of kHz so shouldn't be too objectionable. You could set the resistors up to deliver about 200 mA or so to each LED, as they would have a max duty cycle of about 10%. If the LEDs absolutlely cannot flicker, then a bank of D-latches on each row of LEDs will solve that, but would mean enormously more parts.
Wow! Gotta love the users on Bit. Everyone has a new and equally viable solution for the same problem. Zap is the winner. Using a random number generator is exactly what I was looking for. It just took him mentioning it for it to click. I could use the circuit simililar to the electronic dice to build a random display of the LED's. This would require of course several circuits controlling 1 or so LED's per Zone. Now to identify how I am going to do this. I wish Would be the ultimate retro mod to make a life size WOPR that actually did something instead of being a prop. Instead I will be making it out of my aluminum dragon case. The area on the left of the WOPR unit in the pic above will be in a window behind the Motherboard and will consist of some fun UV lighting and incadensent bulbs to make it appear like the unit in the movie. Thanks to everyone for the help getting me started.
