@Steve: I used an off-cut piece of 0.1" Veroboard, spread the tips of the leads into the exposed slots of the serrated edge, and then slid the LED housing toward the Veroboard, thereby forcing the leads further apart.
I didn;t really understand what you were saying here until I watched your video, at which point I thought "Brilliant!" I'm really looking forward to reading your future blogs on this topic showing the techniques you used for straigntening the wire and the jigs you build to help in the assembly of this cube.
@Max: I didn;t really understand what you were saying here until I watched your video, at which point I thought "Brilliant!" I'm really looking forward to reading your future blogs on this topic showing the techniques you used for straigntening the wire and the jigs you build to help in the assembly of this cube.
I have to agree; I could have stated this a little more clearly. For example, "I used the serrated edge from an offcut piece of Vero board as a comb to spread the led leads out."
@Steve: I could have stated this a little more clearly. For example, "I used the serrated edge from an offcut piece of Vero board as a comb to spread the led leads out."
I don't think there was a problem with the way you stated it -- it's just when you said "Veroboard" I immediately thought of sticking the LED leads thru the holes ... and my mind went off on the wrong track. As soon as aI saw the video I realized what you meant and I also realized it was a really ingenious solution to the problem.
@Steve: As you know, your work on this has inspired me to build my own 8x8x8 cube (how could I live with a 4x4x4 cube knowing that you were cackling over an 8x8x8 beauty?)
Now, you are using regular RGB LEDs, which will involve lots of multiplexing and stuff. I've decided to go with the Adafruit NeoPixel versions of these devices. Each of these LEDs contains its own controller with current limiting resistors and three 8-bit PWM drivers (one per RGB channel).
I've already taken delivery of the LEDs -- I'm eagerly awaiting your future construction blogs to get ideas for the building of my own cube...
Just what I didn't need -- yet another project LOL
@Max: Now, you are using regular RGB LEDs, which will involve lots of multiplexing and stuff. I've decided to go with the Adafruit NeoPixel versions of these devices. Each of these LEDs contains its own controller with current limiting resistors and three 8-bit PWM drivers (one per RGB channel).
I have taken delivery of 10 of those Adaruit NeoPixels myself but haven't gotten round to trying them out yet. A cube built with these little beauties would make the programming a little easier with no multiplexing required and no software PWM to write. The downside would be the increased current consumption due to the non multiplexing. The current for a NeoPixel cube if all led's are white could be between 20-30 amps as apposed to just under 4 amps for my cube which will be using multiplexing.
You and I still need to discuss whether or not one of the PCB's I had manufactured for my cube (another blog coming soon) would be suitable for a NeoPixel version.
@Steve: You and I still need to discuss whether or not one of the PCB's I had manufactured for my cube (another blog coming soon) would be suitable for a NeoPixel version.
I'm up to my armpits in alligators fighting fires without a paddle at the moment (i never metaphor I didn't like) -- I'll be working from a hotel in Louisiana next week (I'm going down there with my wife and son to celebrate her birthday because that's where her family lives) -- so let's chat after that when we've posted your next two blogs on the construction of your cube and i have a better idea as to what will be required for mine...
Having just gone through the construction of a 8x8x8 RGB LED cube for a senior design lab with a group, I thought I could provide a few tips, mainly on the contruction side of things. The construction of the cube is by far the most time consuming part of the whole thing (It took the four of us working together approx. 80 hours. 2000+ solder joints takes a lot more time than you think). I found that using a drill to straighten out the wire worked the best. If you clamp one end of the wire in a vice and the other in the drill, you can run the drill for about 10-15 seconds while pulling back slighty, and the wire becomes super straight. I was able to do an 108 inch piece of wire at a time, which yielded 6 18inch pieces. The dimensions of my cube are probably bigger than what yours will be because I went with 10mm LEDS as opposed to the 5mm ones that you have, so the spacing is different. I used the HNTE jig method, which worked out very well.
If you are interested in our project, you can see our final design video here. In the video I mispoke and switched the cathode and anode definition, FYI, but the rest of it should be accurate. Let me know if you have any questions, as I'd be happy to answer them.
Thanks for all your comments and tips which are very much appreciated. Your cube is absolutely awesome and I must admit I have already taken inspiration from your constructional web site and video. I actually have a link to you web site from one of my hallway lighting project blogs (end of page 2).
You might be surprised to know that I have already posted some YouTube video's of my progress, one of which is dedicated to wire straightening. I have an accompanying blog which will be posted here on EE Times in the next few days followed shortly after by my blog on the 8x8 panel construction.
Currently I have 5 panels built and the 6th well under way. I have a base PCB to mount the cube on to that I designed then had made professionally.
I have also constructed a test circuit that uses multiplexing to drive the 8x8 panels as a proof of concept. It seems to work quite well and I have successfully test the 5 panels. As yet I haven't sorted the code for PWM though. I will be looking closely at you implementation of PWM which I think uses Bit Angle Modulation.
Once I have the other 3 panels made I will blog the testing and final assembly, before going onto blogging the creation of my control circuitry.
It would be great to keep in touch with a fellow cube builder :-)
You could drive your whole LED cube in 24 bit colour, with a 30Hz refresh rate, using one pin of a FPGA. Each LED buffers the signal, tidies it up and hands it off to the next LED.
All you need is a 5V @ 30A as each LED is 0.3W,
What can I say, if only the Neo-Pixels were available before I started this project. I am where I am and it's to late to change. I already have experience with the Neo-Pixel strips as well so quite used to coding them. Maybe the next cube.
Max has bought enough Neo-Pixels and intends on building an 8x8x8 cube with them. Lets see how he gets on. I was looking to see if I could adapt my PCB design for him to use.
@kevinwongs: Very cool idea. With so many solder points. how to you plan to solder those. With any of these soldering irons it will take a lot of time...
By my calculation and when the cube finally rests on its PCB there will have been 2384 solder joints made. I use a fairly cheap solder station like this one.
I'm building the cube in 8 flat 8x8 panels. The blog for the construction of these panels will be posted in the next few days, here is a link to the video in the meantime. The 8 panels will then be assembled into the cube. It has taken me a couple of months doing a bit as and when time allows to get this far.
"Progress isn't made by early risers. It's made by lazy men trying to find easier ways to do something."― Robert A. Heinlein
I have to admit that your Eager Beaver ways of building these NxNxN cubes appeals to the engineer nerd in me - BUT - I try to remember the RAH quote above and think it through before I start building. If I had Protean Pete to help I might launch into the same project. Unfortunately my wife has other more pressing projects to while away my hours.
I will leave you with this thought. Prove , solve for n>2.
Meanwhile I'll ponder my elegant solution and publish it before I retire. If there had been more room in this post I could have scribbled it down here ;-)
NASA's Orion Flight Software Production Systems Manager Darrel G. Raines joins Planet Analog Editor Steve Taranovich and Embedded.com Editor Max Maxfield to talk about embedded flight software used in Orion Spacecraft, part of NASA's Mars mission. Live radio show and live chat. Get your questions ready.
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