## designing a rubic cube box

jasiyya7520
Posts: 6
Joined: Sat Aug 31, 2019 6:24 pm

### designing a rubic cube box

Hi there, this is my first time doing a project for my son. I'm trying to make an addressable led rubic cube out of a cardboard box. I have bought a 5 meter strip led addressable light for which I will cut into sets of 2 led, as you can see in the picture. The led will be powered by batteries either in sets of two 4 packs which will contain 6v each for a total of 12v with step down to 5v, if not that than I will put 2 battery of 9v each with step down to 5v. What I'm trying to do is a project other people have tried but also take it a step further. I'm new at programming and soldering, so if you guys can help that would be great. and I will posting all the pictures on here, I have not done a whole lot yet, just mess with the designing of the cardboard box, and the led wiring diagram. It will also take me some time to work on this so just be patience with me, and also I am a slow learner.

Thanks again

led1.jpg (164.2 KiB) Viewed 1379 times

hippy
Posts: 5935
Joined: Fri Sep 09, 2011 10:34 pm
Location: UK

### Re: designing a rubic cube box

How does a 3x3 top and bottom with 3x5 sides 'rotate' ?

Or have I misunderstood what you are trying to do ?

One tip for wiring up the LED's - Don't worry about what order they go in the box. Simply place them so they are easy to daisy chain. Then sort out the mapping of where they are and how you want them controlled in software.

jasiyya7520
Posts: 6
Joined: Sat Aug 31, 2019 6:24 pm

### Re: designing a rubic cube box

Thanks hippy for replying. I'm trying to build that out of a cardboard box for my son for holloween. But I am having trouble figuring out the power part. What I mean is that if it will be power by enough battery's and if I need to lower the volts and by how much. Also when I solder all the leds together will the led's be bright enough.

Thanks again

Burngate
Posts: 6002
Joined: Thu Sep 29, 2011 4:34 pm
Contact: Website

### Re: designing a rubic cube box

I've been a Rubik's Cube nut for the last ... is it really 45 years? I really should get out, more.
I find your post most frustrating, and I doubt I'm the only one.

For a start, my cubes don't look quite like your picture - they're quite symmetrical, with 6 3x3 faces (except one with 6 4x4 faces) so I can't find a way to have top & bottom different from front / back / left / right, or put different numbers of LEDs on each.

So please, can you give us more pictures?

As to voltage and brightness, a lot could depend on the particular LEDs you're using, and whether he's going to use it in bright sunlight or under the bed-clothes (my preferred option).

hippy
Posts: 5935
Joined: Fri Sep 09, 2011 10:34 pm
Location: UK

### Re: designing a rubic cube box

Burngate wrote:
Mon Sep 02, 2019 11:30 am
For a start, my cubes don't look quite like your picture - they're quite symmetrical, with 6 3x3 faces (except one with 6 4x4 faces) so I can't find a way to have top & bottom different from front / back / left / right, or put different numbers of LEDs on each.
Serendipitously I did spot a 4x5 Rubik's cube lamp shade yesterday formed around stained glass panels which was intended to be purely decorative rather than function as a virtual Rubik's cube. I guess this could be similarly intended.

I also found some images of Rubik's cubes which are 3x6 by stacking one 3x3 on top of another, and also dividing cubes into half cube slices. So 3x5 could be feasible: 1+1+1 x 0.5+0.5+1+0.5+0.5

jasiyya7520
Posts: 6
Joined: Sat Aug 31, 2019 6:24 pm

### Re: designing a rubic cube box

Thanks Burngate for replying back. Again this project is a small project that I'm trying out for my son. I had measure the cardboard box on him, the box fits him perfectly, and so basically this project will be a beginner project. I know most rubik cube has either a 3x3, 4x4, or a 10x10, but what I was trying to make is a different kind of cube that can be worn on him, like a costume. Also this work is a slow because most of my time is spent working my day job, and as I have said earlier I will post more pictures when I can.

Thanks again

jasiyya7520
Posts: 6
Joined: Sat Aug 31, 2019 6:24 pm

### Re: designing a rubic cube box

Thanks Hippy for the reply to Burngate. Like what you had said

Thanks Again

hippy
Posts: 5935
Joined: Fri Sep 09, 2011 10:34 pm
Location: UK

### Re: designing a rubic cube box

jasiyya7520 wrote:
Mon Sep 02, 2019 3:20 pm
what I was trying to make is a different kind of cube that can be worn on him, like a costume.
That helps clear things up. Thanks.

What make or model of LED strip are you using, and what voltage does it require ?

If you don't know exactly; a link to what you bought will help others identify what you have.

If 12V then the simplest way to power things may be a moderately sized 12V Sealed Lead Acid (SLA) battery, with a 12V-to-5V step-down regulator to the Pi or whatever controls it. But multiple batteries should work just as well.

You might consider a 12V SLA and a separate 5V battery pack for the Pi.

As to how much power will be used - I recall a good rule of thumb is that every single-colour LED which is fully on uses 20mA. So if you have a 3x3 top, four 3x5 sides, with two LED units in each square, that's 138 LED units. With red, green or blue, colours lit on each LED unit that would be something like 3A, so you would need a 12V 3Ah battery for it to last an hour - and it would probably be less.

You would need less power if the LED's were not run at full brightness or not all were lit. And the same battery would correspondingly last longer.

Burngate
Posts: 6002
Joined: Thu Sep 29, 2011 4:34 pm
Contact: Website

### Re: designing a rubic cube box

That explains (I think - I, too, am a slow learner!) the black splodges on your drawing - his kneck and arm holes!
You've got a couple of months, yet, before it needs to be finished, plenty of time - just so long as he doesn't grow out of his box!

My understanding is that 20mA is the maximum current for an ordinary LED, and that most of the time half that can be more than enough.
However, only you (or your son) can say what's bright enough.

250 DotStars or similar, each wanting 10mA per colour, so 7.5A total, is a lot of power, and since he won't want it fading out half way through the evening, I make that about 200WHr for the battery. Unless, of course, you plan on swapping batteries several times throughout the evening.

I'd be trying everything out on the desk before gluing the LEDs to the box, and would be thinking of powering short sections in parallel so that the full current doesn't need to be fed into just one point.

And don't forget pictures.
November 1st, we want pictures, here, of him wearing it.
If there's no pictures it didn't happen!

jasiyya7520
Posts: 6
Joined: Sat Aug 31, 2019 6:24 pm

### Re: designing a rubic cube box

Thanks Burngate for responding. I'm still confuse about the "mA" or the "Whr", like I don't understand the calculations of how many batteries I will need, but I don't need that right now. Right now I am working on cutting the led's and soldering the end with solder. But I will talk more in the morning.

Thanks Again

rileywelsh
Posts: 2
Joined: Wed Sep 04, 2019 3:12 pm

### Re: designing a rubic cube box

That was actually my son's engineering project last fall. We were able to get it done before the deadline using online tutorials.

jasiyya7520
Posts: 6
Joined: Sat Aug 31, 2019 6:24 pm

### Re: designing a rubic cube box

What online tutorials did you use, and how did the project go. Sorry I was trying to rush on my last reply, but I had a big morning, and I needed some sleep, and the same for tonight. I will reply more in the morning about what I have done, and I was thinking I should go with 18 awg wire to wire the led together. What do you think?

Thanks Again