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8x8x8 LED Cube

Posted: Sun Nov 18, 2012 8:00 pm
by KDLaun
Hello all. I'm an intermediate kit builder making my way through the Jameco LED Cube Kit. First, thanks for posting the great suggestions, photos and schematics on the PyroElectric Project pages. Without them, I'd REALLY be in the dark about some of the aspects of the assembly.

Got a question about the aseembly of the components on the protoboard. (most of my building experience has been with PCB's, perfboard and breadboards) In the project tutorial photos I see a couple 8-pin male headers mounted in the upper left hand of the board on the second row of holes inward. On my circuit board, this falls across a section of the solder pads that is continuous (GND bus strip). I assume you had to somehow modify the board to separate the solder pads in this area?

Karl

http://www.pyroelectro.com/projects/8x8x8_led_cube/

http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?langId=-1&storeId=10001&productId=2168940&catalogId=10001&avad=31303_e35ee04b&source=Avantlink

Re: 8x8x8 LED Cube

Posted: Mon Nov 19, 2012 5:34 am
by ThePyroElectro
KDLaun wrote:Hello all. I'm an intermediate kit builder making my way through the Jameco LED Cube Kit. First, thanks for posting the great suggestions, photos and schematics on the PyroElectric Project pages. Without them, I'd REALLY be in the dark about some of the aspects of the assembly.

Got a question about the aseembly of the components on the protoboard. (most of my building experience has been with PCB's, perfboard and breadboards) In the project tutorial photos I see a couple 8-pin male headers mounted in.............


Hello!

Yes, unfortunately no matter how I laid out the sockets to solder them into the protoboard I couldn't find a way that I was truly happy with, so the way they're laid out as you saw in the photos is how I decided to do it. Unfortunately, that meant that a few pins would be on the bus connection on the edge of the board. To solve this dilemma, I cut the tin/copper with a razor blade and made a few squares that were isolated from the bus (test with a continuity testor on a DMM to be sure they're isolated!!). Then the socket can be connected like all the rest.

I hope this is the only problem you run into while building the project :D .

Good luck!

Re: 8x8x8 LED Cube

Posted: Tue Nov 20, 2012 3:52 am
by KDLaun
Thanks for the info. I found a small razor saw guided by a ruler made a decent slot in the board and made a clear separation between the pads about the same width as the originals.

I noticed on the all-in-one schematic, it lists a 74AC11138 decoder, but in my kit (and the tutorial), it's a 74HC138. Just made the pinouts a bit confusing when I at first pulled up a 11138 datasheet and compared it to the wiring in the build.

Re: 8x8x8 LED Cube

Posted: Tue Nov 20, 2012 4:44 am
by ThePyroElectro
KDLaun wrote:Thanks for the info. I found a small razor saw guided by a ruler made a decent slot in the board and made a clear separation between the pads about the same width as the originals.

I noticed on the all-in-one schematic, it lists a 74AC11138 decoder, but in my kit (and the tutorial), it's a 74HC138. Just made the pinouts a bit confusing when I at first pulled up a 11138 datasheet and compared it to the wiring in the build.


Hello,

Yes, unfortunately the schematic tool I was using didn't have a symbol for the 74HC138 and I didn't have time to fix it up. I have time now, so I'll go fix it up.

Thanks for the note.

**EDIT** updated the schematic.

Re: 8x8x8 LED Cube

Posted: Thu Nov 22, 2012 4:11 pm
by KDLaun
Very nice! Again, thanks for all the work you put into that. Naturally, now I have a few more questions:

1) Cross-referencing your diagram, build tutorial and the included instructions, it looks like pin 15 on the J1 arduino connector has a connection to GND, correct? (not indicated on the schematic)

2) From the project photos, it appears another 0.1u capacitor was attached to Vcc on the 74HC138 chip as was done on the 74HC574's. I assume for the same reason as the others.

3) Can you give me a quick rundown on your technique for chaining the wires on the protoboard? It looks really tight now and 2-3 wires to the same point makes that look even more intense. Would I be better off finding some smaller gauge hookup wire?

Re: 8x8x8 LED Cube

Posted: Thu Nov 22, 2012 4:57 pm
by ThePyroElectro
KDLaun wrote:Very nice! Again, thanks for all the work you put into that. Naturally, now I have a few more questions:

1) Cross-referencing your diagram, build tutorial and the included instructions, it looks like pin 15 on the J1 arduino connector has a connection to GND, correct? (not indicated on the schematic)

2) From the project photos, it appears another 0.1u capacitor was attached to Vcc on the 74HC138 chip as was done on the 74HC574's. I assume for the same reason as the others.

3) Can you give me a quick rundown on your technique for chaining the wires on the protoboard? It looks really tight now and 2-3 wires to the same point makes that look even more intense. Would I be better off finding some smaller gauge hookup wire?


Hey -- no problem, it's a fun kit but the effort is overwhelming.

[1]
Yes, pin 15 should be GND, I changed it on the schematic now. Thank You! This connects the Arduino GND pin to the controller board GND so that everything has the same reference.

[2]
Yes, you're right about the 74HC138 0.1u, it gets one as well. I'll add that to the schematic as well.

[3]
YES! You would definitely be better off using smaller gauge wire (for example Wire-Wrap Wire) and these are all digital signals so wire diameter doesn't really matter. I was just following what I got from Jameco. It's not impossible to do it with the wire they provide. You could consider...instead of connecting all the wires to the same spot like I did at some points, what you can do is solder the pin + 1 or 2 adjacent protoboard pads together so that each wire ends up going to its own 'pad', but they're still connected together through solder (does that make any sense?).

My technique was not super great. I cut 9 wires, bent them, then soldered one end of them to the first IC, then to the second and moved down the bus line, connecting the bus all together IC by IC. The hardest part was connecting the 3rd wire from connector J1 to the bus lines. Take care, do it slowly and you'll get it.

Re: 8x8x8 LED Cube

Posted: Mon Dec 31, 2012 11:08 pm
by KDLaun
Hi Chris,

Thanks again for your helpful suggestions. I finished my cube just before Christmas, and to my amazement, when I first plugged the thing in it actually worked! I took photos as I went along, but I don't see any way to upload them on this forum.

For the benefit of others who may attempt this, here's a few notes from my building experience:

I found 16mm spacing was too wide for the LEDs I had. Some of the cathodes wouldn't touch adjoining parts with that spacing. 15mm was still a bit close, so I ended up using a 14mm grid. (cube is about 4.5") I used MS Publisher to print out a grid template with exact spacing, then temporarily glued it onto a piece of plastic for drilling. I started out using tape to hold the LEDs in alignment for soldering, but later devised a little peg system that I could move into the proceding hole in the assembly jig to align the LED perfectly. I cut a tiny slot in the peg with a razor saw and then added a notched sleeve from a plastic straw that held the cathode in place in the slot.

For the wiring on the back of the protoboard, I picked up the 31AWG wrapping wire you suggested (Radio Shack) and decided that it was just TOO fine to work with. After searching around a bit on the internet, I found some 26AWG sold wire on Amazon and ordered up several spools in different colors. I found I could fit 3 wires into a hole on the protoboard and the wires was still stiff enough to bend them into the shape I wanted. I still ran into problems when trying to blob solder between the D lines where 3 of them connect. I ended up having to use a solder sucker to clear out the mess I had made and then just daisy-chained the wires from the other end of the ICs at the outer edge of the board. I was about ready to smash the whole thing.

I looked for a long time to find a suitable enclosure box that I didn't have to build. I was looking for something in plastic, but ended up with a wooden "photo storage box" from a Michael's craft store. I dumped the cover, cut out a 3/4" plywood base that fit internally and and made the bottom of the photo box the top of my enclosure. Added a couple coats of poly to smooth out the wood, then topped it with flat black paint. Used the same grid template to drill holes for the anodes in the box. (measure twice to be sure it's centered exactly, I was p**ed when I discovered that mine was 1/4" off center AFTER I had it drilled) Doing it again, I'd make a removable TOP instead of a bottom. It was a bear getting the wires soldered on the anodes, so much that I ended up crimping pin sockets onto the wires and then soldering them on the LED leads. Cutting the ribbon cables also turned out to be a challenge. They didn't seem to want to tear, so I ended up cutting strips of 2 wires about 5" back with an x-acto knife. I just left the unused wire attached to support the othere conductor. Even with careful guidance, I had a couple spots where I cut through to the wires and it was a real pain to repair and re-insulate them.

Now that I'm done with construction, I've discovered that I have definitely outbuilt my programming experience. Maybe I should have started with a 2x2x2 :-) I'm still going through the code, trying to figure out how I can program some of my own effects. I started with Arduino last winter and got up to speed pretty quickly on the basics was to the point to where I was writing my own sketches using multiple shift registers. I had to drop the hobby over the summer due to work issues. It's definitely going to be a (re) learning experience. Then again, that's why I took it on. Thanks once more for all the help.

Karl

Re: 8x8x8 LED Cube

Posted: Mon Dec 31, 2012 11:47 pm
by ThePyroElectro
KDLaun wrote:Hi Chris,

Thanks again for your helpful suggestions. I finished my cube just before Christmas, and to my amazement, when I first plugged the thing in it actually worked! I took photos as I went along, but I don't see any way to upload them on this forum.
....
....
....
Then again, that's why I took it on. Thanks once more for all the help.

Karl


Hi Karl,

I'd really, really love to see the finished cube that you have. You can upload photos to a place like http://imgur.com/ and then repost them here. Or just put a video on youtube :D . Hope to see it soon.

Thanks for all the tips...there's really no 1 single best way about the construction process, you just have to sit down figure it out and get it done!

Re: 8x8x8 LED Cube

Posted: Sat Feb 16, 2013 9:47 pm
by Mikam
Hi Chris,

some photo links are dead. Can you fix this?

Re: 8x8x8 LED Cube

Posted: Sun Feb 17, 2013 1:18 am
by ThePyroElectro
Mikam wrote:Hi Chris,

some photo links are dead. Can you fix this?


Hi Mikam,

Thanks for letting me now, however I never meant for those photos to be links.

Did you need to see something specific there?

Re: 8x8x8 LED Cube

Posted: Tue Feb 19, 2013 12:17 pm
by Mikam
Ok, no problem.
I already figured out building the led cube. One thing the I was facing was that the leds were starting to burn out. When one repaired then other two or three was burned out..
I worried that I'll run out spare led's but finally after some changes they are all working,. I did add:

- Grounded wrist
- Insulation of the + wire from battery before the resistor (no contact with out resistor possible)

One other thing that I'd like ask you that can you send the example code for me? As a file?

Thanks for your help

Mikam

Re: 8x8x8 LED Cube

Posted: Sun Feb 24, 2013 7:53 pm
by ThePyroElectro
Mikam wrote:Ok, no problem.
I already figured out building the led cube. One thing the I was facing was that the leds were starting to burn out. When one repaired then other two or three was burned out..
I worried that I'll run out spare led's but finally after some changes they are all working,. I did add:

- Grounded wrist
- Insulation of the + wire from battery before the resistor (no contact with out resistor possible)

One other thing that I'd like ask you that can you send the example code for me? As a file?

Thanks for your help

Mikam


Hi Mikam,

Why not use the project code for download here:

http://www.pyroelectro.com/projects/8x8x8_led_cube/software.html

It includes both the original author's code and my modified pyro version!

Re: 8x8x8 LED Cube

Posted: Tue Aug 06, 2013 9:00 pm
by zcrumpler
Greetings fellow enthusiasts! I'm having some serious issues completing this project and I'm in a bit of a time crunch. Is there anyone out there that'd be willing to dialogue with me about this, possibly through email so I can send pictures of my project as reference? I have the cube assembled, its the control board thats giving me the problems....
Thanks so much!

Re: 8x8x8 LED Cube

Posted: Thu Sep 26, 2013 8:47 pm
by Rjss3
Is there any way you can provide a final picture of the 0.1u dc couplers (decouplers) installed? I'm still a beginner and can't figure out where to solider them. The pictures attached show where in stuck. Thank you very much!

https://www.dropbox.com/s/aoshx4bwxwd5q ... 5%20PM.jpg

https://www.dropbox.com/s/gr3ytpsd48ezb ... 2%20PM.jpg

Re: 8x8x8 LED Cube

Posted: Fri Sep 27, 2013 5:19 pm
by ThePyroElectro
Rjss3 wrote:Is there any way you can provide a final picture of the 0.1u dc couplers (decouplers) installed? I'm still a beginner and can't figure out where to solider them. The pictures attached show where in stuck. Thank you very much!

https://www.dropbox.com/s/aoshx4bwxwd5q ... 5%20PM.jpg

https://www.dropbox.com/s/gr3ytpsd48ezb ... 2%20PM.jpg


Hi,

We'll get some photos for you tonight. Hopefully it clears up how we did it.