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Topic: 8x8x8 multiplexed LED cube with an Arduino Mega 2560 (Read 43760 times) previous topic - next topic

Nick Gammon


The common cathodes need 64 wires, 1 per column, usually soldered to the PCB that makes the base of the cube.
72 wires total.
Vs  8 x 16 wires = 128


Ach, you hardware guys always come up with cool ways of doing things! :)
Please post technical questions on the forum, not by personal message. Thanks!

More info:
http://www.gammon.com.au/electronics

CrossRoads

Yes, indeed - but its always the software that actually makes it look cool when running!
For instance, I have no idea how to write the code that makes it do the vertical paddle wheel kind of rotation, or the bubble rise up thru the middle kind of thing.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

Well then, the theory is clear :)
All that remains to do is to order the components, wait 5 weeks until they arrive from China, solder them together and write the software :) Should be ready by spring :)
Too bad I can't buy the components here in Romania in some local store. Well, I could, but they'd cost 10 times more as sellers and stores are really greedy here.

Anyway, I know I've said this quite a few times already, but I'll say it one more time: thank you very much for taking the time and patience to explain this to me in detail. I've learned a lot from this discussion.
I'll be back with pictures and videos when I'll have something usable or perhaps with a few more questions even before that if things don't go well :)

Thanks!
Andras
Andras
http://iqjar.com

cyclegadget

I have built a 5x5x5 cube which is not powered yet but, getting close.

For the wires that go to the layers, I used bare 24Ga. craft wire that I found in Walmart. The wire has a similar shine as the LED leads so, it is not as obvious that the wires are in the cube. Care has to be taken running the wires but, they work nicely.


Good links: Eagle tutorial= http://www.youtube.com/playlist?list=PLDE1858BD83D19C70
General Arduion tutorials = http://tronixstuff.wordpress.com
http://www.gammon.com.au/forum/bbshowpost.php?bbtopic_id=123

cyclegadget

Let me know if you can see this image. At this point, I have only soldered the cube to the board. No wires have been ran yet in this picture.

Good links: Eagle tutorial= http://www.youtube.com/playlist?list=PLDE1858BD83D19C70
General Arduion tutorials = http://tronixstuff.wordpress.com
http://www.gammon.com.au/forum/bbshowpost.php?bbtopic_id=123

Andras
http://iqjar.com

CrossRoads

Looks nice!

Andras, you can start writing software while you wait.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

cyclegadget


I can see it :) Nice! Aren't those 5mm LEDs?


Yes they are 5mm diffused LEDs. I started with a 3x3x3 cube and made it work basically but, had one bad LED. I then bought 100 more LEDs and made the cube bigger to 5x5x5.

Here is where I got the LEDs. They did take around 3 weeks to arrive using the standard mailing option.
http://stores.ebay.com/LED-Wholesale-World/Blue-LED-/_i.html?_fsub=2777255010&_sid=1016205190&_trksid=p4634.c0.m322
Good links: Eagle tutorial= http://www.youtube.com/playlist?list=PLDE1858BD83D19C70
General Arduion tutorials = http://tronixstuff.wordpress.com
http://www.gammon.com.au/forum/bbshowpost.php?bbtopic_id=123

Funny thing, I was looking at the same seller, only at his 3mm LEDs. I guess he has good prices. I'd like to use 3mm ones because it makes the cube more empty, more transparent, more visible (up to 5x5x5 it probably does not matter but when you get to 8x8x8 it does).
Andras
http://iqjar.com

CrossRoads, I have made a few modifications to your wiring diagram, to make it more understandable for amateurs like myself and to be sure that I have understood things well. I hope you don't mind.



The information I have added:
1. The polarity of the LEDs
2. The value of the resistors
3. The value of the capacitors
4. The type of the MOSFETs and which of their legs goes where
5. The connections between the Arduino and the shift registers

I have removed all the additional circuitry that was around the Arduino or other micro controller on the other pins because I thought that it's not needed. In other words the only pins of the Arduino that need to be connected to anything are D10/SS, D11/MOSI, D13/SCK and GND. I hope I was not wrong...
Andras
http://iqjar.com

Could you please suggest some other MOSFET instead of NDP6020P-ND? These are barely found and expensive on eBay and cannot be found at all in my town's local shops...

Thanks,
Andras
Andras
http://iqjar.com


Andras
http://iqjar.com

dc42


Could you please suggest some other MOSFET instead of NDP6020P-ND? These are barely found and expensive on eBay and cannot be found at all in my town's local shops...


You'll probably not find a suitable P-channel mosfet in your local shops. I suggest you order them from one of the major component distributors. If you are prepared to use a mosfet in an SMD package, then the prices are much better, for example this one http://uk.farnell.com/taiwan-semiconductor/tsm2311cx/mosfet-p-ch-20v-4a-sot23/dp/1864586.
Formal verification of safety-critical software, software development, and electronic design and prototyping. See http://www.eschertech.com. Please do not ask for unpaid help via PM, use the forum.

dc42

PS - the SMD mosfets will also switch faster and can be driven from the cheaper 74HC595 instead of the more expensive TPIC6B595.
Formal verification of safety-critical software, software development, and electronic design and prototyping. See http://www.eschertech.com. Please do not ask for unpaid help via PM, use the forum.

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