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Topic: is arduino uno r3 feasible enough to make a 8x8x8 led cube? (Read 2455 times) previous topic - next topic

yangfizz

I've read some online post on shift registers and find out each shift resigster like 74HC164N controls 8 leds, while 3 pins are used on arduino uno. so if i  build a 8x8x8 led cube, that would require a total of 72 pins to control them. in this case, i can only use up to 4 shift registers because arduino uno have to give 3 pins to each shiftregister. and 4X8 is only 32 ouputs.

yangfizz

I've read some online post on shift registers and find out each shift resigster like 74HC164N controls 8 leds, while 3 pins are used on arduino uno. so if i  build a 8x8x8 led cube, that would require a total of 72 pins to control them. in this case, i can only use up to 4 shift registers because arduino uno have to give 3 pins to each shiftregister. and 4X8 is only 32 ouputs.

Osgeld

first: I would not use the 164, its outputs dont latch and unless your very fast and cute about it what will happen is you will see the bits stream in on your leds in real time causing all kinds of ghosting, something like a 595 is better cause you can stream the bits in to a buffer and once everything is in place flip a switch to show the end result.

second: normal 74xxXX series chips are not that great at handling current,there are better solutions out there

third: you can daisy chain shift registers, most of them have 1 extra output which you feed into the next chip's input making them expandable to large degrees.
http://arduino.cc/forum/index.php?action=unread;boards=2,3,4,5,67,6,7,8,9,10,11,66,12,13,15,14,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,86,87,89,1;ALL

Nick Gammon

@yangfizz - why did you make two posts about 15 seconds apart with the same stuff in them?

Don't do that please.
Please post technical questions on the forum, not by personal message. Thanks!

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

fungus

#4
Oct 15, 2012, 10:51 am Last Edit: Oct 15, 2012, 06:22 pm by fungus Reason: 1

I've read some online post on shift registers and find out each shift resigster like 74HC164N controls 8 leds, while 3 pins are used on arduino uno. so if i  build a 8x8x8 led cube, that would require a total of 72 pins to control them. in this case, i can only use up to 4 shift registers because arduino uno have to give 3 pins to each shiftregister. and 4X8 is only 32 ouputs.


Yes, an Arduino Uno can do it.

There's hundreds of tutorials on the web about how to make LED cubes, try reading a few to get some ideas....

No, I don't answer questions sent in private messages (but I do accept thank-you notes...)

retrolefty

#5
Oct 15, 2012, 03:48 pm Last Edit: Oct 15, 2012, 03:54 pm by retrolefty Reason: 1
I build a 5x5x5 led cube several years ago using a standalone 328p chip. The basic cube was driven using just 8 arduino output pins, 5 to control the 5 LED levels and 3 to control the two series connected 16 bit shift registers/constant current driver chips. So a 8x8x8 cube could be built using 11 output pins and use 8 series connected shift registers. The key is that the shift registers are wired in series so they all together only require 3 arduino output pins, not 3 output pins per shift register.

The hardware was based on a published circuit I found on the web. It shows using a PIC chip but the AVR chip does work just as well but with different software of course. Below is a link to the schematic drawing showing the hardware design. I highly recommend the use of the special shift registers that combine the data shifting along with constant current driver output pins, this saves using 25 (64 for a 8x8x8 cube) series current limiting resistors and makes adjustment of brightness of the leds very simple by just using two 'programming resistors' (one for each shift register).

http://picprojects.org.uk/projects/lc/Cube555Csch.pdf
http://picprojects.org.uk/projects/lc/index.htm


Lefty

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