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TLC5940 and RGB led cube guidance


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Hello,
I would like to build an RGB LED cube. I am engineering student and have experience with electronics. I already built a single color 5x5x5 LED cube with shift registers and I would like to make something bigger with RGB LED's.
 
My plan is to build an 8x8x8 RGB LED cube.
I have done some research and it seems that the Texas Instruments TLC5940 might be a good candidate to drive the LED's. Since I'm still a student and have little to no experience designing my own stuff I would like for ask for some guidance. I found a way to arrange the LED's, but Im not too sure that it will work with the TLC5940:

rainbowcon.gif

 

 

My main goal is to drive the LED's with as little pins as possible.
 
My main questions are:
Does driving 8 panels of RGB LED's like the one mentioned seem feasible?
Would you happen to know of a different solution to arrange the LEDs?
Are there other chips that could work as a solution to this?
 
MAXIM Integrated has chips that charlieplex 64 leds with 9 pins(MAX6950), could I use some of these chips as drivers?
 
 
Any comments or help is appreciated.
Thanks
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charlieplexing leads to incredibly dim LED light when many are lit at once, it is more usefull when you have a lot of LEDs and only light 1 or 2 at a time.  because your maximum on time for any LED is 1/n  since you are dividing you tome between them.  2 LEDs can only have 50% max brightnes,  10 LEDs can only have 10% max brightness.  unless you build some external latching circuit, but that adds a lot of complexity

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The TLC5940 is not meant to multiplex lights.

 

MAX7219 (older version of the MAX6950) is the cheapest solution in terms of LED driver chips, but it's 5V power and need 3.5V to drive the IO, so you would need a level shifter or a different microcontroller to use them.  I say cheapest because you can get these real cheap from e-bay.  Even then, you would need 3 for each panel, so 24 of them.

 

8*8 without RGB is a big project.  With RGB it gets a little crazy.

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