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Topic: Multi-colored LED Cube (Read 1 time) previous topic - next topic

aaroncmears

Hi all!

I recently decided to build an LED cube. I went with 4x4x4, but since I didn't have 64 LEDs of one color, I went ahead and decided to make it four different colors, like so:

R   R  R   R
G  G  G   G
B  B   B   B
W W W W

My question is which resistors should I use? They're each 5mm. Thanks!
-Aaron

CrossRoads

What is the Vf of the different LEDs? You will need a resistor that supports the lowest Vf - probably Red.
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.

aaroncmears


What is the Vf of the different LEDs? You will need a resistor that supports the lowest Vf - probably Red.



I think Red is 2.0. Actually, I was thinking, since the different layers each have their own cathode, could I just put a resistor on each layer for its respective color? So like:

R   R  R  R ---^v^150?v^v---
G  G  G  G ---^v^100?v^v---
B   B  B  B---^v^100?v^v---
W W W W---^v^100?v^v---

(Sorry, though the ^v^v^ would look kinda like a resistor :P)

CrossRoads

One resistor per layer only works if you are turning on one LED at a time.
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.

aaroncmears

#4
Jan 27, 2014, 07:21 am Last Edit: Jan 27, 2014, 07:37 am by aaroncmears Reason: 1
What about in the case of charlieplexing or multiplexing?

CrossRoads

That would be turning on one LED at a time then wouldn't it.
That would also give an agonyzingly slow refresh rate prone to looking flickery.
Much better to drive a whole layer at one time.
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.

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