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Topic: 112 RGB LED Coffee Table (Read 18 times) previous topic - next topic


where do you buy a tlc5940, and what is it?


Absolutely great work. I've actually been working on a smaller version of this same idea. How many TLCs are you running? Each chip has 16 channels. And it looks like each LED consumes one channel. So 112/16 is 7 chips? My build is using 25 LEDs. The big difference is that my LEDs are common anode LEDs. So each color has its own channel on the TLC and are connected together across columns. My anodes are connected together down the rows. So I basically set my TLCs, pulse a row for 2ms or so, clear the row, set the TLC for the next row, pulse the next row, etc. The problem I'm running in to is my colors are not consistent at all. If I set my display to white, I get some white, some bluish, some greenish, some redish, some don't turn on much at all, blah blah blah. Any ideas why this might be happening? I guess switching to common cathode LEDs might be an easier fix...


Mar 01, 2010, 05:49 am Last Edit: Mar 01, 2010, 05:54 am by SoCentral2 Reason: 1
I didn't realize I needed one of these until I read this post.  :)

Jeremy --> http://focus.ti.com/lit/ds/symlink/tlc5940.pdf
          |-> http://uk.rs-online.com/web/0422283.html
                & only £2.16!


Ill Mill

The TLC5940's have dot correction which you can set on the individual channels to correct for the varying LED colors. Don't ask me how to do it though, im just starting with these. Also the TLC5940's are in very short supply and most major distributors are on back order. Mouser had some TLC5941NT's (dip package) which are essentially the same chip, however their max Ic is 80mA instead of 120mA and they don't have the EEprom to store the dot correction so you would have to set that in the setup each time.


how did you link processing to the arduino? i guess i could just google that huh? i'll try that too. ;)

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