Comments: Arduino showing multiplexed LED matrix

Hi, I just recreated your setup going from the pictures you posted, but there is one thing I don't understand (note that I'm very new to electronics.)

On the last column, the lines (orange wires) that connect the negative sides of the LEDs, simply go nowhere?
What does this accomplish? Does this have something to do with putting +5V on the negative sides of the LEDs, to run that power away without damaging the LEDs? But wouldn't it be better then to connect all those last wires to a ground? Or would that require another consumer of some sort then?

Any enlightenment would be very much appreciated :)

Posted by Bernard Kerckenaere at February 6, 2009 15:17

Hi Bernard,

Well spotted, and congrats on recreating the board! The orange wires on the right (see the board) are only there in case you wanted to connect another board and extend the circuit out to the right. I'd toyed with doing that to make a 5x5 array but didn't get around to it.

So in summary: yes, you could leave those five far-right orange wires out as they're not connected to anything.

Have fun!

Posted by Paul Makepeace at February 6, 2009 17:16

Hi Paul,

I also managed to rebuild your setup with 4x4 white LEDs. It's all working so far, the only trouble is that some LEDs seem to glow a little bit even though they should be turned off in the pattern. They are not as bright as those that are rightly turned on. Do you have any idea what might cause this? I can send you a pic of my setup if you like, it's looking little different due to the limitations of by mread board ;-)

Anyway, it's great that you put this information on the web, it really helped me to get my matrix working somehow :-)

Thanks in advance for any hints.


Posted by sMiLe at March 6, 2009 14:43

Hey just a heads up, I wanted to let everyone know that Xio Dibin speaks English. I hope I posted in the right location?

Posted by Shaun Davis at April 23, 2009 01:59

What kind of power source are you using?

Posted by Patrick at August 12, 2010 11:31

Thank you for the tutorial AND the pictures.
As a beginner, I could easily recreate your circuit.
Most of people are using shift registers in their tutorial, even for 4*4 grids, this is way easier ;))

Posted by pim at February 21, 2011 18:01

Great code. It was a little trick at first, but I've got it now. Your code example made it a lot easier for me to figure out. If anybody else stops by and has trouble check out my code based on the code presented here at:

Posted by Michael Baker at March 18, 2011 00:36
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