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Topic: Direct Wiring 8x8 LED dot Matrix. (Read 9419 times) previous topic - next topic

L4S7

Finally got code to compile and run, with help from this post:


I have been following this helper:


everything is plugged in right, but no lights are flashing.

any help greatly appreciated.


Thanks

L4S7

Here are links couldn't post them because it was my first post oops.


Forum that helped
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1239820770


Link to Arduino helper on LED matrix direct wiring:

http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1239820770

Grumpy_Mike

Those two links were to the same thread. Can you repost the link to your wiring diagram.


Grumpy_Mike

#4
Oct 05, 2010, 08:30 pm Last Edit: Oct 05, 2010, 08:31 pm by Grumpy_Mike Reason: 1
Please do not use that circuit, it is driving LEDs without any current limiting resistors. See:- http://www.thebox.myzen.co.uk/Tutorial/LEDs.html
So you are lucky you haven't lit anything up yet. It looks like you have made an error in wiring things up. Or you have actually put current limiting resistors in and have them in the wrong place or have their value too large.

L4S7

Well i am using these dot matrix's
http://www.virtualvillage.com/10-8-x-8-red-64-led-dot-matrix-displays-3mm-001480-131.html

i have gotten it to work, well i got all of them to light up at once, i cant remember what sketch was running that.

and i also did one
http://arduino.cc/en/Tutorial/RowColumnScanning

with no resistors in place.

would i need to use a resistor for each pin?

Grumpy_Mike

Quote
would i need to use a resistor for each pin?

No you need a resistor somewhere in series with each LED. So if you are driving a row of anodes and a column of cathodes you only need resistors in the column pins.
You also need some sort of current driver for the anodes because the maximum of 40mA doesn't go far in driving 8 LEDs at the same time. Alternatively if you have software that only puts one LED on at a time you don't need the drivers.

ICEM4N

Hi,

I'm not a electronic genius (I do well as programmer), I'm with that same example. I couldn't find on the internet which resistors and how should I connect them. With the LEDs I ordered, I got also some resistors. But since it's in a matrix I don't know where to put them.

For more information, my matrix is "hand-made" a 6x7matrix (maybe I end up with a 7x7, but I don't think I need those extra leds.

Any website which I could learn from? Any help?

Thanks!

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