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Brads Electronic Projects Forum • led matrix help please
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led matrix help please

Posted: Sat Aug 14, 2010 12:40 am
by tgraz34
The schematic diagram for the great race led matrix looks different than the schematic diagram for the matrices i bought.

Can someone take a look at the data sheet and tell me if i bought the wrong led matrix? and can someone tell me the difference between the diagrams?

THANKS
anthony

http://www.sure-electronics.net/DC,IC%2 ... -MM103.pdf

Posted: Sat Aug 14, 2010 2:57 am
by bitfogav
Hi Antony,

No that looks like the correct 8x8 Matrix, Have you got the matrix the wrong way round?

check out this picture of a matrix I have on a breadboard, you can see the writing on the side of the matrix, and then you see the coloured wires going to the one side of the matrix,

The wires go to these pins.

Green wire = Green leds
Orange wire = Red leds
Yellow wire = Power supply


Image

Im guessing if the writing on the side of the matrix is the same as yours then you have the right 8x8 matrix..

hope this helps - just ask if you need more help :)

Posted: Sat Aug 14, 2010 3:16 am
by bitfogav
Heres a better picture of the details on the side of the matrix..

Image

Posted: Sat Aug 14, 2010 4:13 am
by tgraz34
Im still confused... looking at brads schematic, it looks like the anode leads are coming out on the left side of the matrix and the cathodes are coming out the top... on my matrix schematic... the cathodes come out the the left and the anodes on top.

Could you tell me what pin on the matrix(data sheet above) should connect to pin one of the 7442?

i think if i know at least one of the connections i can figure the rest out by common sense.

hopefully some of the stuff i just said makes sense :(

Posted: Sat Aug 14, 2010 5:55 am
by bitfogav
The schematics of Brads 8x8 matrix = Anodes are coming out of the TOP and the Cathodes are coming out of the LEFT which connect to the 7442.
On your schematics the Anodes come out of the LEFT and the Cathodes come out of the TOP.

Brads schematics isnt like for like with the datasheet.

Anyway Pin 1 of the 7442 is connected to Pin 24 of the 8x8 matrix.
Pin 2 of the 7442 should then connect to Pin 21 of the 8x8 matrix.

Pin 1 of the 8x8 matrix is the TOP LEFT if you are looking down at the TOP of the matrix ( but note that the writing on the matrix should be on the left hand side as I am showing you in my pictures above)

Hope that makes more sense now :)

Posted: Sat Aug 14, 2010 7:58 am
by tgraz34
hey thanks a lot for the help :)

by the way, i really like your 24x24 led matrix project and i'd love to see a video of it sometime.

Posted: Sat Aug 14, 2010 9:34 am
by bitfogav
No problem :) I always build things using breadboards so then you know if your circuits work before making them :)

And thank you I will upload a video of my 24x24 when its done.

Posted: Sat Aug 14, 2010 9:51 pm
by brad
It looks like I am too late - but ignore the schematic from sure electronics - it's terrible!

Bitfogav is spot on.