Need Help Driving a 32x24 LED Matrix Board

I just picked up a cheap 32x24 led matrix board from a surplus store and I would like to control it with the arduino. The board has (8) UCN 5801R and (1) SN74LS164N. I have no idea how to work with these other than some very basic experience with a shift register. After spending over an hour fiddling with my multimeter this thing still makes little sense to me.

Here are the datasheets for the ICs:

The board was clearly meant to be chained to other boards because it has 10 pins on each side (two being ground). It looks like it was cut very roughly from both sides but I am hoping that these were made strategically to allow the board to still function.

Here are some pictures:



Close up of driver circuit:

Close up of driver circuit (reverse side):

Any advice on getting this thing up and running will be appreciated. And if not, at least I will have gotten 768 LEDs for 4 bucks ;)

whoa that's cool but I have a very limited knowledge of using shift resisters too so I can't really help you there.

I so want a darn surplus store near here (or at least within 20 miles). The UK is kinda lacking in them...


Yep, this was a pretty lucky find. Sorry to hear that though, surplus stores are pretty awesome :)

Bump Anyone?

Holy sh*t load of LEDs Batman!

It sounds like it should be simple enough, you just need to identify the data and clock lines for the 164s and the 5800's strobe, then send serial data using those pins.

Why there are 10 signals for daisy chaining the boards is a mystery though, there may be an output enable or something that has to be dealt with as well.

Thanks for the input.
I am not sure how to use the 5800 or any latched driver with the arduino nor do I have a decent understanding of what it is. Are there any tutorials or sites that explain what it it is and how to use it?

At the moment, I assume that it is something like a shift register, letting you greatly reduce the amount of pins needed to control something. Am I on the right track with this one?

I am also still having a hard time figuring out which ICs control the anodes and cathodes of the LEDs.

Pick one LED and trace it back to the chips that control it. You want a representation of the two chips controlling just that LED.

When you have that written out you have a starting point and when you have it you can get more help with that drawing.

To get the polarity of the LED you should be able to put a multimeter on resistance and measure across it. It will light when the polarity is correct. The anode will be the pin the + lead of the meter is touching.

I found something similar. With the correct datasheets and lots of free time, you’ll manage to control it :wink: