8x8 Matrix Help

[TheEmperorMing]

I have been banging my head against a small 8x8 Red Matrix (http://adafru.it/455) for a few days now and I finally sat down and tested the display itself. I have read the data sheet linked from the product page as well as looking at the picture of the matrix wired into ground and +5 and I believe I understand that pins 1-4 & 9-12 are cathode while 5-8 & 13-16 are anode.

Matrix Picture.jpg (38.81 KiB) Viewed 174 times

Reading it as such I went ahead and wired all the cathode lines to ground and started poking at the others with a +5 lead protected by a resistor. The results are no where near what I was expecting. When I apply +5 to the anode pins in sequence I do not see columns marching across the matrix.

When I put +5 to pin 16 I get Col 8 lit up like so [10011010], pin 15 col 7 lights up in the same pattern, pin 14 nothing, pin 13 col 1 lights up in the same pattern.

Can someone point me towards what I've done wrong? Have I blown something up through my misunderstanding?

[nathankorth]

I think that with matrices like this one, you connect one cathode at a time to ground while putting voltage to the anodes you want lit in that row only. It's designed for one row to be lit at a time - to light the whole thing, you use a microcontroller to "scan" through the rows fast enough that the scanning is imperceptible.

[TheEmperorMing]

Aaaaannd I was looking at the wrong data sheet. Yellow matrix != red matrix. Case closed