Controlling an LED Matrix

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So I bought a little 8x8 bi-colour common cathode led matrix (specifically this one https://dlnmh9ip6v2uc.cloudfront.net/datasheets/Components/LED/YSM-1288CR3G2C2.pdf ) and I am fairly sure how to wire it up to multiplex control of the leds but I want to make sure I have everything right.

The Teensy would be wired up to two 74HC595 shift registers which would (in turn) have each rows pattern loaded up into them, one shift register for the red, one shift register for the green.

The outputs from the 595's would be plugged into a pair of ULN2803A ( http://www.farnell.com/datasheets/1690352.pdf ) which would be the current source for the LED arrays. I had been planing on getting 16 individual transitors for this but as I understand it the ULN2803A does what I want?

The common cathodes from each row would be sunk into a TPIC6B595N ( http://www.farnell.com/datasheets/1775182.pdf ) which I would use the Teensy to cycle through 8 pins one at a time to light each row in turn.

First Question: Does that seem like I am doing the right thing?

Second Question: One thing that is confusing me is I see lots of tutorials on the internet about lighting up leds with 74HC595s that don't use any transistors or transitor array like the ULN2803A and just source the current direct from the shift regsiter, this seems really wrong for me as the 595 is only rated up to 70mA max and 8 LEDs all lit up would be pulling over 100mA unless I grossly misunderstand something.

Supplemental Third Question: IT seems the cheapest multi-colour led matrix's are common anode, how do you go about wiring those up?
 
A few years ago, Elco Jacobs published a library called ShiftMatrixPWM, which did something very similar to what you're describing. At least I think it was.

At the time, I build up a circuit board to test it. Here's a quick blog article I wrote... pretty much just a photo.

http://www.dorkbotpdx.org/blog/paul/shiftmatrixpwm_arduino_library_test

Here's the discussion about it, on Arduino's forum.

http://forum.arduino.cc/index.php/topic,66988.135.html

There you can see details on the circuit board I made. It had a LOT of parts, all just resistors, capacitors and transistors, controlled by those cheap HC595 shift registers.

Not sure if this really helps... but if you'd like that PCB, I could put the files as a shared project on OSH Park.
 
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