Let's Make Robots!

Wiring up my 8 x 8 bicolour display

Hi All. Hope you are all having spiffing Sundays. Sorry, this isnt robotics, but dont find the guys over at arduinoCC especially helpful

I have fallen out of love with my Cyclops robot at the moment (as in, am now trying to think og additional functionallity to add to expand it, but am struggling somewhat) So i turn to my box of bits, and have found this!

http://www.oomlout.co.uk/8-x-8-bicolour-led-matrix-p-233.html

Now i bought this with the idea of playing with Mr Conways Game of life and developing a version with slightly different rules, but annoyingly, this little fellah takes up ALL my Arduino Pins. Not to worry! i decided to solve this by buying a pack of Shift registers!

http://www.oomlout.co.uk/shift-registers-74hc595-x5-p-191.html

but APPARENTLY, if i wire this up to three Shift registers (one for the Anodes, and then one for each colour each for the Cathodes) i am likely to fry the chips.

"Darn!"

This is where the advice comes in.

Should i cut my losses and buy an Adafruit Backpack version, and put what i have in storage (back pack is a ready built shield, with the same display, all chipped up and ready)

Should i cut my losses with the Shift registers, and buy some specific display chips?

Or, the last option, could i solve my issues by putting a transistor on every chip pin to protect it?

I think the transistors might be cool, because if i built Take offs on the Display pins, i could then wire up a bigger, more powerful display (bigger bulbs, rather than more lights) fairly easily? I am a bit of an electronic noob obviously, so a bit of advice, or a nudge in the direction of someoine who has sorted these issues would be greatly appreciated.

Cheers All!

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I think you are confused. What makes you think you would fry your shift registers?

I have read all the datasheets and cannot see your problem.

Thanks Team.

(Re)found this too.

http://www.youtube.com/watch?v=wXvs0CrRPIw

which is pretty much where i am. Will get the transistor array on order, and start wiring up, leaving a hole for the IC.

annoyingly my "usual" supplier has Sink arrays, but not source arrays.

http://www.instructables.com/id/64-pixel-RGB-LED-Display-Another-Arduino-Clone/

I found the instructable by searching google for "how to drive 8x8 matrix rgb arduino"

Would this setup, (this is spanish i think) work? The anodes are being given a pin each, so this may well spread the load?

or would this setup only work on the condition that not all the LEDs were loaded on a given row?

So ive built this. I think it should do the trick.

EXCEPT

in the diagram, the serial OP is connected to the serial OP of the second IC.

surely it should be connected to the Data input?

i have connected it to the DI, rather than the SOP so as i understand it, it should push data firstly through the green IC, and then into the Red. (I suppose that would mean one would start with Data.

now just to get some code going!

need to start with something simple, to test the display....

Am i correct in connecting the OP to the SOP? or have i missed something?

seeing as it cuts out the shift register, the above version should work ok? The 'duino is only having to provide power to one pin at a time (on the rows). I dont intend to use any other pins, and it still leaves me with the Analog pins?