I have been working with my new Arduino for the past week. I was looking at the LED Matrix shown on Sparkfun's site. What is the learning curve like to get that working? If there are any tutorials or walkthroughs, I would appreciate it.
Here is the link to the product page:
Thanks!
Not to be facitious, but did you try a google search for something like "sparkfun LED matrix site:arduino.cc" ?
There are heaps of discussions, links and articles. Here is a good starting point http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1203615068/9
Point taken. That is where I will start next time.
Sounds like the MAX7219 is the way to go.
Any suggestions on where to buy those? They don't seem to offer them on Sparkfun or Ladyada, which have been my "go to" spots for Arduino stuff so far.
Thanks.
Doesn't the Sparkfun matrix have a serial interface?
Hi,
I've been working on LedMatrixes with the Max7219. I bought my ICs directly from Maxim site :
I bought the MAX7219CNG+ and I've been using it with the LedControl library (you can find info and tutorials on this site).
Beware, though, that this IC could only control one color of the matrix. So if you have a RG matrix, it would be either R or G or orange. Maybe by using two ICs you could control two colors, but I did not try it so I cannot say if it works or not (or even if it would cause a disaster :o).
The Serial Interface from Sparkfun could control two colors, but I've no experience using it:
Regards,
Sparkfun sells the matrix with or without the "serial backpack". The OP has just the matrix.
As for getting MAX7219 / MAX7221 chips there are 2 ways - as a free sample from MAXIM (easy to find out how on their site) or buy em.
As for buying them, they are not cheep (~USD9.00 each) and your right, none of the uP boutiques carry them. You can order them from big parts suppliers like Digikey, Mouser, Newark, etc. A handy way to search them is
http://octopart.com/search?q=MAX7219
You can also get them from dealers in China . . .
Maxim Integrated ICs which may take about 10 days.
I'd venture to guess the most of the people here that use them get them as free samples. Maxim seems to be very good about their free sample program.
Remember you have other options besides the MAX72xx, some will even let you dim the individual LEDs (PWM). However, and perhaps it's what I'm "use to", I use them all the time to drive RG matrix projects and they work fine. (at least now :
)
No matter what you do, you will be dealing with a lot of wires! (Unless you got the backpack, but that's cheating. 
)
Good luck & Happy Holidays all
FYI LED RGB Matrix's are far cheaper from China. Less than half the price that Sparkfun charge for them :-
I agree the price is good at that vendor, Mike Mc, but their online ordering system really is poorly done. It doesn't give me a comfortable feeling ordering from such a company.
You have to enter billing information even if you're going to use PayPal which already has all that, oh, but you can't just order it directly, you have to sign up. And you can't make your order immediately, you have to wait hours for them to send you an email, so you can click to "activate." And then after you click to "activate," it's not really active yet. More waiting. And each time, it has forgotten what is in my "cart."
Every other vendor just let me (as a new customer) pick parts, say how I want to pay, and I get a receipt by email in a minute or two.
I have 3 similar matrices (one is R only). I had planned on driving them using a 4-16 decoder and a 3-8 decoder, which will cost me 7 pins as expected. I am not sure how well it will work, since I need to do it fast enough for POV to work, but I will let you guys know
FTR, futurlec is an excellent place to buy electronics, with relatively quick delivery even to a backwater country like Australia 
Cheers,
Steve
Halley it is a crap interface I agree. However, I have order items from Ledsee myself and have never had a problem. They are good quality parts for a fraction of the price.
hi BroHogan,
do you have the schematic diagram? or picture on the connection of the 7219+LED matrix (without shield) I have search for no. of page, some people didn't use the resistor and capacitor to connect (http://www.robofun.net/forum/viewthread.php?tid=1360&page=1&extra=page%3D1#pid5740), but some use alot of wiring, (AOL Video - Serving the best video content from AOL and around the web - AOL.com), so don't really know which one can work it out. thanks...
soon,
I put a schematic in a Playground article a while ago . . .
http://www.arduino.cc/playground/Main/MultiplexMAX72xx
Is this what you need?
You will need one current limiting resistor for each chip (Iset) and it's a good idea to put a little cap (.1uf) across the power rails near each chip. Another larger cap (10uf) across the power rails for the circuit is also a good idea. While the caps are not necessary for the functionality, they keep the noise level down.
When you have two 24 pin chips and a 24 pin matrix, there will be a lot of wires! Hope this helps.