I’m sorry — it seems to be gone forever, unfortunately. It shouldn’t be too difficult to create a library for the MAX6953. It’s a fairly straightforward part.

Should work, but there are often little simple things that can get in the way. Me, personally? I put a logic analyzer or scope on the thing to see what’s going on before I guess too much. Especially now that you can get an excellent logic analyzer for $200 or less, it’s well worth the investment because you’ll have it and save time and save yourself from frustration. Here’s a review of the Logicport (http://www.nearfuturelaboratory.com/2008/06/21/logicport-overview/) and the Salee Logic (http://www.nearfuturelaboratory.com/2008/10/24/a-new-logic-analyzer-and-an-i2c-compass/). Otherwise, double-check your connections, make sure the data and address lines (SDL and SDA) from the Arduino are going to the correct pins on the MAX6953 and that the address setting pins on the MAX6953 are appropriately configured for the address you are using to point to it — 0x50. Are both chips getting power? Is there a short between the supply and ground? Double check the wiring to the Matrix LEDs. There are lots of wires there, definitely. Plenty of opportunities to mis-wire something..plenty. I’ve put a diagram of my PCB board and schematic in an update to the post, which might help.

The code itself just communicates with the MAX6953 and issues commands to it. You’ll want to familiarize yourself with the specification sheet of that device to look into how to get it to control the second 5×7 LED matrix, which it certainly will do. (I think it will control up to 4, which just requires connecting them properly — lots of wires, etc.)

Thanks for the blog- it has been very helpful. I am working on a project for an education project using a max6953 to power 2 5×7 led matrix. I copied the first parts of your code to test my connections and had no response from the led. I’ve double checked all my wiring, and I am fairly certain it is correct. Does your code work to power 2 led’s? Any thoughts on other things to check?

I saw you did schematics in Eagle, did you track down a .lbr file for the MAX6953? I’m using the MAX6952, but would greatly appreciate a library file for the I2C version if it is no bother?