I spent some time and ported the NeoPixel Matrix library from Adafruit over to the Spark Core. You can even use it in the web IDE if you include the neopixel and Adafruit_GFX libraries in your project.
You can checkout the source code here. I’m pretty confident it should work in any/most projects. I’m a week or two into my project with the Matrix and the library hasn’t failed me once.
It was pretty easy to port actually thanks to the work from @BDub on the NeoPixel library.
I have been waiting to see what I could do with this. Just something to mention. Maybe I just didnt read any release info on this. But anyone proting their existing NeoMatrix code over, delete the GRB and KHz variables in your code to get it working.
Adafruit ships 8x8 matrices as a convenience, which is what I’ve defined in the example. If you are cutting strips and constructing your own matrix, I believe you’d only be using a single matrix defined by the height and width you created.
For example, if you cut a strip into 20 pixel long pieces by 5 rows (100 pixels), your declaration could look like this: