I recently got two Dot Matrix Displays from Freetronics -
They are 32×16 LED panels that can be daisychained via SPI.
It came with a quick library which worked okay but could do with a few enhancements 
My modified library supports multiple displays (tested with 2×1 and 1×2 layout – but should work with other layouts)
It also supports multiple fonts, marquee text, scrolling the display around and grayscale (grayscale sort of works – but not well 
)
I have updated the examples included in the original library to use these new functions.
The library can be downloaded from github.com/cjd/DMD
See freetronics forum for my DMD library
