If you buy a P4 32X16 RG Bicolor LED Dot Matrix Unit Board SPI Like from sureelectronics, you'll note that it does not work with any existing arduino code.
In this thread we'll discuss and try to make a working library and all hardware connections.
westfw said in http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1225239439/354
This board uses the same HT3216 driver chip as the other boards that have been under discussion here, so it is no more "true SPI" that those (and no less. When I wrote the first sample code, the main reason for avoiding existing SPI libraries is that the chip commands were of unusual lengths (not a multiple of 8 bits.) (The "sample" code in Sure's documentation only seems to use the HW SPI support for some of the early initialization of the display.)
The 32x16 has FOUR of the HT3216 controllers, with each one driving the LEDs (red and green) in only two of the 8x8 arrays, so the mapping to dots is going to be significantly different. And you have to figure out which one to write to, and how. And deal with the multiple colors somehow. The existing code between the "draw a dot" logic and above the "send a command to an HT1632" is probably pretty useless.