All,

I came across this information on shift registers to increase the number of leds available to be driven by the the MCU pins.

http://www.arduino.cc/en/Tutorial/ShiftOut

Is it possible to apply these shift registers to my LED array kit (while using the same Atmega 168 MCU) and expand it to a bigger array size? Or are these used to control the RGB leds only.

Thanks

Not easily with the array wired the way it is. The best way with the array wired would be to do the SPI array from the tutorial section here.

The reason it won't work with the array wired as is, is because to get a wider matrix, every other column is wired opposite. This doubled the amount of columns without requiring more outputs. They also use the high impedence state to help keep the "off" rows off.