Greg sent in this great LED project that spells words or makes patterns when it spins “The way this works, is you have an EEprom (electronically eraseable programmable read only memory). This stores data on different lines. You retrieve this data by feeding it binary numbers, (ie. 1=0001, 2=0010, 3=0011, 4=0100, and so on). Each line of code has 8 bits of data, and directly corresponds to how the row of LEDs are lit up. If you put in 10000001, then the top and bottom led would be on. This is kind of tricky to figure out, but you have to make a grid. Since I am using a 4 bit counter, I have a possibility of 16 addresses. So to make a letter, you have to draw up a 16X8 grid, and color in the pixels you want.” Link.
HOW TO – Spinning LED