These LEDs show just one of the capabilities of the Gertboard. I took the sample code and modified it. The first couple patterns are pretty easy to understand. Then after a short pause where no LED is lit up (about ), the next one is a little more complicated. It randomly chooses one of the LEDs and then creates two different "lives" on either side of that LED. Each time through the loop each life can move up or down. So one can move up and the other move down, or they might both move in the same direction. This continues until one of them tries to move to LED 0 or 13 which doesnt exist, and then they die. But the other one continues until it also tries to move to 0 or 13. On the screen it prints out how many times it moved. Best I have seen using the LEDs is over 200. But just running the code on the computer without the delay I have seen over 640 moves without dying.