Lighting effects are always popular and we frequently publish such projects in the pages of Elektor Electronics. Here is a circuit that uses a microcontroller to drive up to 96 bicolour LEDs in a wide range of patterns. A particular feature of the design is the way it exploits the persistence of human vision.Instead of `regular’ LEDs this running light uses so-called bicolour LEDs which can emit two different colours, usually red and green. These are available in versions with three connections (a common cathode and separate anodes) or with two connections. We use the second type in this circuit, where the two LEDs are connected in antiparallel so that one LED or the other lights according to the direction of current flow.