The author 'just wanted to do a bit of microcontroller programming'. However, the project rapidly grew into this impressive and visually attractive pyramid. The circuit consists essentially of a specially-sawn printed circuit board, 23 LEDs and a microcontroller. Despite the fact that the microcontroller is a rather modest Atmel ATtiny2313, the author nevertheless has found room in the 2 KB flash memory for 16 different light sequences. The 23 LEDs are divided into three groups. The lower and middle sections consist of eight LEDs, while the upper section has just seven. The microcontroller has only 20 pins, and so it is not feasible to provide a direct individual drive for each LED. The multiplexing approach adopted uses just eleven output port pins. Buffer transistors are used to increase the current drive capability of each output. The software was written in assembler and can, as usual, be downloaded from the Elektor web pages accompanying this article [1] as eit...