ELECTRONICS - THE KING OF HOBBIES!: Implementing Discrete Fourier Transform in Atmega32 to make an audio spectrum analyzer. Playground - LedControl. LedControl a Arduino library for the MAX7221 and MAX7219 These two chips provide an easy way to control either an array of 64 Led's or up to 8 digits of 7-segment displays.
A detailed description of the hardware and a schematic can be found here. LED series parallel array wizard. Wiimote IR + Seeduino v2.21 + itead bt shield + Quartz composer in Arduino Projects.