We have seen many LED cube projects that can generate lots of great effects. Sometimes the problem is that in too large cubes inner layers are hardly visible. So what if to build a LED based rectangle with less layers of LEDs. Dooievriend have found great combination of 3D effect and visibility.
He has built 16x16x5 rectangle configuration of blue LEDs that displays spectrum of music being played. The heart of this spectrum analyzer is PIC32 microcontroller running at 80MHz. It has enough power to sample sound and calculate DFT of the signal. It samples input signal at 14kHz and then calculates spectrum frequencies from range 20 – 7000Hz. It refreshes the spectrum graph at 80 FPS so it looks really live.