Hardware components:

• Raspberry Pi Model B
• LPD8806 strip with 44 LED pixels
• Adafruit 16×2 character display with keys
• Behringer UCG 102 Audio Interface
• power supply unit: 5V / 3A DC

The Pi is powered directly from its PINs, because the LED strip needs a lot of current. The LPD8806 can communicate via the SPI interface and the display via the I2C interface. The reason I chose the 16×2 display over a touchscreen was that the model for the touchscreen I found also used the SPI interface. Running two device over one SPI interface might only be able with some crazy hacking, so I decided to go with the LCD.

I chose the Behringer UCG as an input because it is a lot easier than somehow getting the sound input to work with some crazy wiring and amplification circuits. Tried that once with an Arduino and I failed desperately. The UCG is cheap, small and runs on Linux and especially on Raspberry Pi – perfect.