The Neopixels Colour Mixer uses a PiDuino board from skpang, to read 3 analog soft pot strips, and to drive a strip of Neopixels.
This project is well explained in Mr SKPang’s blog in link .
The colour mixer uses 3 touch sensitive resistive strips to input Red, Green and Blue colour components. A new Piduino board from skpang reads the 3 analog values, and a python script on the Pi generates colour mix patterns, which are then driven on to the Neopixels. The python also handles timing and mode changes between demo mode, fade mode, and bar mode.
No special setup or configuration is required as this project uses an embedded firmware programmer that automatically programs the Arduino chip on the Piduino board for you. The project demonstrates multi channel analog reading on the Pi, and driving Neopixels, both done from a python script.
 piduino_neopixels-R44 code for the project