08.06.2015: UPDATED
Arduino code source 2.2

• filter for measures and other improvement

LED and sensor cases have been made to insert them through a wood wall thickness 19mm. But they can be mounted on the surface (you just will have to make a hole for the cable on the side).
For Arduino Uno you will find case on my other things.
Main needed parts:

• Arduino Uno
• Uno development shield
• Neopixel ring 16 leds 60mm WS2812
• HC-SR04 ultrasonic module
  I have made the choice to provide power by USB connector, because Neopixel ring need 5V about 1A, so you don't need anything else for the power.
  Code is open source, I'm still working on for improvement.

http://youtu.be/3vy-l2kLTGA
http://youtu.be/43qx3oayNZA