Out of filament ALARM

This is a simple way to know you are out of filament, I´m using a momentary switch Cherry and I have uploaded the dimensions in case someone has a similar switch.

The idea is to use an Arduino Attiny85 with a buzzer to make the alarm sound as soon as the filament is getting close to finish

Here you have the video of the filament alarm working:
http://youtu.be/QGUehV8nUc4

If there is anyone who wants the Arduino code for the Attiny85 you can let me know and I´ll be posting it here or