CANduino

On the toilet door in Labitat, we have a LabiDuino (Arduino Clone) to monitor usage 
of the toilet (flash signs etc. when the toilet is occupied).
In v3.5 it has been fitted with a LCD to show some stats on last usage, number of 
usages and average usage time.

Read more and see pretty pictures here: https://labitat.dk/wiki/LabiDuino