There is some routine in a bathroom you have to do. These include closing toiled lid, switching lights off. These things especially we menfolk forget time to time. So Nicholas McClanahan built a battery powered Propeller device which makes sure you won’t forget these things.
Toiled buddy does three main things: plays back flushing sounds when toilet seat is up; plays reminder sound to put toilet seat down when light is off and reminds to turn off light when toilet seat is down. All this is achieved with simple circuits. Light is detected with simple photo-resistor. Instead of measuring its voltage with ADC he has chosen to measure RC discharge time. Toilet seat is detected with IR detector circuit where IR diode and IR receiver is used. Infrared signal is modulated at 38kHz to avoid environmental noise. And finally Audio is generated out of stored wav files and played through digital pins. This device can be modified to work for different purposes like open door detector, doorbell, musical instrument and even more.