Problem / Scenario

Have you ever experienced that...

My roommate rushed into the bathroom for some reason. He came out 1 hour later with a cellphone in hand.
"What did you do?"
>>"Inside a bathroom? Using toilet... Obviously..."
"You sure? Stop playing with your cell phone when you poop!"
>>"Hey! I only used for a while."

Bathroom is a private place though, it's shared among several people at home. Sometimes roommates spend too much time playing cellphone when using bathroom. That's a bad habit for their health as well as for the efficiency of sharing space.

The instant someone brings cellphone going inside a bathroom. Things can happen. However, knocking the door or telling them in person isn't effective enough. So here comes the solution - combination of timer and speaker.

To enhance efficiency of sharing private space like bathroom, I came up with a 15-minute rule powered by a simple circuit created by Particle Photon.