Presented here is a smart notification system for a door sensor, motion detector, fire alarm and doorbell using Raspberry Pi (RPi) and Pushover app. The project triggers an event through various sensors and sends notifications to your smartphone.

Do you ever leave your key under doormat or other hidden place so another family member can open the door?

or when you arrive at your office and realize your door hasn't been locked.

what if another person open your door using the key that you leave.