As in the modern world everything is going automatic we have built a system which will automatically sense Power failure, Fire and the entry of an unwanted person in the absence of the owner of house. We have deployed a microcontroller which is used to sense the signals from all the sensors which are placed in the house for sensing different type of failures or security conditions. Apart from this an audio visual alarm is also planted in the house which will get activated at that time.
There are two sets of sensors: one of which sense the entry or exit of a person, when a person enters in the house through the door then a PIR sensor (which act as a sensor for sensing the entry or exit person) will get activated and give a low signal to microcontroller which is sensed by the controller. Then controller in turn the light and also triggers the switch of web cam connected to pc. And when any person exit from home then the light and web cam automatically turned off.
The sensing of entry and exit of persons is done with the help of PIR. This change in output is sensed by the microcontroller and accordingly it activates the audio visual alarm and also captures the person.
PIR:- PIR is an passive infrared sensor.
It always receives the IR rays that are usually emitting from the human body. Whenever any such type of rays will be received by the sensor, it relays the signal to the amplifier .NPN transistor is used as an amplifier. The signal from the amplifier is forwarded to the MCU. This MCU will alert the owner or concerned person either by alarm.