We can implement Temperature sensor based home security system as follows:

Idea:

Use ‘n’ temperator sensors for sensing external obstacles and ‘1’ or ‘2’ temperator sensor/sensors for sensing the atmospheric temperature.

Compare the atmospheric temperature reading with each and every normal obstacle sensors

A huge difference in the temperature variation may have a possiblity that some external obstacles may be there.

Use this inference and drive some alarm.

Requirement:

1) PIC 16F877 IC

2) n+1 or n+2 temperature sensors

3) Alarm

4) MPLAB IDE

5) MPLAB development kit.

Why use PIC 16F877 IC? This IC has the facility to read directly from an analog device. Since the temperature sensors are analog devices it can be interfaced directly to PIC 16F877 IC.

A small embedded program can be needed for comparison operation and that device can drive an external alarm.