The Motion Sensor for Security Light is an automatic lighting system designed to improve security and save electrical energy by switching lights ON only when motion is detected. The system uses a PIR (Passive Infrared) sensor to detect the movement of people or objects within its sensing range. The sensor output is processed by a PIC microcontroller, which activates a relay to turn ON the security light automatically. After a preset time or when no further motion is detected, the microcontroller switches the light OFF, reducing unnecessary power consumption. LED indicators are provided to show the system status. This project is suitable for homes, offices, parking areas, warehouses, and public places, providing reliable security, energy efficiency, and automatic operation with minimal human intervention. To achieve this task microcontroller loaded program written in embedded C language.        

Features of the project:

• Automatic Motion Detection – Uses a PIR sensor to detect human movement and automatically switch ON the security light.
• Automatic Light Control – Turns the light OFF automatically after no motion is detected for a preset time, saving energy.
• Energy Efficient Operation – Reduces unnecessary electricity consumption by operating the light only when required.
• Enhanced Security – Provides instant illumination when movement is detected, improving safety and security.

        The major building blocks of this project are:  

1. Regulated power supply with voltage regulator.
2. PIC Micro controller.
3. Passive Infra Red Sensor (PIR).
4. Relay.
5. Bulb.
6. Crystal oscillator.
7. Reset Button.
8. LED indicator.

        Software’s used:    

1. PIC-C compiler for Embedded C programming.
2. PIC kit 2 programmer for dumping code into Micro controller.
3. Express SCH for Circuit design.

        Regulated power supply:

                     

Block Diagrm:        

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