The project aims in designing a light illumination system which is capable of identifying the human presence using PIR sensor and detecting the light intensity in room using LDR sensor. The system uses LDR sensor for detecting the light level of room and based on that microcontroller control the intensity of light (AC Bulb). The system makes use of a Microcontroller board. The output from PIR sensor is fed as input to the microcontroller. The output of LDR sensor is fed as input to the microcontroller for day or night detection. The microcontroller will continuously compare output from PIR and LDR. This input is fed to microcontroller which automatically initiates the firing angle control of TRIAC and adjusts the power supplied to the lamp with the help of a solid-state switching mechanism. Zero crossing detector is used for smooth operation of the device. The percentage of light illumination will display on LCD. To achieve this task microcontroller loaded program written in embedded C language.          

The main objectives of the project are:

1. Automatic human presence using PIR sensor.
2. Automatic light intensity detection using LDR sensor.
3. Automatic light illumination control based on PIR and LDR.
4. Zero crossing detector based smooth operation.

         

The major building blocks of this project are:

1. Regulated Power Supply.
2. PIC Microcontroller.
3. Triac with driver.
4. Zero crossing detector.
5. Crystal
6. PIR Sensor.
7. LDR sensor.
8. LCD display.
9. Reset.
10. LED Indicators.

           

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.

             

Block Diagram:      

     

video: