The document describes an intelligent energy-saving system designed to control lighting in places like libraries using a combination of PIR sensors, an ATmega8L microcontroller, and LDRs. The system detects human presence and adjusts the lighting accordingly, turning it off when no one is present and on when someone enters the area. It outlines the components, operational principles, and programming logic necessary for the implementation of the system.

1. INTELLIGENT ENERGY SAVER
PREPAIRED BY:-
VYOMESH
UPADHYAY
VIRESH SHUKLA
KRITESH SINGH
JITENDRA KU.
VAISHY
UNDER THE GUIDENCE
OF:-
AMIT SHRIVASTVA
(H.O.D)

2. Intelligent Energy
Saving System
can be used in
places like where
lighting is very
important.
The libraries will
be well
illuminated with
many lamps.
When people are
not present at a
reading place the
lighting can be
made OFF and
when they are
present, the
lighting made
ON.
All these can be
done through by
LDR circuit and
PIR sensor.
ABSTRACT

3. INDEX
Principle of Operation
Electronic devices
PIR Sensor
Microcontroller ATMega8L
LDR
Other ELEMENTS
HOW ITS WORK
CIRCUIT diagram
BLOCK Diagram
PROGRAMME

4. PINCIPLE OF OPERATION
This system mainly depends on PIR sensor, ATMega8l
microcontroller & LDR(light depended resistor).
When the human are enter in room then PIR sensor
sense the radiation emitted by body then sensor will be
“ON” And gives the output 1 to the microcontroller
LDR is used to check the light intensity then if intensity is
enough then it gives output 1 to microcontroller
Microcontroller is used to take logical decision after
giving output by the PIR & LDR

5. DEVICES USED
PIR Sensor
ATMega 8A
LDR
7805,LM324,ULN-2003 Ics
Relays
LEDs and Resistors
Pot

6. PIR(pyro electric infrared sensor)
• PIR sensors allow you to sense motion, almost always used to
detect whether a human has moved in or out of the sensors
range
• PIRs are basically made of a pyro electric sensor which can
detect levels of infrared radiation. The sensor in a motion
detector is actually split in two halves. The reason for that is that
we are looking to detect motion (change) not average IR levels
• When an intruder walks into the detector’s field of vision, the
detector “sees” a sharp increase in infrared energy.

7. ATMega 8A
IT IS 28 PIN IC WHICH IS USED TO TAKE A LOGICAL
DECISION

8. LDR
 LDR’s or Light Dependent Resistors are very useful especially
in light/dark sensor circuits.
 These help in automatically switching ON /OFF the street
lights and etc., normally the resistance of an LDR is very high,
sometimes as very high as 1000000 ohms, but when they are
illuminated with light, resistance drop dramatically.
 Electronic opto sensors are the devices that alter their
electrical characteristics, in the presence of visible or invisible
light.
 The best-known devices of these types are the light
dependent resistor (LDR), the photo diode and the
phototransistors.

9. OTHER ELEMENT
• IC 7805 : IC 7805 is a 5v voltage regulator that restricts the
voltage output to 5v. It is a member of 78xx series of fixed
linear voltage regulator ICs
FUNCTION NAME
PIN
NO
1
2
3
INPUT VOLTAGE(5V-18V)
GROUND(0V)
RAGULATED OUTPUT
VOLTAGE;5V(4.8V-5.2)
INPUT
GND
OUTPUT

10. LM324:- LM324 is a 14pin IC consisting of four independent
operational amplifiers (op-amps). These op-amps are operated by a
single power supply LM324 and need for a dual supply is eliminated.
They can be used as amplifiers, comparators, oscillators, rectifiers

11. ULN2003:-It is 16 pin IC. ULN2003 are high-voltage high-
current Darlington transistor arrays. Each consists of seven npn
Darlington pairs that feature high-voltage outputs. The output
voltage is 50v and current 600mA.

12. RELAY
A relay is an electrically operated switch. Many relays use an
electromagnet to operate switching operation mechanically.
It is 5 terminal device consisting of 1 coil.
When coil is enerzised then a slit is moves from one point to
another point so circuit is completed and load starts works.

13. HOW ITS WORK
Firstly we give the supply at the terminal then it goes to 7805 IC which
converted into 5v.
When any human body moves across the pir sensor then it senses its
radiation and gives the output 1 to the microcontroller.
At the same time LDR senses intensity of light(it can adjust by using of
potentiometer). If intensity is low then it give output 0 to microcontr-
oller. According to input microcontroller gives logical output 1 to the
ULN2003.
ULN2003 gives the output 0 to the relays, which energized the relays
then loads work
If LDR senses enough intensity then it gives 1 to the microcontroller
so it give another output causes on fan will be ON and bulb will be
OFF.

15. POWER SUPPLY

16. PROGRAMME:-
#include <mega8.h>
#include <delay.h>
void pir();
void pir1();
void main(void)
{while (1)
{
int I;
if(PINC.5==1)
{
pir();
}
else
{
pir1();
//PORTB.2=0;
//PORTB.3=0; }}}
void pir()
{if(PINC.4==0)
{PORTB.2=1;PORTB.3=1;delay_ms(15000);}
else
{ PORTB.2=0;PORTB.3=1;delay_ms(15000);} }
void pir1()
{int i;for(i=0;i<=1;i++)
{if(PINC.5==1)
{pir();break;}
else
{delay_ms(100);
}
if(i==1)
{PORTB.1=0;PORTB.2=0;delay_ms(15000); }} }