1. A PROJECT REPORT ON
AUTOMATIC ROOM LIGHT CONTROLLER
WITH VISITOR COUNTER
IN THE PARTIAL FULFILMENT OF THE REQUIRMENT FOR THE
DEGREE OF
BACHELOR OF TECHNOLOGY
In
ELECTRONICS AND COMMUNICATION ENGINEERING
By
AKSHAY (07020102003)
Under the guidance of
Ast. Prof. TARUN BHATT
AMRAPALI INSTITUTE OF TECHNOLOGY AND SCIENCES
SHIKSHA NAGAR LAMACHUR, HALDWANI (263139)
U.K Technical University; Dehradun.
April, 2011
[1]

2. TABLE OF CONTENT
· Certificate 3
· Abstract 4
· Declaration 5
· Acknowledgement 6
· Objective 7
· Introduction 8
· Component used- Part A 10
· Component used-Part B 11
· 555 integrated circuit 12
· IC-555 Astable operation 15
· Schematic for constant HV power supply 16
· Condenser Microphone 19
· Capacitor 21
· Piezo buzzer 22
· Relay 23
· Telemetry circuit explanation 25
· Working of telephone cradle switch 26
· Dual tone multiple frequency encoder 30
· Working of system 32
· C program embedded code 37
· Applications 40
· Bibliography 41
[2]

3. CERTIFICATE
This is to certify that Project Report entitled “AUTOMATIC
ROOM LIGHT CONTROLLER WITH BIDIRECTIONAL
VISITOR COUNTER ” that is submitted by AKSHAY in partial
fulfillment of the requirement for the award of the degree B.Tech in
Department of ELECTRONICS AND COMMUNICATION of U.K
technical University, is a record of the candidate own work carried
out by him under my own supervision. The matter embodies in
thesis is original and has not been submitted for the award of any
other degree.
Date: Project Coordinator:
(prof. Y.K SAH)
[3]

4. Project guide:
(ast. Prof TARUN BHATT)
ABSTRACT
The fear of theft and burglary always annoys many people. When lock and keys
become less safe, one can seek the help of electronic security systems.
Such a portable security system is described here.
This electronic setup auto activated whenever the intruder enters to the
unauthorized no entry area. It auto activate the landline number and redial the last
dialed number from the conventional telephone. All we need is to do minor
changes to activate this telephone as it works as to become auto dialer circuit.
Thus whenever the intruder enters to the area, it activates the sensor circuit
of either sound activation or infrared light beam obstruction circuit, the redial
circuit become active and give a ring tone to the receiving end. It may be a
mobile phone or any landline phone or even police control room.
[4]

5. 4
DECLARATION
I hereby declare that this submission is own work and that, to the best of
my knowledge and belief, it contains no material previously published or written
by another person nor material which to a substantial extend has been accepted
for the award of the award of any other degree or diploma of the university or
other institute of the higher leaning except where due acknowledgement has been
made in the text.
Signature:
Name: AKSHAY
Roll No.: 07020102003
Date:
[5]

6. ACKNOWLEDGEMENT
First and foremost, I am deeply indebted to my mentor Ast. Prof. SATYJEET
DAS who inspiration has been unfailingly available to me at all stages of my
training. This has fueled my enthusiasm even further and encouraged me to
boldly step into what was a totally dark and unexplored expanse before me.
I would like to thank Prof. Y.K SAH for his efforts, who was always ready with a
positive comment, whether it was an off-hand comment to encourage me or
constructive piece of criticism.
In course of present work it has been my privilege to receive help and assistance
of my friends. I take great pleasure in acknowledge my debt to them.
I wish to thank my parents for their undivided support and interest who inspired
me and encouraged me to go my own way, without whom I would be unable to
complete my project. At last but not the least I want to thank my friends who
appreciated me for my work and motivated me and finally to God who made all
the things possible.
Signature:
Name: Anubha Upreti
Roll no. 07020102007
[6]

7. Date:
CHAPTER :- 1
Project Overview
[7]

8. 1. Introduction Of Project
1.1 Project Definition:
Project title is “AUTOMATIC ROOM LIGHT
CONTROLLER WITH BIDIRECTIONAL VISITOR COUNTER “.
The objective of this project is to make a controller based
model to count number of persons visiting particular room and
accordingly light up the room. Here we can use sensor and can
know present number of persons.
In today’s world, there is a continuous need for automatic
appliances with the increase in standard of living, there is a sense of
urgency for developing circuits that would ease the complexity of
life.
Also if at all one wants to know the number of people present
in room so as not to have congestion. This circuit proves to be
helpful.
[8]

9. 1.2 Project Overview
This Project “Automatic Room Light Controller with Visitor
Counter using Microcontroller is a reliable circuit that takes over the
task of controlling the room lights as well us counting number of
persons/ visitors in the room very accurately. When somebody enters
into the room then the counter is incremented by one and the light in
the room will be switched ON and when any one leaves the room then
the counter is decremented by one. The light will be only switched
OFF until all the persons in the room go out. The total number of
persons inside the room is also displayed on the seven segment
displays.
The microcontroller does the above job. It receives the signals
from the sensors, and this signal is operated under the control of
software which is stored in ROM. Microcontroller AT89S52
continuously monitor the Infrared Receivers, When any object pass
through the IR Receiver's then the IR Rays falling on the receiver are
obstructed , this obstruction is sensed by the Microcontroller
[9]

10. CHAPTER :- 2
BLOCK DIAGRAM AND ITS
DESCRIPTION
[10]

11. 2.1 Basic Block Diagram
Enter Exit
LCD
Enter Sensor
INTERFACIN
G
Relay Driver A
T
8
9
S
5
2
[11]
Signal
Conditioning
Exit Sensor
Signal Light
Conditioning
Power Supply

12. Fig. 2.1 Basic Block Diagram
[12]

13. 2.2 Block Diagram Description
The basic block diagram of the bidirectional visitor
counter with automatic light controller is shown in the
above figure. Mainly this block diagram consist of the
following essential blocks.
1. Power Supply
2. Entry and Exit sensor circuit
3. AT 89S52 micro-controller
4. Relay driver circuit
1. Power Supply:-
Here we used +12V and +5V dc power supply. The
main function of this block is to provide the required
amount of voltage to essential circuits. +12 voltage is given.
+12V is given to relay driver. To get the +5V dc power
supply we have used here IC 7805, which provides the +5V
dc regulated power supply.
2. Enter and Exit Circuits:-
This is one of the main part of our project. The main
intention of this block is to sense the person. For sensing
the person and light we are using the light dependent
[13]

14. register (LDR). By using this sensor and its related circuit
diagram we can count the persons.
3. 89S52 Microcontroller:-
It is a low-power, high performance CMOS 8-bit
microcontroller with 8KB of Flash Programmable and
Erasable Read Only Memory (PEROM). The device is
manufactured using Atmel’s high-density nonvolatile
memory technology and is compatible with the MCS-51TM
instruction set and pin out. The on-chip Flash allows the
program memory to be reprogrammed in-system or by a
conventional nonvolatile memory programmer. By
combining a versatile 8-bit CPU with Flash on a monolithic
hip, the Atmel AT89S52 is a powerful
Microcontroller, which provides a highly flexible and
cost effective solution so many embedded control
applications.
4. Relay Driver Circuit:-
This block has the potential to drive the various
controlled devices. In this block mainly we are using the
transistor and the relays. One relay driver circuit we are
[14]

15. using to control the light. Output signal from AT89S52 is
given to the base of the transistor, which we are further
energizing the particular relay. Because of this appropriate
device is selected and it do its allotted function.
[15]

16. CHAPTER :- 3
SCHEMATIC DIAGRAM
[16]

17. Transmission Circuit:-
Fig. 3.1 Transmitter circuit
[17]

18. Receiver Circuit:-
Fig. 3.2 Receiver circuit
[18]

19. [19]

20.  CIRCUIT DESCRIPTION:
There are two main parts of the circuits.
1. Transmission Circuits (Infrared LEDs)
2. Receiver Circuit (Sensors)
1. Transmission Circuit:
[20]

21. Fig. 3.3 Transmitter circuit
This circuit diagram shows how a 555 timer IC is
configured to function as a basic monostable multivibrator.
A monostable multivibrator is a timing circuit that changes
state once triggered, but returns to its original state after a
certain time delay. It got its name from the fact that only
one of its output states is stable. It is also known as a 'one-shot'.
In this circuit, a negative pulse applied at pin 2
triggers an internal flip-flop that turns off pin 7's discharge
transistor, allowing C1 to charge up through
R1. At the same time, the flip-flop brings the output
(pin 3) level to 'high'. When capacitor C1 as charged up to
about 2/3 Vcc, the flip-flop is triggered once again, this
time making the pin 3 output 'low' and turning on pin 7's
discharge transistor, which discharges C1 to ground. This
circuit, in effect, produces a pulse at pin 3 whose width t is
just the product of R1 and C1, i.e., t=R1C1.
IR Transmission circuit is used to generate the
modulated 36 kHz IR signal. The IC555 in the transmitter
side is to generate 36 kHz square wave. Adjust the preset in
[21]

22. the transmitter to get a 38 kHz signal at the o/p. around
1.4K we get a 38 kHz signal. Then you point it over the
sensor and its o/p will go low when it senses the IR signal
of 38 kHz.
[22]

23. 2. Receiver Circuit:
Fig. 3.4 Receiver circuit
The IR transmitter will emit modulated 38 kHz IR
signal and at the receiver we use TSOP1738 (Infrared
Sensor). The output goes high when the there is an
[23]

24. interruption and it return back to low after the time period
determined by the capacitor and resistor in the circuit. I.e.
around 1 second. CL100 is to trigger the IC555 which is
configured as monostable multivibrator. Input is given to
the Port 1 of the microcontroller. Port 0 is used for the 7-
Segment display purpose. Port 2 is used for the Relay Turn
On and Turn off Purpose.LTS 542 (Common Anode) is used
for 7-Segment display. And that time Relay will get Voltage
and triggered so light will get voltage and it will turn on.
And when counter will be 00 that time Relay will be turned
off. Reset button will reset the microcontroller.
[24]

25. CHAPTER :- 4
HARDWARE DESIGN & DESCRIPTIONS
Hardware Design:-
[25]

26. Fig. 4.1 Snap of the entire circuit
[26]
Infrared Sensor
TSOP1738
Microcontroller
AT89S52
Relay
7-Segment
Timer IC Display
555

27. 4.1 Procedure Followed While Designing:
In the beginning I designed the circuit in DIPTRACE software.
Dip trace is a circuit designing software. After completion of the
designing circuit I prepared the layout.
Then I programmed the microcontroller using TOPVIEW
SIMULATOR software using hex file.
Then soldering process was done. After completion of the
soldering process I tested the circuit.
Still the desired output was not obtained and so troubleshooting
was done. In the process of troubleshooting I found the circuit aptly
soldered and connected and hence came to conclusion that there was
error in programming section which was later rectified and the
desired results were obtained.
[27]

28. 4.2 List of Components:
Following is the list of components that are necessary to build the
assembly of the Digital Speedometer Cum Odometer:
 Microcontroller – AT89S52
 IC – 7805
 Sensor – TSOP 1738 (Infrared Sensor)
 Transformer – 12-0-12, 500 mA
 Preset – 4.7K
 Disc capacitor – 104,33pF
 Reset button switch
 Rectifier diode – IN4148
 Transistor – BC 547, CL 100
[28]

29.  7-Segment Display
4.3 Description of Components
4.3.1 Microcontroller AT89S52:
The AT89S52 is a low-power, high-performance CMOS 8-
bit microcontroller with 8K bytes of in-system programmable
Flash memory. The device is manufactured using Atmel’s high-density
nonvolatile memory technology and is compatible with
the Industry-standard 80C51 instruction set and pin out. The on-chip
Flash allows the program memory to be reprogrammed in-system
or by a conventional nonvolatile memory pro- grammar.
[29]

30. By combining a versatile 8-bit CPU with in-system
programmable Flash on a monolithic chip, the Atmel AT89S52 is
a powerful microcontroller which provides a highly-flexible and
cost-effective solution to many embedded control applications.
The AT89S52 provides the following standard features: 8K
bytes of Flash, 256 bytes of RAM, 32 I/O lines, Watchdog timer,
two data pointers, three 16-bit timer/counters, a six-vector two-level
interrupt architecture, a full duplex serial port, on-chip
oscillator, and clock circuitry. In addition, the AT89S52 is
designed with static logic for operation down to zero frequency
and supports two software selectable power saving modes. The
Idle Mode stops the CPU while allowing the RAM,
timer/counters, serial port, and interrupt system to continue
functioning. The Power-down mode saves the RAM con- tents
but freezes the oscillator, disabling all other chip functions until
the next interrupt or hardware reset.
[30]

31. FEATURES:-
 8 KB Reprogrammable flash.
 32 Programmable I/O lines.
 16 bit Timer/Counter—3.
 8 Interrupt sources.
 Power range: 4V – 5.5V
 Endurance : 1000 Writes / Erase cycles
 Fully static operation: 0 Hz to 33 MHz
 Three level program memory lock
 Power off flag
 Full duplex UART serial channel
 Low power idle and power down modes
 Interrupt recovery from power down modes
 256 KB internal RAM
 Dual data pointer
[31]

32. 4.3.2 TSOP1738 (INFRARED SENSOR)
Fig. 4.2 Infrared Sensor
Description:
The TSOP17.. – Series are miniaturized receivers for
infrared remote control systems. PIN diode and preamplifier are
[32]

33. assembled on lead frame, the epoxy package is designed as IR
filter. The demodulated output signal can directly be decoded by
a microprocessor. TSOP17.. is the standard IR remote control
receiver series, supporting all major transmission codes.
Features:
· Photo detector and preamplifier in one package
· Internal filter for PCM frequency
· Improved shielding against electrical field disturbance
· TTL and CMOS compatibility
· Output active low
· Low power consumption
· High immunity against ambient light
· Continuous data transmission possible (up to 2400
bps)
· Suitable burst length .10 cycles/burst
Block Diagram:
[33]

34. Fig. 4.3 Block Diagram of TSOP 1738
Application Circuit:
Fig. 4.4 Application circuit
[34]

35. 4.3.3 555 ( TIMER IC):
Fig. 4.5 Timer IC(555)
Description:
The LM555 is a highly stable device for generating accurate
time delays or oscillation. Additional terminals are provided for
triggering or resetting if desired. In the time delay mode of
operation, the time is precisely controlled by one external resistor
and capacitor. For astable operation as an oscillator, the free
running frequency and duty cycle are accurately controlled with
two external resistors and one capacitor. The circuit may be
triggered and reset on falling waveforms, and the output circuit
can source or sink up to 200mA or drive TTL circuits.
Features:
· Direct replacement for SE555/NE555
· Timing from microseconds through hours
[35]

36. · Operates in both astable and monostable modes
· Adjustable duty cycle
· Output can source or sink 200 mA
· Output and supply TTL compatible
· Temperature stability better than 0.005% per °C
· Normally on and normally off output
· Available in 8-pin MSOP package
Applications:
· Precision timing
· Pulse generation
· Sequential timing
· Time delay generation
· Pulse width modulation
· Pulse position modulation
· Linear ramp generator
4.3.4 LTS 542 (7-Segment Display)
Description:
The LTS 542 is a 0.52 inch digit height single digit
seven-segment display. This device utilizes Hi-eff. Red
[36]

37. LED chips, which are made from GaAsP on GaP substrate,
and has a red face and red segment.
Fig. 4.6 7 Segment
Features:
· Common Anode
· 0.52 Inch Digit Height
· Continuous Uniform Segments
· Low power Requirement
· Excellent Characters Appearance
· High Brightness & High Contrast
· Wide Viewing Angle
[37]

38. [38]

39. 4.3.5 LM7805 (Voltage Regulator)
Fig. 4.7 Voltage Regulator
Description:
The KA78XX/KA78XXA series of three-terminal
positive regulator are available in the TO-220/D-PAK
package and with several fixed output voltages,
making them useful in a wide range of applications. Each
type employs internal current limiting, thermal shut down
and safe operating area protection, making it essentially
indestructible. If adequate heat sinking is provided, they can
deliver over 1A output current. Although designed primarily
as fixed voltage regulators, these devices can be used with
external components to obtain adjustable voltages and
currents.
[39]

40. Features:
· Output Current up to 1A
· Output Voltages of 5, 6, 8, 9, 10, 12, 15, 18,
24V
· Thermal Overload Protection
· Short Circuit Protection
· Output Transistor Safe Operating Area
Protection
4.3.6 RELAY CIRCUIT :
Fig. 4.8 Relay
A single pole dabble throw (SPDT) relay is connected
to port RB1 of the microcontroller through a driver
transistor. The relay requires 12 volts at a current of around
[40]

41. 100ma, which cannot provide by the microcontroller. So the
driver transistor is added. The relay is used to operate the
external solenoid forming part of a locking device or for
operating any other electrical devices. Normally the relay
remains off. As soon as pin of the microcontroller goes
high, the relay operates. When the relay operates and
releases. Diode D2 is the standard diode on a mechanical
relay to prevent back EMF from damaging Q3 when the
relay releases. LED L2 indicates relay on.
[41]

42. CHAPTER :- 5
SOFTWARE DESIGN
[42]

43. FLOW CHART:
Fig. 4.7 Flow Chart
If the sensor 1 is interrupted first then the microcontroller
will look for the sensor 2. And if it is interrupted then the
microcontroller will increment the count and switch on the
relay, if it is first time interrupted.
If the sensor 2 is interrupted first then the microcontroller
will look for the sensor 1. And if it is interrupted then the
microcontroller will decrement the count.
When the last person leaves the room then counter goes to 0
and that time the relay will turn off. And light will be turn
off.
[43]

44. Program
;---------------------
;DATED:12/12/2010
;---------------------
;-------------------------------REGISRETS
INFO-------------------------------------------
----------
;
_______________________________________________
_______________________________________________
____
;R0=
;R1= USED
;R2=
;R3= USED
;R4= USED
;R5= USED
;R6= USED
;R7= USED
;---------------------------------PIN-CONFIG.----------------------------------------
--------------
;
_______________________________________________
[44]

45. _______________________________________________
____
;p0=lcd data
;p2.0 lcd control
;p2.1 lcd control
;p2.5 lcd control
;p3.2 ISR
;p3.3 led
;p3.4 led
;p3.6 led
;p3.7 led
;OBJECTIVE: TO PREPARE A AUTO_CONTROLLED ROOM
WITH VISITOR
COUNTER__________________________________
;
_______________________________________________
_______________________________________________
_____
;
$mod51
org 0h
ajmp main
org 003h
acall isr
reti
org 0030h
main:
mov ie,#81h
[45]

46. mov r5,#00
mov r7,#00
acall delay
;----------------------LCD
INITIALIZATION---------------------------------
--------------------------
;
_______________________________________________
_______________________________________________
_____
cjne r7,#00,main2
mov dptr,#mycom
c1: clr a
movc a,@a+dptr
acall comnwrt
jz send_dat
inc dptr
sjmp c1
main2: sjmp main2
send_dat: mov dptr,#mydata
d1:
clr a
movc a,@a+dptr
jz again
acall datawrt
acall delay2
inc dptr
again: sjmp d1
[46]

47. ;----------------------------INTERRUPT SERVICE
ROUTIEN----------------------------------------
------
;
_______________________________________________
_______________________________________________
_____
isr: clr a
inc r7
mov dptr,#mycom1
cmnd: acall comnwrt2
jz chk
inc dptr
sjmp cmnd
acall delay
chk: cjne r5,#00,loop1
mov r6,#30h
ajmp next1
loop1: cjne r5,#01,loop2
mov r6,#31h
acall lights3
ajmp next1
loop2: cjne r5,#02,loop3
mov r6,#32h
acall lights2
ajmp next1
loop3: cjne r5,#03,loop4
mov r6,#33h
acall lights1
ajmp next1
[47]

48. loop4: cjne r5,#04,loop5
mov r6,#34h
acall lights
ajmp next1
loop5: cjne r5,#05,loop6
mov r6,#35h
ajmp next1
loop6: cjne r5,#06,loop
mov r6,#36h
ajmp next1
next1: clr a
mov a,r6
acall incrmnt
acall datawrt2
acall delay3
loop: reti
;---------------------
Subroutiens------------------------------------
----------------------
;
_______________________________________________
___________________________________________
comnwrt: mov p0,a
clr p2.0
clr p2.1
setb p2.5
acall delay
clr p2.5
ret
incrmnt: inc r5
[48]

49. ret
comnwrt2: clr a
movc a,@a+dptr
mov p0,a
clr p2.0
clr p2.1
setb p2.5
acall delay
clr p2.5
ret
lights: clr p2.3
acall delay
lights1: clr p3.4
acall delay
lights2: clr p3.6
acall delay
lights3: clr p3.7
acall delay
ret
datawrt:
mov p0,a
setb p2.0
clr p2.1
setb p2.5
acall delay2
clr p2.5
ret
datawrt2:
mov p0,a
setb p2.0
[49]

50. clr p2.1
setb p2.5
acall delay3
clr p2.5
ret
;--------------------------------------------
DELAYS-----------------------------------------
---
;
_______________________________________________
_______________________________________________
delay:
mov r3,#250
here2:
mov r4,#255
here: djnz r4,here
djnz r3,here2
ret
delay2: mov r1,#05h
back:
mov tmod ,#01h
mov th0,#04ch
mov tl0,#00h
setb tr0
jnb tf0,$
clr tf0
djnz r1,back
ret
delay3: mov r1,#50h
back1:
mov tmod ,#01h
mov th0,#04ch
[50]

51. mov tl0,#00h
setb tr0
jnb tf0,$
clr tf0
djnz r1,back1
ret
org 300h
mycom: db 38h,0eh,01h,06h,80h,0
mycom1: db 38h,0eh,01h,0ch,87h,0
mydata: db 'wlcm 2 amrapali',0
end
CHAPTER :- 6
TESTING AND RESULTS
[51]

52. Testing And Results
We started our project by making power supply. That is easy for
me but when we turn toward the main circuit, there are many problems
and issues related to it, which we faced, like component selection,
which components is better than other and its feature and cost wise a
We started our project by making power supply. That is easy for me but
when I turn toward the main circuit, there are many problems and
issues related to it, which are I faced, like component selection, which
components is better than other and its feature and cost wise also, then
refer the data books and other materials related to its.
I had issues with better or correct result, which I desired. And
also the software problem.
[52]

53. I also had some soldering issues which were resolved using
continuity checks performed on the hardware.
We had issues with better or correct result, which we desired.
And also the software problem.
We also had some soldering issues which were resolved using
continuity checks performed on the hardware.
We started testing the circuit from the power supply. There we
got over first trouble. After getting 9V from the transformer it was not
converted to 5V and the circuit received 9V.
As the solder was shorted IC 7805 got burnt. So we replaced the
IC7805.also the circuit part around the IC7805 were completely
damaged..with the help of the solder we made the necessary paths.
[53]

54. CHAPTER :- 7
FUTURE EXPANSION
[54]

55. FUTURE EXPANSION
· By using this circuit and proper power supply we can
implement various applications
Such as fans, tube lights, etc.
· By modifying this circuit and using two relays we can achieve
a task of opening and closing the door.
[55]

56. CHAPTER :- 8
APPLICATION, ADVANTAGES & DISADVANTAGES
APPLICATION, ADVANTAGES & DISADVANTAGES
[56]

57.  Application
o For counting purposes
o For automatic room light control
 Advantages
o Low cost
o Easy to use
o Implement in single door
 Disadvantages
o It is used only when one single person cuts the rays of
the sensor hence it cannot be used when two person cross
simultaneously.
[57]

58. CHAPTER :- 8
BIBILOGRAPHY
Bibliography
[58]

59.  Reference Books
· Programming in ANSI C: E BALAGURUSAMY
· The 8051microcontroller and embedded systems:
MUHAMMAD ALI MAZIDI
JANICE
GILLISPIE MAZIDI
· The 8051 microcontroller: KENNETH J. AYALA
 Website
· www.datasheets4u.com
· www.8051.com
[59]