Password based door lock system using 8051 microcontroller final report

Password Based Door Lock System using
8051 Microcontroller
Traditional lock systems using mechanical lock and key mechanism are being replaced by new
advanced techniques of locking system. These techniques are an integration of mechanical and
electronic devices and highly intelligent. One of the prominent features of these innovative lock
systems is their simplicity and high efficiency. Such an automatic lock system consists of
electronic control assembly which controls the output load through a password. This output load
can be a motor or a lamp or any other mechanical/electrical load. Here we develop an electronic
code lock system using 8051 microcontroller, which provides control to the actuating the load. It
is a simple embedded system with input from the keyboard and the output being actuated
accordingly. This system demonstrates a password based door lock system wherein once the
correct code or password is entered, the door is opened and the concerned person is allowed
access to the secured area. Again if another person arrives it will ask to enter the password. If
the password is wrong then door would remain closed, denying the access to the person.
Principle Behind the Circuit:
The main component in the circuit is 8051 controller. In this project 4×3 keypad is used to enter
the password. The password which is entered is compared with the predefined password. If the
entered password is correct then the system opens the door by rotating door motor and displays
the status of door on LCD. If the password is wrong then door is remain closed and displays
“pwd is wrong” on LCD.
Circuit Diagram of Password Based Door Lock System
using 8051 Microcontroller:

Password Based Door Locking System Project Required
Components:
Hardware Requirements:
 at89c51 controller
 8051 programming board
 Programming cable
 DC battery or 12V,1A adaptor
 4×3 matrix keypad
 16×2 LCD
 5V Relay
 DC motor
 BC 547 Transistor
 10k, 330 Ω resistor (1/4 watt)
 10uF electrolytic capacitor
 33pF capacitors – 2
 12MHz Crystal

 Pot 10k (1/4 watt) – 1
 connecting wires
Software Requirements:
 Keil compiler
 Flash magic
 Proteus
Electronic Code Lock System Circuit Design:
Password based door lock circuit design uses five major components – a Microcontroller, a
Relay, a DC motor, a 4×3 matrix keypad and a LCD. Here AT89C51 microcontroller is used and
it is an 8-bit controller. This controller requires a supply voltage of +5V DC. In order to provide
regulated 5V DC voltage to the controller we need to use 7805 power supply circuit. We can use
9V DC battery or 12V, 1A adaptor as a power source.
Reset Circuit Design: The reset pin of the microcontroller is kept active till the power supply is
in the specified range and a minimum oscillation level is maintained. In other words to ensure
the supply voltage does not falls below the threshold level of 1.2V and the reset pulse width is
greater than 100ms (recommended for 89C51), we select the values of resistor and capacitor
such that RC >=100ms. Here we select a 10K resistor and a 10uF electrolyte capacitor.
Oscillator Circuit Design: A crystal oscillator is used to provide external clock signal to the
microcontroller. To ensure smooth operation, we connect two ceramic capacitors ranges from
20pF to 40pF. This crystal oscillator is connected between pin 18 and 19 of the microcontroller.
Compilation of Microcontroller Code: Once the circuit is designed and drawn on a piece of
paper, the next step is to write and compile the code. Here we select the Kiel uVision software to
write the program in C language.
Prior to writing the code, general steps needs to be followed like creating a new project and
selecting the target device or the required microcontroller. Once the code is written, we saved it
with .c extension and then added it to the source file group under the target folder. The code is
then compiled by pressing F7 key.
Once the code is compiled, a hex file is created. In the next step, we use Proteus software to draw
the circuit. The code is dumped into the microcontroller by right clicking on the IC and then adding
the hex file.

FINAL REPORT
Password Based Door Lock System using
8051 Microcontroller
Submitted by
CHINARAJA BARATAM 13BEC0728
SAMMER 13BEC0475
RAKESH 12BEC0419

ABSTRACT
Security is a prime concernin our day-today life. Everyone wants to be as
much secure as possible. An accesscontrolfor doors forms a vital link in a
security chain. The microcontrollerbasedDoorlocker is an accesscontrol
system that allows only authorized persons to accessa restricted area. The
system is fully controlledby the 8 bit microcontrollerAT89C2051which
has a 2Kbytes of ROM for the program memory. The passwordis storedin
the EPROM so that we can change it at any time. The system has a Keypad
by which the passwordcanbe entered through it. When they entered
passwordequals with the passwordstoredin the memory then the relay
gets on and so that the door is opened. If we entered a wrong passwordfor
more than three times then the Alarm is switchedon. When we go inside
and come back then the microcontrollerwill sense the person using the
Laserlight, the microcontrollerwill automatically open the door for you.
LIST OF TABLES:
1. PIN DESCRIPTION OF AT89C2051
2. PORT ALTERNATE FUNCTIONS
LIST OF FIGURES:
A. BLOCK DIAGRAM
B. PIN OUT OF AT89C2051
C. BLOCK DIAGRAM OF AT89C2051
D. PCB FBRICATION
E. FLOW CHART
F. PINOUT FOR IC LM7805
G. BLOCK DIAGRAM OF IC LM7805
H. PINOUT FOR BC547

1. INTRODUCTION
“Password Based Door Security System using Microcontroller” is used in the
places where we need more security. It can also used to secure lockers and other
protective doors.
The system comprises a number keypad and the keypads are connected to the 8
bit microcontroller AT89C2051. This is one of the popular Microcontrollers. It
has only 20 pins and there are 15 input/output lines. The microcontroller has a
program memory of 2Kilobytes. The microcontroller continuously monitor the
keypad and if somebodyenters the password it will check the entered password
with the password which was stored in the memory and if it they are same then
the microcontroller will switch on the corresponding device.
The systemwill allow the person who knows the passwordand it will not
allow who don‟t know the passwordand the system will also show the
persons who try to break the protection barrier.
2.1 BLOCK DIAGRAM

INTEL’S 8051 Architecture
The generic 8051 architecture sports a Harvard architecture, which contains two
separate buses for both program and data. So, it has two distinctive memory
spaces of 64K X 8 size for both program and data. It is based on an 8 bit central
processing unit with an 8 bit Accumulator and another 8 bit B register as main
processing blocks. Other portions of the architecture include few 8 bit and 16 bit
registers and 8 bit memory locations. Each 8031 device has some amount of
data RAM built in the device for internal processing. This area is used for stack
operations and temporary storage of data. This base architecture is supported
with on chip peripheral functions like I/O ports, timers/counters, versatile serial
9

communication port. So it is clear that this 8051 architecture was designed to
cater many real time embedded needs.
The following list gives the features of the 8051 architecture:
pace.
Timers/Counters
8031 has two 16 bit Timers/Counters capable of working in different modes.
Each consists of a `High' byte and a `Low' byte which can be accessed under
software. There is a mode control register and a controlregister to configure
these timers/counters in number of ways. These timers can be used to measure
time intervals, determine pulse widths or initiate events with one microsecond
resolution up to a maximum of 65 millisecond (correspondingto 65, 536
counts). Use software to get longer delays. Working as counter, they can
accumulate occurrences of external events (from DC to 500 KHz) with 16 bit
precision. In our project we are using 8 bit microcontroller AT89C2051, it is the
advanced 8 bit microcontroller from ATMEL, which incorporates Flash Rom,
and Timer etc.
Features of AT89C2051:
-51 Products
-Level Program Memory Lock
-Bit Internal RAM
-Bit Timer/Counters
12

-Chip Analog Comparator
5. ALGORITM
1. START
2. initialise lcd , keypad
3. clear lcd
4. print “Enter lock code”on lcd
5. get 5 char long password using matrix key pad
6. if input = “12345” then
6.1 print “Enter master code”
6.2 get 10 char long password using matrix key pad
6.3 if input = masterlock then
6.3.1 change user password
6.3.2 go to step 4
6.4 else
6.4.1 print “ wrong code” on lcd
6.4.2 go to step 4
7. else
7.1 if input = userlock or input = default lock then
7.1.1 unlock the lock
7.1.2 retry count = 3
7.1.3 print “ „ #‟ to lock ” on lcd
7.1.4 acceptinput using matrix key pad
7.1.5 if input = “ # ” then lock
7.1.6 goto step 4
7.2 else
7.2.1 decrement retry count
7.2.2 print “ wrong code” on lcd
7.2.3 if retry count = 0 then sound alarm on
7.2.4 go to step 4
8. STOP

PROGRAM
Delay program:
#include "delay.h"
void delayus(unsigned char delay)
{
while(delay--);
}
void delayms(unsigned char delay)
{
while(delay--)
delayus(149);
}
Keypad program:
#include "keypad.h"
#include "delay.h"
bit keystatus = FALSE;
void keypad_init()
{
keyport &=0x0F;
}
unsigned char getkey ()
{
unsigned char i,j,k,key=0,temp;
k=1;
for(i=0;i<4;i++)
{
keyport &=~(0x80>>i);
temp = keyport;
temp &= 0x07;
if(7-temp)
{
if(!col1)
{
key = k+0;
while(!col1);
return key;
}
if(!col2)
{
key = k+1; 24

while(!col2);
return key;
}
if(!col3)
{
key = k+2;
while(!col3);
return key;
}
j++;
}
k+=3;
keyport |= 0x80>>i;
delayms(10);
}
return FALSE;
}
unsigned char translate(unsigned char keyval)
{ if(keyval<10)
return keyval+'
else if(keyval==10)
return 'x';
else if(keyval==11)
return '0';
else if(keyval==12)
return 'e';
}
LCD program:
#include "lcd.h"
#include "delay.h"
#include <REG2051.H>
unsigned char codelockicon[]={0xe, 0xa, 0x1f, 0x1f, 0x1b, 0x1b, 0xe, 0x0};
unsigned char codeunlockicon[]={0xe, 0x2, 0x1f, 0x1f, 0x1b, 0x1b, 0xe, 0x0};
unsigned char codeex[]={0x1f, 0x1b, 0x1b, 0x1b, 0x1b, 0x1f, 0x1b, 0x1f};
unsigned char codeok[]={0x0, 0x1, 0x3, 0x16, 0x1c, 0x8, 0x0, 0x0};
void lcd_reset()
{ lcd_port= 0xFF;
delayms(20);
lcd_port= 0x03+LCD_EN;
lcd_port = 0x03;

delayms(10);
lcd_port= 0x03;
delayms(1);
lcd_port= 0x03;
delayms(1);
lcd_port= 0x02;
delayms(1);
}
void lcd_init ()
{ unsigned char i;
lcd_reset();
lcd_cmd(LCD_SETFUNCTION);// 4-bit mode - 1 line - 5x7 font.
lcd_cmd(LCD_SETVISIBLE+0x04); // Display no cursor - no blink.
lcd_cmd(LCD_SETMODE+0x02); // Automatic Increment - No Display shift.
lcd_cmd(LCD_SETCGADDR);
for(i=0;i<8;i++)
lcd_data(lockicon[i]); 27

for(i=0;i<8;i++)
lcd_data(unlockicon[i]);
for(i=0;i<8;i++)
lcd_data(ex[i]);
for(i=0;i<8;i++)
lcd_data(for(i=0;i<8;i++)
lcd_data(unlockicon[i]);
for(i=0;i<8;i++)
lcd_data(ex[i]);
for(i=0;i<8;i++)
lcd_data(ok[i]);
lcd_cmd(LCD_SETDDADDR); // Address DDRAM with 0 offset 80h.
}
void lcd_cmd (char cmd)
{ lcd_port= ((cmd >> 4) & 0x0F)|LCD_EN;
lcd_port= ((cmd >> 4) & 0x0F);
lcd_port= (cmd & 0x0F)|LCD_EN;
lcd_port= (cmd & 0x0F);
delayus(200);
delayus(200);
}
void lcd_data (unsigned char dat)
{ lcd_port= (((dat >> 4) & 0x0F)|LCD_EN|LCD_RS);
lcd_port= (((dat >> 4) & 0x0F)|LCD_RS);
lcd_port= ((dat & 0x0F)|LCD_EN|LCD_RS); lcd_port= ((dat &
0x0F)|LCD_RS);
delayus(200);
delayus(200);
}
void lcd_str(unsigned char *str)
{ while(*str){
lcd_data(*str++);
}
}
Lock program:
#include "keypad.h"
#include "lcd.h"
#include "delay.h"
#include "lock.h"
unsigned char codemasterlock[10]="1234567890", defaultulock[5]="54321";
unsigned char userlock[5], input[10];
extern bit newlock;
bit check(unsigned char *first, unsigned char *second, unsigned char len)

{
unsigned char i=0; lcd_str("Enter new code");
lcd_cmd(0xC0);
lcd_data(LOCK);
lcd_data(':');
status = getinput(5);
if(status == TRUE){
lcd_cmd(LCD_CLS);
lcd_data(OK);
lcd_str("lockcodesaved!");
newlock = TRUE;
store_code();
delayms(250);
delayms(250);
delayms(250);
delayms(250);
goto exit;
}
else if(status == RETRY)
goto retry1;
else if(status == EXIT
goto exit;
}
else{
lcd_cmd(LCD_CLS);
lcd_str("WRONG CODE!");
delayms(250);
delayms(250);
delayms(250);
delayms(250);
goto exit;
}
}
else if(status == RETRY)
goto retry;
else if(status == EXIT)
goto exit;
exit:;
}
char getinput(unsigned char max)
{ unsigned char i,key; i=0;

while(1){
while(!(key=getkey()));
key = translate(key);
input[i]=key;
if(key=='x'){
if(i==0)
return EXIT;
i--;
lcd_cmd(0xC2+i);
lcd_data(' ');
lcd_cmd(0xC2+i);
}
else if(key=='e')
{ return TRUE;
}
else{
i++;
if(i>max){
lcd_cmd(LCD_CLS); lcd_data(EX);
lcd_str(" Codetoo Long...");
delayms(250);
delayms(250);
delayms(250);
delayms(250);
return RETRY;
}
lcd_data('*');
} } }
void store_code(){
unsigned char i;
for(i=0;i<5;i++)
userlock[i]=input[i];
}
Main program:
#include "lcd.h"
#include "keypad.h"
#include "lock.h"
#include "delay.h"extern unsigned char input[10], userlock[5];
extern unsigned char codedefaultulock[5],masterlock[10];
bit newlock=FALSE;
unsigned char retrycount=3;
void main(){
unsigned char status,i=0;

bit lockstatus;
lcd_init();
keypad_init();
while(1){
lcd_cmd(LCD_CLS);
lcd_str("Enter lock code");
lcd_cmd(0xC0);
lcd_data(LOCK);
lcd_data(':');
status = getinput(5);
if(check(input,"12345",5)){
setulock();if(check(input,masterlock,10)){
retrycount=3;
lcd_cmd(LCD_CLS);
lcd_data(EX);
lcd_str("UNBLOCKED");
lcd_data(EX);
delayms(250);
delayms(250);
delayms(250);
delayms(250);
}
else{
lcd_cmd(LCD_CLS);
lcd_data(EX);
lcd_str("WRONG CODE");
lcd_data(EX);
delayms(250);
delayms(250);
delayms(250);
delayms(goto blocked;
}
}
}
}
done:;
}
}

Resistor:
Resistor is a component that resists the flow of direct or alternating electric
circuit. Resistors can limit or divide the current, reduce the voltage, protect an
electric circuit, or provide large amounts of heat or light. An electric current is
the movement of charged particles called electrons from one region to another.
Resistors are usually placed in electric circuits. Physicists explain the flow of
current through a material, such as a resistor, by comparing it to water flowing
through a pipe. Resistors are designed to have a specific value of resistance.
Resistors used in electric circuits are cylindrical. They are often colour coded by
three or four colour bands that indicate the specific value of resistance.
Resistors obey ohm‟s law, which states that the current density is directly
proportional to the electric field when the temperature is constant.
7.2 Capacitor:
Capacitor or electric condenseris a device for storing an electric charge. The
simplest form of capacitor consists of two metal plates separated by a non
touching layer called the dielectric. When one plate is charged with electricity
from a direct current or electrostatic source, the other plate have induced in it a
charge of the oppositesign; that is, positive if the original charge is negative
and negative if the original charge ispositive. The electrical size of the capacitor
is its capacitance. Capacitors are limited in the amount of electric charge they
can absorb;they can conductdirect current for only instances but function well
as conductors in alternating current circuits. Fixed capacity and variable
capacity capacitors are used in conjunction with coils as resonant circuits in
radios and other electronic equipment. Capacitors are produced in a wide
variety of forms. Air, Mica, Ceramics, Paper, Oil, and Vacuums are used as
dielectrics depending on the purposefor which the device is intended.
7.3 Transistor:
Transistor is a device which transforms current flow from low resistance path to
high resistance path. It is capable of performing many functions of the vacuum
tube in electronic circuits, the transistor is the solid state device consisting of a
tiny piece of semi conducting material, usually germanium or silicon, to which
three or more electrical connections are made.
N-type and P-type Transistor:
A germanium or silicon crystal, containing donorimpurity atoms is called a
negative or n-type semiconductorto indicate the presence of excess negatively
charged electrons. The use of an acceptorimpurity produces a positive, or p-
type semiconductorso called because of the presence of positively charged
holes. When an electrical voltage is applied, the n-p junction acts as a rectifier,
permitting current to flow in only onedirection. If the p-type region is connected
to the positive terminal of the battery and the n-type to the negative terminal, a
large current flows through the material across the junction.

7.4 Diode:
Diode is a electronic device that allows the passageof current in only one
direction. The first such devices were vacuum-tube diodes, consisting of an
evacuated glass or steel envelope containing two electrodes – a cathode and an
anode. The diodes commonly used in electronic circuits are semiconductor
diodes. There are different diodes used in electronic circuits such as Junction
diode, Zener diode, Photo diodes, and tunnel diode.
Junction diodes consist of junction of two different kinds of semiconductor
material. The Zener diode is a special junction type diode, using silicon, in
which the voltage across the junction is independent of the current through the
junction.
7.5 Integrated circuits
RegulatorIC (LM 7805):
The LM7805 monolithic 3-terminal positive voltage regulators employ
internal current-limiting, thermal shutdown and safe-area compensation,
making them essentiallyindestructible. If adequate heat sinking is
provided, they can deliver over 1.0A outputcurrent. They are intended as
fixed voltage regulators in a wide range of applications including local(on-
card) regulation for elimination of noise and distribution problems
associatedwith single-point regulation. In addition to use as fixed voltage
regulators, these devices canbe used with external components to obtain
adjustable output voltages and currents. Considerable effort was expended
to make the entire series of regulators easyto use and minimize the number
of external components. It is not necessaryto bypass the output, although
this does improve transient response. Input bypassing is needed only if the
regulatoris locatedfar from the filter capacitorof the powersupply.
thermal -
Output transistorsafe area protection

RelayDriver (BC547):
The BC547 transistor is an NPN Epitaxial Silicon Transistor. The BC547
transistor is a general-purpose transistor in small plastic packages. It is used in
general-purpose switching and amplification BC847/BC547 series 45 V, 100
mA NPN general-purpose transistors.
The BC547 transistor is an NPN bipolar transistor, in which the letters "N" and
"P" refer to the majority charge carriers inside the different regions of the
transistor. Most bipolar transistors used today are NPN, because electron
mobility is higher than whole mobility in semiconductors, allowing greater
currents and faster operation. NPN transistors consistof a layer of P-
dopedsemiconductor(the "base")between two N-doped layers. A small current
entering the base in common-emitter mode is amplified in the collector output.
In other terms, an NPN transistor is "on" when its base is pulled high relative to
the emitter. The arrow in the NPN transistor symbolis on the emitter leg and
points in the direction of the conventional current flow when the device is in
forward active mode. One mnemonic device for identifying the symbol for the
NPN transistor is "not pointing in." An NPN transistor can be considered as two
diodes with a shared anode region. In typical operation, the emitter base
junction is forward biased and the base collector junction is reverse biased. In
an NPN transistor, for example, when a positive oltage is applied to the base
emitter junction, the equilibrium between thermally generated carriers and the
repelling electric field of the depletion region becomes unbalanced, allowing
thermally excited electrons to inject into the base region. These electrons
wander (or "diffuse") through the base from the region of high concentration
near the emitter towards the region of low concentration near the collector. The
electrons in the base are called minority carriers because the base is doped p-
type which would make holes the majority carrier in the base
*PCB FABRICATION
The first step of assembling is to produce a printed circuit board. The
fabrication of the programcounter plays a crucial role in the electronic field.
The success of the circuit is also dependent on the PCB. As far as the costis
concerned, more than 25% of the total costis for the PCB design and
fabrication.
The board is designed using a personalcomputer. The layout is drawn using
the software“AdobePageMaker 6.5”. The layoutis printed in a “buffer sheet”
using a laser procedure. First, a negative screen of the layout is prepared with
the help of a professionalscreen printer. Then the copper clad sheet is kept
under this screen. The screen printing ink is poured on the screen and brushed

through the top of the screen. The printed board is kept under shadefor few
hours till the ink becomes dry.
The etching medium is prepared with the un-hydrous ferric chloridewater. The
printed board is kept in this solution till the exposed copper dissolves in the
solution fully. After that the board is taken out and rinsed in flowing water
under a tap. The ink is removed with solder in order to prevent oxidation.
Another screen, whichcontains component side layout, is preparedandthe
same is printedonthe component side of the board. A paper epoxy laminate
is usedas the board. Boththe component and the track layout of the
peripheral PCB is givenat the end of this report.
APPLICATIONS
Our electronic doorlock performed as expected. We were able to
implement all the functions specifiedin our proposal. The biggesthurdle
we had to overcome with this projectwas interfacing the micro controller
with the hardware components. We feel that this electronic doorlock is
very marketable because it is easyto use, comparatively inexpensive due to
low powerconsumption, and highly reliable. This door lock is therefore
particularly useful in applications such as hotel room door locks,
residential housing, and even office buildings.
10. FUTURE ENHANCEMENTS
separate passwords.
e system can be easily connected to the personal computer for further
control.
Other than the speaker sounds, all the lights are made to turned on if password
entered is wrong for three times and also a hidden camera is used to record the
faces who trespassed.
We can use this system as an attendance register for the students to enter a class
room with their respective password.
11. CONCLUSION
This project is meant for security systems whose access is only for respected
authorities. Using a microcontroller the password entered is checked with the
stored password and then does the corresponding operations. Here we use a 5
digit password for better secrecy.

12. REFERENCES
Electronic circuits and devices: J.B. Gupta.
Op-amps and linear integrated circuits: Ramakanth A. Gayakward
Integrated circuits : K.R. Botkar
The 8051 microcontrollers: Muhammed Ali Mazidi

Password based door lock system using 8051 microcontroller final report

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