The document is a project report on an electronic voting machine (EVM) designed using the AT89S52 microcontroller. It covers the introduction to EVM technology, references to hardware and software components, and details on circuit diagrams and working mechanisms. Additionally, it discusses the power supply requirements, advantages and disadvantages, and potential future applications of the voting system.

1. [1]
(Raghogarh, Guna)
Project Report
Electronic Voting Machine (EVM)
(10B11CI401)
Submitted By: Submitted To:
Saurav Kumar (121127) Dinesh Kumar Verma Sir
Rohan Agrawal(121115)
Ravikant (121112)
Rajat Pokharna (121108)
Rahul Tyagi (121107)
A-4 (ECE)
JAYPEE UNIVERSITY OF ENGINEERING & TECHNOLOGY

2. [2]
ACKNOWLEDGEMENT
We wish to express our sinceregratitude to our Microprocessors &
microcontrollers sir Mr. D.K. Verma for his timely encouragement, proper
guidance and humorous illuminating discussions.
We also owe our gratitude and thankfulness to all our friends, who havebeen a
perennial sourceof guidance and inspiration.
We once again wish to express our sincere gratitude to all those who helped us
to complete this report.
In the words of W.Wilson --
“ I not only usedall the brain I had, but all that I could borrow. ”

3. [3]
CONTENTS
S.NO. Details Page No.
1. Introduction 4
2. Pin description of 8952 6
3. Block Diagram of EVM 10
a. Working of EVM using 89C52
b. Circuit Diagram of 89C52
c. Hardware Description
4. Explanation of circuit diagram of EVM 13
5. Software Coding of EVM 15
6. Advantages & Disadvantages 29
7. Application & Future Scope 29-30
8. Bibliography 31

4. [4]
INTRODUCTION
This project is design to make understand the technology used in a now a day’s voting machine
system, which is used in whole world. These voting machines are equipped with the CPU, which
control the voting machine. The voting machine is programmed for the specific operation.
Every operation on the voting machine is defined is display on the Computer Monitor.
In this project we try to give the Idea of prototype voting machines. We are using micro
controller AT89S52(of 8051 series) for controlling the voting operation. There is a Monitor
display for showing the status of voting by interfacing the voting machine with the PC. For
connecting the voting machine with PC we use the Hyper Terminal communication system,
which are already come with the Window2000XP operating system.
8952 IC MICROCONTROLLER
Features:-
• Compatible with MCS-51® Products
• 8K Bytes of In-System Programmable (ISP) Flash Memory
– Endurance: 1000 Write/Erase Cycles
• 4.0V to 5.5V Operating Range
• Fully Static Operation: 0 Hz to 33 MHz
• Three-level Program Memory Lock
• 256 x 8-bit Internal RAM
• 32 Programmable I/O Lines
• Three 16-bit Timer/Counters
• Eight Interrupt Sources
• Full Duplex UART Serial Channel
• Low-power Idle and Power-down Modes
• Interrupt Recovery from Power-down Mode
• Watchdog Timer
• Dual Data Pointer
• Power-off Flag
Description:-
The 89S52 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

5. [5]
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-systemor by a conventional nonvolatile memory programmer.
Block diagram (89C52) :

6. [6]
Pin Description:-
VCC
Supply voltage.
GND
Ground.
Port 0
Port 0 is an 8-bit open drain bi-directional I/O port. As an output port, each pin can sink eight
TTL inputs. When 1s are written to port 0 pins, the pins can be used as high impedance inputs.
Port 0 can also be configured to be the multiplexed loworder address/data bus during accesses
to external program and data memory. In this mode, P0 has internal pullups. Port 0 also
receives the code bytes during Flash programming and outputs the code bytes during program
verification. External pullups are required during program verification.
Port 1

7. [7]
Port 1 is an 8-bit bi-directional I/O port with internal pullups. The Port 1 output buffers can
sink/source four TTL inputs. When 1s are written to Port 1 pins, they are pulled high by the
internal pullups and can be used as inputs.
Port 2
Port 2 is an 8-bit bi-directional I/O port with internal pullups.The Port 2 output buffers can
sink/source four TTL inputs.When 1s are written to Port 2 pins, they are pulled high by the
internal pullups and can be used as inputs. As inputs, Port 2 pins that are externally being
pulled low will source current (IIL) because of the internal pullups.
Port 3
Port 3 is an 8-bit bi-directional I/O port with internal pullups.The Port 3 output buffers can
sink/source four TTL inputs.When 1s are written to Port 3 pins, they are pulled high bythe
internal pullups and can be used as inputs. As inputs,Port 3 pins that are externally being pulled
low will sourcecurrent (IIL) because of the pullups.
RST
Reset input.
ALE/PROG
Address Latch Enable (ALE) is an output pulse for latchingthe low byte of the address during
accesses to externalmemory. This pin is also the program pulse input (PROG)during Flash
programming.
PSEN
Program Store Enable (PSEN) is the read strobe to external program memory.
EA/VPP
External Access Enable. EA must be strapped to GND in order to enable the device to fetch code
from external program memory locations starting at 0000H up to FFFFH.
XTAL1
Input to the inverting oscillator amplifier and input to the internal clock operating circuit.
XTAL2
Output from the inverting oscillator amplifier.
Special Function Registers

8. [8]
Timer 2 Registers:
Control and status bits are contained in registers T2CON () and T2MOD () for Timer 2. The
register pair (RCAP2H, RCAP2L) are the Capture/Reload registers for Timer 2 in 16 bit capture
mode or 16-bit auto-reload mode.
Interrupt Registers:
The individual interrupt enable bits are in the IE register. Two priorities can be set for each of
the six interrupt sources in the IP register.
Dual Data Pointer Registers:
To facilitate accessing both internal and external data memory, two banks of 16-bit Data
Pointer Registers are provided: DP0 at SFR address locations 82H-83H and DP1 at 84H-85H.
Power Off Flag:
The Power Off Flag (POF) is located at bit 4 (PCON.4) in the PCON SFR. POF is set to “1” during
power up. It can be set and rest under software control and is not affected by reset.
Memory Organization

9. [9]
MCS-51 devices have a separate address space for Program and Data Memory. Up to 64K bytes
each of external Program and Data Memory can be addressed.
Program Memory
If the EA pin is connected to GND, all program fetches are directed to external memory. On the
AT89S52, if EA is connected to VCC.
Data Memory
The AT89S52 implements 256 bytes of on-chip RAM. The upper 128 bytes occupy a parallel
address space to the Special Function Registers.
Watchdog Timer
(One-time Enabled with Reset-out)
The WDT is intended as a recovery method in situations where the CPU may be subjected to
software upsets. The WDT consists of a 13-bit counter and the Watchdog Timer Reset
(WDTRST) SFR. The WDT is defaulted to disable from exiting reset. To enable the WDT, a user
must write 01EH and 0E1H in sequence to the WDTRST register (SFR location 0A6H).
UART
The UART in the AT89S52 operates the same way as the UART in the AT89C51 and AT89C52.
Capture Mode
In the capture mode, two options are selected by bit EXEN2 in T2CON. If EXEN2 = 0, Timer 2 is a
16-bit timer or counter which upon overflow sets bit TF2 in T2CON.This bit can then be used to
generate an interrupt. If EXEN2 = 1, Timer 2 performs the same operation, but a 1- to-0
transition at external input T2EX also causes the current value in TH2 and TL2 to be captured
into RCAP2H and RCAP2L, respectively.
Auto-reload (Up or Down Counter)
Timer 2 can be programmed to count up or down when configured in its 16-bit auto-reload
mode. This feature invoked by the DCEN (Down Counter Enable) bit located in the SFR T2MOD
Baud Rate Generator
Timer 2 is selected as the baud rate generator by setting TCLK and/or RCLK in T2CON (Table 2).
Note that the baud rates for transmit and receive can be different if Timer 2 is used for the
receiver or transmitter and Timer 1 is used for the other function. Setting RCLK and/or TCLK
puts Timer 2 into its baud rate generator mode
Programmable Clock Out
A 50% duty cycle clock can be programmed to come out onP1.0, as shown in Figure 9. This pin,
besides being a regularI/O pin, has two alternate functions. It can be programmed to input the

10. [10]
external clock for Timer/Counter 2 or to output a 50% duty cycle clock ranging from 61 Hz to 4
MHz at a 16 MHz operating frequency.
Interrupts
The AT89S52 has a total of six interrupt vectors: two external interrupts (INT0 and INT1), three
timer interrupts (Timers 0, 1, and 2), and the serial port interrupt.
Oscillator Characteristics
XTAL1 and XTAL2 are the input and output, respectively, of an inverting amplifier that can be
configured for use as an on-chip oscillator
Idle Mode
In idle mode, the CPU puts itself to sleep while all the on chip peripherals remain active. The
mode is invoked by software. The content of the on-chip RAM and all the special functions
registers remain unchanged during this mode. The idle mode can be terminated by any enabled
interrupt or by a hardware reset.
Power-down Mode
In the Power-down mode, the oscillator is stopped, and the instruction that invokes Power-
down is the last instruction executed. The on-chip RAM and Special Function Registers retain
their values until the Power-down mode is terminated.
Block Diagram of EVM :

11. [11]
Working of EVM using 89C52
The Project Electronic Voting System is an interesting project which uses 89S52 microcontroller
as its brain. The project is designed for four contestants. Voters can poll their vote to any one of
the contestant.
The 89S52 microcontroller contains four ports of each eight pins. In this project one port is
dedicated for micro switches for four contestants, master switch for polling officer. 4 LEDs are
connected to indicate the switch bounce conditions. A simple yet powerful program is written
in assembly language and burned into the microcontroller to accept votes and to count total
votes polled.
Polling officer switch (master) is provided to avoid multiple polling of single voter. Every voter
should get approval from the polling officer. If the polling officer issues approval with his
control switch, then only a voter can poll his vote. This issuance of approval is indicated by an
long buzzer beep.
Vote count are stored in PC and display the total number of votes polled and individual
contestant-vise votes polled.
A buzzer is provided for audio effect of switch bounce. Whenever a switch is bounced, the
system acknowledges the bounce by a short beep sound. This buzzer is driven by an NPN
transistor. If voter tried to multiple polling long beep sound.
This project uses regulated 5V, 500mA power supply. 7805 three terminal voltage regulator is
used for voltage regulation. Bridge type full wave rectifier is used to rectify the ac output of
secondary of 230/12V step down transformer.
Circuit Diagram:

12. [12]
Hardware description :-
Power supply:-
Power supply is a reference to a source of electrical power. A device or system
that supplies electrical or other types of energy to an output load or group of loads is called a
power supply unit or PSU. The term is most commonly applied to electrical energy supplies, less
often to mechanical ones, and rarely to others. Here in our application we need a 5v DC power
supply for all electronics involved in the project. This requires step down transformer, rectifier,
voltage regulator, and filter circuit for generation of 5v DC power.
Circuit diagram:-

13. [13]
Transformer:-
Transformer is a device that transfers electrical energy from one circuit to
another through inductively coupled conductors the transformer's coils or "windings". Except
for air-core transformers, the conductors are commonly wound around a single iron-rich core,
or around separate but magnetically coupled cores. A varying current in the first or primary
winding creates a varying magnetic field in the core or cores of the transformer. This varying
magnetic field induces a varying electromotive force EMF or voltage in the secondary winding.
This effect is called mutual induction. If a load is connected to the secondary circuit, electric
charge will flow in the secondary winding of the transformer and transfer energy from the
primary circuit to the load connected in the secondary circuit.
The primary winding is connected to a60-hertz ac voltage source. The magnetic field builds
up and collapses about the primary winding .the expanding and contracting magnetic field around the
primary winding cuts the secondary winding and induces an alternating voltage into the winding. This
voltage causes alternating current to flow through the load. The voltage may be stepped up or down
depending on the design of the primary and secondary windings.
BRIDGERECTIFIER:-
A bridge rectifier makes use of four diodes in a bridge arrangement to achieve full-wave
rectification. This is a widely used configuration, both with individual diodes wired as shown
and with single component bridges where the diode bridge is wired internally.
The full-wave bridge serves to convert an AC input into a DC output, the addition of a capacitor
may be desired because the bridge alone supplies an output of fixed polarity but continuously
varying.
The function of this capacitor, known as a reservoir capacitor is to lessen the variation in the
rectified AC output voltage waveform from the bridge. One explanation of 'smoothing' is that
the capacitor provides a low impedance path to the AC component of the output, reducing the

14. [14]
AC voltage across,and AC current through, the resistive load. In less technical terms, any drop in
the output voltage and current of the bridge tends to be cancelled by loss of charge in the
capacitor. This charge flows out as additional current through the load. Thus the change of load
current and voltage is reduced relative to what would occur without the capacitor. Increases of
voltage correspondingly store excess charge in the capacitor, thus moderating the change in
output voltage / current.
REGULATOR IC (7805):-
It is a three pin IC used as a voltage regulator. It converts unregulated DC current into regulated
DC current. Normally we get fixed output by connecting the voltage regulator at the output of
the filtered DC. It can also be used in circuits to get a low DC voltage from a high DC voltage (we
use 7805 to get 5V from 12V).
DIODE:-
The diode is a p-n junction device. Diode is the component used to control the flow of the
current in any one direction. The diode widely works in forward bias. Diode when the current
flows from the P to N direction. Then it is in forward bias. The Zener diode is used in reverse
bias function from N to P direction
Explanation of circuit diagram of EVM
1. Initially when the switch is closed, allows the evm to take the vote.The vote is taken only
when push button is pressed and the led D1 is switched ON.

15. [15]
2. A push button is assigned to each party. When the push button of the desired party is
pressed, the led is switched off which indicates that the vote is cast and the buzzer gives a
beep.
3. Again the push button is pressed so that the evm is ready to take the next vote
which is indicated through the led D1.The same process is repeated until all the voters cast
their votes.
4. To view the results of each respective party, the switch must be opened.
5.To know the result of the party, the push button of the respective party must be pressed so
that the number of votes cast for the party is displayed on the lcd screen.

16. [16]
SOFTWARE CODE
C code:
// Program to make a voting machine using LCD
#include<reg51.h>
#define msec50
#define lcd_data_str_pinP2
sbitrs = P1^0; //Registerselect(RS) pin
sbitrw = P1^1; //Readwrite(RW) pin
sbiten= P1^2; //Enable(EN) pin
sbitini_pin= P3^0; //Start votingpin
sbitstop_pin= P3^5; // Stopvotingpin
sbitcandidate_1=P3^1; //Candidate1

17. [17]
sbitcandidate_2=P3^2; //Candidate2
sbitcandidate_3=P3^3; //Candidate3
sbitcandidate_4=P3^4; //Candidate4
intmax = 0;
intcarry = 0;
intarr[4];
intvote_amt[3],j;
unsignedintvote_1,vote_2,vote_3,vote_4;
voiddelay(intdelay_time) //Time delayfunction
{
intj,k;
for(j=0;j<=delay_time;j++)
for(k=0;k<=1000;k++);
}
voidlcd_cmd(unsignedcharcmd_addr) //FunctiontosendcommandtoLCD
{
lcd_data_str_pin= cmd_addr;
en= 1;
rs = 0;
rw = 0;
delay(1);
en= 0;
return;
}
voidlcd_data_str(charstr[50]) //Functiontosendstring
{

18. [18]
intp;
for (p=0;str[p]!='0';p++)
{
lcd_data_str_pin= str[p];
rw = 0;
rs = 1;
en= 1;
delay(1);
en= 0;
}
return;
}
voidlcd_data_int(unsignedintvote) //Functiontosend0-9character values
{
char dig_ctrl_var;
intp;
for (j=2;j>=0;j--)
{
vote_amt[j]=vote%10;
vote=vote/10;
}
for (p=0;p<=2;p++)
{
dig_ctrl_var= vote_amt[p]+48;
lcd_data_str_pin= dig_ctrl_var;
rw = 0;
rs = 1;
en= 1;

19. [19]
delay(1);
en= 0;
}
return;
}
voidvote_count() //Functiontocountvotes
{
while (candidate_1==1&& candidate_2==1 && candidate_3==1 && candidate_4==1);
if (candidate_1==0)
{
while (candidate_1== 0);
{
vote_1 = vote_1+ 1;
}
}
if (candidate_2==0)
{
while (candidate_2== 0);
{
vote_2 = vote_2+ 1;
}
}
if (candidate_3==0)
{
while (candidate_3== 0);
{
vote_3 = vote_3+ 1;

20. [20]
}
}
if (candidate_4==0)
{
while (candidate_4== 0);
{
vote_4 = vote_4+ 1;
}
}
}
voidlcd_ini()
{
lcd_cmd(0x38);
delay(msec);
lcd_cmd(0x0E);
delay(msec);
lcd_cmd(0x01);
delay(msec);
lcd_cmd(0x81);
delay(msec);
lcd_data_str("Welcome!!!");
delay(100);
lcd_cmd(0x01);
delay(msec);
lcd_cmd(0x80);
delay(msec);
lcd_data_str( "Press");
delay(msec);

21. [21]
lcd_cmd(0x14);
delay(msec);
lcd_data_str("button");
delay(msec);
delay(msec);
lcd_cmd(0xC0);
delay(msec);
lcd_data_str("to");
delay(msec);
lcd_cmd(0x14);
delay(msec);
lcd_data_str("vote");
delay(100);
lcd_cmd(0x01);
delay(msec);
lcd_cmd(0x80);
delay(msec);
lcd_data_str("P1");
delay(msec);
lcd_cmd(0x84);
delay(msec);
lcd_data_str("P2");
delay(msec);
lcd_cmd(0x88);
delay(msec);
lcd_data_str("P3");
delay(msec);
lcd_cmd(0x8C);
delay(msec);

22. [22]
lcd_data_str("P4");
delay(msec);
vote_count();
lcd_cmd(0x01);
delay(msec);
lcd_cmd(0x85);
delay(msec);
lcd_data_str("Thank");
delay(msec);
lcd_cmd(0x14);
delay(msec);
lcd_data_str("You!!");
delay(10);
return;
}
voidresults() //Functiontoshowresults
{
inti;
carry = 0;
lcd_cmd(0x01);
delay(msec);
lcd_cmd(0x80);
delay(msec);
lcd_data_str("Results");
delay(msec);
lcd_cmd(0x14);
delay(msec);
lcd_data_str("Are");

23. [23]
delay(msec);
lcd_cmd(0x14);
delay(msec);
lcd_data_str("Out");
delay(msec);
lcd_cmd(0x01);
delay(msec);
lcd_cmd(0x80);
delay(msec);
lcd_data_str("P1");
delay(msec);
lcd_cmd(0x84);
delay(msec);
lcd_data_str("P2");
delay(msec);
lcd_cmd(0x88);
delay(msec);
lcd_data_str("P3");
delay(msec);
lcd_cmd(0x8C);
delay(msec);
lcd_data_str("P4");
delay(msec);
lcd_cmd(0xC0);
delay(100);
lcd_data_int(vote_1);
delay(msec);

24. [24]
lcd_cmd(0xC4);
delay(msec);
lcd_data_int(vote_2);
delay(msec);
lcd_cmd(0xC8);
delay(msec);
lcd_data_int(vote_3);
delay(msec);
lcd_cmd(0xCC);
delay(msec);
lcd_data_int(vote_4);
delay(300);
arr[0] = vote_1;
arr[1] = vote_2;
arr[2] = vote_3;
arr[3] = vote_4;
for( i=0; i<4; i++)
{
if(arr[i]>=max)
max = arr[i];
}
if ( (vote_1== max) && ( vote_2 != max) && (vote_3!= max)&&(vote_4!= max) )
{
carry = 1;
lcd_cmd(0x01);

25. [25]
delay(msec);
lcd_cmd(0x82);
delay(msec);
lcd_data_str("Hurray!!!");
delay(50);
lcd_cmd(0xC4);
delay(msec);
lcd_data_str("P1");
delay(msec);
lcd_cmd(0x14);
delay(msec);
lcd_data_str("wins");
delay(msec);
}
if ( (vote_2== max) && ( vote_1 != max) && (vote_3!= max)&& (vote_4!= max) )
{
carry = 1;
lcd_cmd(0x01);
delay(msec);
lcd_cmd(0x82);
delay(msec);
lcd_data_str("Hurray!!!");
delay(50);
lcd_cmd(0xC4);
delay(msec);
lcd_data_str("P2");
delay(msec);
lcd_cmd(0x14);
delay(msec);

26. [26]
lcd_data_str("wins");
delay(msec);
}
if ( (vote_3== max) && ( vote_2 != max) && (vote_1!= max)&&(vote_4!= max) )
{
carry = 1;
lcd_cmd(0x01);
delay(msec);
lcd_cmd(0x82);
delay(msec);
lcd_data_str("Hurray!!!");
delay(50);
lcd_cmd(0xC4);
delay(msec);
lcd_data_str("P3");
delay(msec);
lcd_cmd(0x14);
delay(msec);
lcd_data_str("wins");
delay(msec);
}
if ( (vote_4== max) && ( vote_2 != max) && (vote_3!= max)&&(vote_1!= max) )
{
carry = 1;
lcd_cmd(0x01);
delay(msec);
lcd_cmd(0x82);
delay(msec);

27. [27]
lcd_data_str("Hurray!!!");
delay(50);
lcd_cmd(0xC4);
delay(msec);
lcd_data_str("P4");
delay(msec);
lcd_cmd(0x14);
delay(msec);
lcd_data_str("wins");
delay(msec);
}
if (carry==0)
{
lcd_cmd(0x01);
delay(msec);
lcd_cmd(0x82);
delay(msec);
lcd_data_str("clash");
delay(50);
lcd_cmd(0x14);
delay(msec);
lcd_data_str("between!!!");
delay(50);
if(vote_2== max)
{
lcd_cmd(0xC5);
lcd_data_str("P2");
delay(50);
}

28. [28]
if(vote_3== max)
{
lcd_cmd(0xC9);
lcd_data_str("P3");
delay(50);
}
if(vote_4== max)
{
lcd_cmd(0xCD);
lcd_data_str("P4");
delay(50);
}
}
}
voidmain()
{
ini_pin=stop_pin= 1;
vote_1 = vote_2 = vote_3= vote_4= 0;
candidate_1= candidate_2= candidate_3= candidate_4= 1;
lcd_cmd(0x38);
delay(msec);
lcd_cmd(0x0E);
delay(msec);
lcd_cmd(0x01);
delay(msec);
lcd_cmd(0x80);
delay(msec);
lcd_data_str( "Press");
delay(msec);

29. [29]
lcd_cmd(0x14);
delay(msec);
lcd_data_str("Start");
delay(msec);
delay(msec);
lcd_cmd(0xC0);
delay(msec);
lcd_data_str("to");
delay(msec);
lcd_cmd(0x14);
delay(msec);
lcd_data_str("begin");
delay(100);
while(1)
{
while(ini_pin!=0)
{
if (stop_pin== 0)
break;
}
if (stop_pin== 0)
{
break;
}
lcd_ini();
}
while(1)
{

30. [30]
results();
}
}
Advantage:-
1.The saving of considerable printing stationery and transport of large volumes of electoral
material,
2. Easy transportation, storage, and maintenance,
3. No invalid votes,
4. Reduction in polling time, resulting in fewer problems in electoral preparations, law and
order, candidates' expenditure, etc. and
5. Easy and accurate counting without any mischief at the counting centre
6. Eco friendly.
Disadvantage:-
1. Limited no. of candidates.
2. More candidates mean implies complicated circuit.
3. Microprocessor based design, which requires a no. of supporting components like
memory, peripheral interface, etc.
4. No security against illegal viewing of results, as presiding officer can view the results
without any difficulty.
5. Less user friendly due to two seven segment displays
6. Existing systemcosts high
Application:-
1. This could be used for voting purpose at any required place.
2. It is used in general elections for choosing candidates to represent people at various
stages.
3. It can be used in school, college student union elections.
4. It can be used to find the general opinion of people on various issues.
5. Anywhere where majority opinion is to be found out.

31. [31]
Future Scope:
1. Timer could be included, which could automatically end the voting after specific duration
of time.
2. Biometric Verification of voters, so that automatically it can be insured that one person is
voting once.
3. It can be made more interactive by adding sound effect (Speech) to it.
4. EEPROMcan be used to store data permanently.
5. If we make more than one EVM, each to be used at differant locations and final result will
be addition of result of all, we could think of connecting them to communicate with each
other and final result can be shown on one of the LCD.

32. [32]
BIBLIOGRAPHY
Website REFERRED
 http://www.hbeonlabs.com
 www.wikipedia.com