Major Report Cell Phone Based Evm

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PROJECT REPORT : CELLPHONE BASED EVM

CHAPTER: 1 INTRODUCTION
Voting is a method for a group such as a meeting or an electorate to make a decision or to express an opinion often following discussions or debates. The aim of our project is to design & develop a mobile based voting machine. In this project user can dial the specific number from any land line or mobile phone to cast his vote. Once the user is connected to the voting machine he can enter his password & choice of vote. If he has entered a valid choice & password his vote will be caste with two short duration beeps. For invalid password/choice long beep will be generated. User is allotted 15 seconds to enter his password & choice. A reset button is provided for resetting the system. A total key is provided to display the result. We have also used non-volatile memory for storing all data. EEPROM will preserve all information in case of power failure.

BACKGROUND
1.1 VOTING
Voting is a method for a group such as a meeting or an electorate to make a decision or to express an opinion often following discussions or debates.

1.1.1 Voting Techniques In India all earlier elections be it state elections or centre elections a voter used to cast his/her vote to his/her favourite candidate by putting the stamp against his/her name and then folding the ballot paper as per a prescribed method before putting it in the Ballot box. This is a long, time-consuming process and very much prone to errors. This method wanted voters to be skilled voters to know how to put a stamp, and methodical folding of ballot paper. Millions of paper would be printed and heavy ballot boxes would be loaded and unloaded to and from ballot office to polling station. All this continued till election scene was completely changed by electronic voting machine. No more ballot paper, ballot boxes, stamping, etc. all this condensed into a simple box called ballot unit of the electronic voting machine.

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PROJECT REPORT : CELLPHONE BASED EVM

1.1.2 Electronic Voting Machine The complete EVM consists mainly of two units - (a) Control Unit and (b) Balloting Unit with cable for connecting it with Control unit. A Balloting Unit caters up-to 16 candidates. Four Balloting Units linked together catering in all to 64 candidates can be used with one control unit. The control unit is kept with the Presiding Officer and the Balloting Unit is used by the voter for polling. The Balloting Unit of EVM is a small Box-like device, on top of which each candidate and his/her election symbol is listed like a big ballot paper. Against each candidate's name, a red LED and a blue button is provided. The voter polls his vote by pressing the blue button against the name of his desired candidate. 1.1.3 Tele voting Machine Tele-voting is a method of decision making and opinion polling conducted by telephone. TVM has the major unit i.e. control unit. And the heart of the machine is a microcontroller which controls all the ICs and components connected to it. It can cater large number of candidates and even further its capacity can be increased by interfacing it with 8255. In this a voter calls up the number with which the machine is connected and the system automatically activates and the voice message already stored on voice processor chip gets played and on following the voice script voter casts his vote by pressing the respective key of his phone. And the vote cast gets stored in flash memory instantly. All vote cast can be checked later with the help of couple of switches and LCD display. Reset keys are also provided to reset the machine for next time.

1.2 ADVANTAGES OF TVM
The TVMs have following advantages:  Elimination of polling queues.  Can be interfaced with PC to generate back-ups

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 The saving of considerable printing stationery and transport of large volumes of electoral material,  Easy transportation, storage, and maintenance,  No invalid votes,  Reduction in polling time.  Easy and accurate counting without any mischief at the counting centre  Eco-friendly.

1.3 COMPARE A ND CONTRAST: PAPER VOTING, EVM and TVM
We have so far discussed three different voting systems. These systems are being used or considered obsolete because of certain positive and negative points. These are summarized as follows: Device type Ballot paper EVM TVM Visual Output Ballot paper EVM TVM Security Issues Ballot paper EVM : No security provided by the system, neither during polling nor during voting. : During polling, a facility is provided to seal the machine in case of booth capturing. No further voting can be done afterwards. : Stamp on paper : Single LED against each candidate's name : LCD screen and one LED : Papers and boxes : Embedded system with Assembly code : Embedded system with Assembly code

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TVM

: machine is disconnected from the telephone line. No more calls can be received afterward.

Power Supply Ballot paper EVM TVM Capacity Ballot paper EVM TVM : As much a ballot box can hold. : 3840 Votes. : Depends on the size of flash memory attached. : No power supply required. : 6V alkaline batteries or electricity. : Electricity and supply from exchange.

1.4 EXISTING SYSTEM
But this electronic voting machine has its disadvantages too. These areas of deficiency are not much of a concern to a layman, but for an intelligent voter this must be eliminated for a secure election. The few technical disadvantages are given as: • • • Microprocessor based design, which requires a no. of supporting components like memory, peripheral interface, etc. Long polling queues at the centre. Existing system costs around 12000 INR(300$)

1.5 PROPOSED SYSTEM
All these faults motivated us to make this enhanced version of EVM. The faults which are eliminated are summarized as follows:

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• • • •

Microcontroller replaced microprocessor, which made the EVM closer to real time operation making it faster, more reliable and unique. More user friendly and interactive LCD display Proposed Module costs around Rs 2000. Elimination of polling queues had been the major factor.

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CHAPTER: 2 COMPONENTS
The “Electronic Voting Machine” consists of following main components. These are1) Switches for voting,
2) Switches for control,

3) Micro controller 4) Display 1) Switches: These are used in both voting and counting modes. In voting mode, a key of a respective candidate is pressed and the corresponding signal is sensed by micro controller. In counting mode, these are used to check the votes of respective candidates. The key given for candidate is pressed and micro controller senses the corresponding signal. There I & II . III. IV. are Clear Votes Controller switches Total Votes Switch four switches for different operations: – Two switches for clearing all the casted votes by password. – For allowing the voter to caste the vote. – For checking the total number of casted votes.

2) Micro controller: Micro controller senses the signal given from switches and decides the mode of operation. In voting mode it increments the data for corresponding key i.e. respective candidate as well as it sends signal to the buzzer to indicate one key is pressed. In counting mode micro controllers fetches data from memory location and send it to display devices.

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3) LCD: Liquid Crystal Display which is commonly known as LCD is an Alphanumeric Display. It means that it can display Alphabets, Numbers as well as special symbols. Thus LCD is a user friendly display device which can be used for displaying various messages unlike seven segment displays which can display only numbers and some of the alphabets. The only disadvantage of LCD over seven segment is that seven segment is robust display and be visualized from a longer distance as compared to LCD. Here 16 x 2 Alphanumeric Display is used; which means on this display we can display two lines with maximum of 16 characters in one line.

2.1

List of Components
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Table 2.1: List of Components

S.NO. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

LIST OF COMPONENTS 220V, 50HZ, 9V-0-9V CENTRE

QUANTITY TAP 1 1 1 1 1 1 1 1 2 2 12 8 1 1 9 1 1 2

TRANSFORMER 7805 VOLTAGE REGULATOR LIQUID CRYSTAL DISPLAY 8Ω LOUD SPEAKER 89S52 MICROCONTROLLER 24C02 EEPROM LED IN4148 DIODE IN 4007 DIODE 1000µF,16V ELECTROLYTIC CAPACITOR PUSH BUTTON SWITCH 10KΩ RESISTOR 4.7KΩ RESISTOR 10µF,100V ELECTROLYTIC CAPACITOR 10KΩ RESISTOR 1KΩ RESISTOR 3.58 MHZ CRYSTAL OSCILLATOR 27PF CERAMIC CAPACITOR

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CHAPTER:3 COMPONENT DESCRIPTION
3.1 Power Supply
These days almost all the electronic equipments include a circuit that converts AC supply into DC supply. The part of equipment that converts AC into DC is known as

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AC to DC converter. In general, at the input of the power supply is a transformer. It is followed by a rectifier, a smoothing filter and then by a voltage regulator circuit. 3.1.1 Components of Power Supply Power supply consists of four components:(i) Step-Down Transformer (ii) Rectifier (iii) Filter (iv) Voltage Regulator Block diagram of such a supply is shown below:-

TRANSFORMER

RECTIFIER

FILTER

VOLTAGE REGULATOR

Fig 3.1: Block diagram of power supply

(i) Step down Transformer A transformer in which the output (secondary) voltage is less than the input (primary) voltage is called step down transformer. Alternating current is passed through the primary coil which creates the changing magnetic field in iron core. The changing magnetic field then induces alternating current of the same frequency in the secondary coil (the output). A step down transformer has more turns of wire on the primary coil than in secondary coil which makes a smaller induced voltage in the secondary coil. (ii) Rectifier: Rectifier is defined as an electronic device used for converting A.C voltage into unidirectional voltage. A rectifier utilizes unidirectional conduction device like P-N junction diode. There are three types of rectifier:a. Half wave rectifier.

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b. Full wave centre tap rectifier.

c. Full wave bridge rectifier. (iii) Filter: The output from any of the rectifier circuits is not purely D.C but also has some A.C components, called ripples, along it. Therefore such supply is not useful for driving sophisticated electronic devices/circuits. Hence, it becomes essential to reduce the ripples from the pulsating D.C supply available from rectifier circuits to the minimum. This is achieved by using a filter or smoothing circuit which removes the A.C components and allows only the D.C component to reach the load. A filter circuit should be placed between the rectifier and the load.

(iv) Voltage Regulator: Voltage Regulator (regulator), usually having three legs, converts varying input voltage and produces a constant regulated output voltage. 7805 voltage regulator has three pins:a. Input:- For 7805 the rectified and filtered voltage coming at this pin must be between 8 to 18V in order to get stable 5V DC output at the output pin.

INPUT

7805 OUTPOUTPUT

GND

Fig. 3.2: Pin configuration of voltage regulator

b. Ground:- This pin is connected to the ground of the circuit to which this 5V DC supply is provided. c. Output:- If the input voltage at input pin is between 8-18V then at the output pin a stable 5V DC voltage will be available.

3.1.2 5V DC Power Supply Using Full Wave Center Tap Rectifier

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The transformer supplies the source voltage for two diode rectifiers, D1 and D2. This transformer has a center-tapped, low-voltage secondary winding that is divided into two equal parts (W1 and W2). W1 provides the source voltage for D1, and W2 provides the source voltage for D2. The connections to the diodes are arranged so that the diodes conduct on alternate half cycles. When the centre tap is grounded, the voltages at the opposite ends of the secondary windings are 180 degrees out of phase with each other. Thus, when the voltage at point A is positive with respect to ground, the voltage at point B is negative with respect to ground. Let's examine the operation of the circuit during one complete cycle.

During the first half cycle (indicated by the solid arrows), the anode of D1 is positive with respect to ground and the anode of D2 is negative. As shown, current flows from ground (center tap) to point A, through diode D1 to point B and to point D. When D1 conducts, it acts like a closed switch so that the positive half cycle is felt across the load (RL).

During the second half cycle (indicated by the dotted lines), the polarity of the applied voltage has reversed. Now the anode of D2 is positive with respect to ground and the anode of D1 is negative. Now only D2 can conduct. Current now flows, as shown, from point C to point B through diode D2 then to point F and back to point D.

Now during both the cycles the capacitor C1 quickly charges to the peak voltage but when the input voltage becomes less than peak voltage the capacitor discharges through load resistance and loses charge. But because of large load resistance the discharging time is large and hence capacitor does not have sufficient time to discharge appreciably. Due to this the capacitor maintains a sufficiently large voltage across the load.

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i/p

Fig. 3.3: Center-tap full-wave rectifier

The voltage across the capacitor is applied to 7805 voltage regulator which provides a constant 5V D.C. voltage at its output.

Fig. 3.4: Output waveforms of centre-tap full-wave rectifier

3.2 Microcontroller 89S52
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

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memory programmer. 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. .

3.2.1 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 Fast Programming Time

               

3.2.2 Block Diagram

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Fig 3.5: Block Diagram of microcontroller

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3.2.3 Pin Description

Fig 3.6: Pin Diagram of microcontroller

VCC : GND :

Supply voltage Ground.

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Port 0 Port 0 is an 8-bit open drain bidirectional 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 low-order 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 pull-ups are required during program verification. Port 1 Port 1 is an 8-bit bidirectional I/O port with internal pull-ups. 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 pull-ups and can be used as inputs. As inputs, Port 1 pins that are externally being pulled low will source current (IIL) because of the internal pull-ups. In addition, P1.0 and P1.1 can be configured to be the timer/counter 2 external count input (P1.0/T2) and the timer/counter 2 trigger input (P1.1/T2EX), respectively. Port 1 also receives the low-order address bytes during Flash programming and verification. Port 2 Port 2 is an 8-bit bidirectional I/O port with internal pull-ups. 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 pull-ups 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 pull-ups. Port 2 emits the high-order address byte during fetches from external program memory and during accesses to external data memory that use 16-bit addresses. In this application, Port 2 uses strong internal pull-ups when emitting 1s.

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Port 3 : Port 3 is an 8-bit bidirectional I/O port with internal pull-ups. The Port 3 output buffers can sink/source four TTL inputs. When 1s are written to Port 3 pins, they are pulled high by the internal pull-ups and can be used as inputs. As inputs, Port 3 pins that are externally being pulled low will source current (IIL) because of the pull-ups. Port 3 receives some control signals for Flash programming and verification. Port 3 also serves the functions of various special features of the AT89S52. ALE/PROG : Address Latch Enable (ALE) is an output pulse for latching the low byte of the address during accesses to external memory. This pin is also the program pulse input (PROG) during Flash programming. In normal operation, ALE is emitted at a constant rate of 1/6 the oscillator frequency and may be used for external timing or clocking purposes. Note, however, that one ALE pulse is skipped during each access to external data memory. If desired, ALE operation can be disabled by setting bit 0 of SFR location 8EH. With the bit set, ALE is active only during a MOVX or MOVC instruction. Otherwise, the pin is weakly pulled high. Setting the ALE-disable bit has no effect if the microcontroller is in external execution mode. PSEN Program Store Enable (PSEN) is the read strobe to external program memory. When the AT89S52 is executing code from external program memory, PSEN is activated twice each machine cycle, except that two PSEN activations are skipped during each access to external data 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. Note, however, that if lock bit 1 is programmed, EA will be internally latched on reset. EA should be strapped to VCC for Internal program executions. This pin also receives the 12-volt programming enable voltage (VPP) during Flash programming.

XTAL1

Input to the inverting oscillator amplifier and input to the internal clock operating circuit.

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XTAL2

Output from the inverting oscillator amplifier.

3.3 Liquid Crystal Display
Liquid Crystal Display also called as LCD is very helpful in providing user interface as well as for debugging purpose. These LCD's are very simple to interface with the controller as well as are cost effective.

Figure 8.FFFF
Fig 3.7: LCD

The most commonly used ALPHANUMERIC displays are 1x16 (Single Line & 16 characters), 2x16 (Double Line & 16 character per line) & 4x20 (four lines & Twenty characters per line). The LCD requires 3 control lines (RS, R/W & EN) & 8 (or 4) data lines. The number of data lines depends on the mode of operation. If operated in 8-bit mode then 8 data lines + 3 control lines i.e. total 11 lines are required. And if operated in 4-bit mode then 4 data lines + 3 control lines i.e. 7 lines are required. How do we decide which mode to use? It’s simple if you have sufficient data lines you can go for 8 bit mode & if there is a time constrain i.e. display should be faster then we have to use 8-bit mode because basically 4-bit mode takes twice as more time as compared to 8-bit mode.

3.3.1 Pin Description

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fig 3.8: Pin Description of LCD Table 3.1: Pin Description of LCD

Pin 1 2 Pin 3 4 5 6 7-14 15 16

Symbol Vss Vdd Symbol Vo RS R/W En DB0-DB7 A/Vee K

Function Ground Supply Voltage Function Contrast Setting Register Select Read/Write Select Chip Enable Signal Data Lines Gnd for the backlight Vcc for backlight

1. RS (Register Select) When RS is low (0), the data is to be treated as a command. When RS is high (1), the data being sent is considered as text data which should be displayed on the screen.

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2. R/W (Read/Write) When R/W is low (0), the information on the data bus is being written to the LCD. When RW is high (1), the program is effectively reading from the LCD. Most of the times there is no need to read from the LCD so this line can directly be connected to GND thus saving one controller line. 3. E (enable) The ENABLE pin is used to latch the data present on the data pins. A HIGH - LOW signal is required to latch the data. The LCD interprets and executes our command at the instant the EN line is brought low. If you never bring EN low, your instruction will never be executed. 4. D0-D7 The 8 bit data pins D0-D7 are used to send information to the LCD or read the contents of the LCD’s internal registers. .To display any character on LCD micro controller has to send its ASCII value to the data bus of LCD. For e.g. to display 'AB' microcontroller has to send two hex bytes 41h and 42h respectively LCD display used here is having 16x2 size. It means 2 lines each with 16 characters.

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3.4 AT24c02 Flash Memory
The AT24C01A/02/04/08A/16A provides 1024/2048/4096/8192/16384 bits of serial electrically erasable and programmable read-only memory (EEPROM) organized as 128/256/512/1024/2048 words of 8 bits each. The device is optimized for use in many industrial and commercial applications where low power and low voltage operation are essential. The AT24C01A/02/04/08A/16A is available in space-saving 8-lead PDIP, 8lead JEDEC SOIC, 8-lead Ultra Thin Mini-MAP (MLP 2x3), 5-lead SOT23 (AT24C01A/AT24C02/AT24C04), 8-lead TSSOP, and 8-ball dBGA2 packages and is accessed via a Two-wire serial interface. In addition, the entire family is available in 2.7V (2.7V to 5.5V) and 1.8V (1.8V to 5.5V) versions. 3.4.1 Features • Low-voltage and Standard-voltage Operation – 2.7 (VCC = 2.7V to 5.5V) – 1.8 (VCC = 1.8V to 5.5V) • • • • • • • • • • Internally Organized 128 x 8 (1K), 256 x 8 (2K), 512 x 8 (4K), 1024 x 8 (8K) or 2048 x 8 (16K) Two-wire Serial Interface Schmitt Trigger, Filtered Inputs for Noise Suppression Bidirectional Data Transfer Protocol 100 kHz (1.8V) and 400 kHz (2.7V, 5V) Compatibility Write Protect Pin for Hardware Data Protection 8-byte Page (1K, 2K), 16-byte Page (4K, 8K, 16K) Write Modes Partial Page Writes Allowed Self-timed Write Cycle (5 ms max) High-reliability – Endurance: 1 Million Write Cycles – Data Retention: 100 Years

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3.4.2 Block Diagram

Fig 3.9: Block Diagram of EEPROM

3.4.3 Pin Description

Fig 3.10: Pin diagram of EEPROM

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Serial Clock (SCL): The SCL input is used to positive edge clock data into each EEPROM device and negative edge clock data out of each device. Serial Data (SDA): The SDA pin is bidirectional for serial data transfer. This pin is open-drain driven and may be wire-ORed with any number of other open-drain or open collector devices. Device/Page Addresses (A2, A1, and A0): The A2, A1 and A0 pins are device address inputs that are hard wired for the AT24C01A and the AT24C02. As many as eight 1K/2K devices may be addressed on a single bus system (device addressing is discussed in detail under the Device Addressing section). The AT24C04 uses the A2 and A1 inputs for hard wire addressing and a total of four 4K devices may be addressed on a single bus system. The A0 pin is a no connect and can be connected to ground. The AT24C08A only uses the A2 input for hardwire addressing and a total of two 8K devices may be addressed on a single bus system. The A0 and A1 pins are no connects and can be connected to ground. The AT24C16A does not use the device address pins, which limits the number of devices on a single bus to one. The A0, A1 and A2 pins are no connects and can be connected to ground.
Table 3.2: Pin Description of Flash Memory

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Write Protect (WP): The AT24C01A/02/04/08A/16A has a Write Protect pin that provides hardware data protection. The Write Protect pin allows normal Read/Write operations when connected to ground (GND). When the Write Protect pin is connected to VCC, the write protection feature is enabled.

3.5 Voltage Regulator
Voltage regulator ICs are available with fixed (typically 5, 12 and 15V) or variable output voltages. The maximum current they can pass also rates them. Negative voltage regulators are available, mainly for use in dual supplies. Most regulators include some automatic protection from excessive current and overheating (thermal protection). Many of fixed voltage regulator ICs has 3 leads. They include a hole for attaching a heat sink if necessary.

Fig 3.11: 7805 Voltage Regulator

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3.5.1 Features • Output current in Excess of 1.0 A • No external component required • Internal thermal overload protection • Internal short circuit current limiting • Output transistor safe-area compensation • Output voltage offered in 2% and 4% tolerance • Available in surface mount D2PAK and standard 3-lead transistor packages • Previous commercial temperature range has been extended to a junction temperature range of -40 degree C to +125 degree C.

3.6 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.

Fig 3.12: Diode & Diode symbol

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 i.e. N to P direction. Visually the identification of the diode`s terminal can be done by identifying he silver/black line. The silver/black line is the negative terminal (cathode) and the other terminal is the positive terminal (cathode).

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3.6.1 Application • • • Diodes: Rectification, free-wheeling, etc Zener diode: Voltage control, regulator etc. Tunnel diode: Control the current flow, snobbier circuit, etc.

3.7 Resistors
The flow of charge through any material encounters an opposing force similar in many respects to mechanical friction. This opposing force is called resistance of the material .in some electric circuit resistance is deliberately introduced in form of resistor. Resistor used fall in three categories , only two of which are colour coded which are metal film and carbon film resistor .the third category is the wire wound type ,where value are generally printed on the vitreous paint finish of the component. Resistors are in ohms and are represented in Greek letter omega, looks as an upturned horseshoe. Most electronic circuit require resistors to make them work properly and it is obliviously important to find out something about the different types of resistors available. Resistance is measured in ohms, the symbol for ohm is an omega ohm. 1 ohm is quite small for electronics so resistances are often given in kohm and Mohm. Resistors used in electronics can have resistances as low as 0.1 ohm or as high as 10 Mohm.

Fig 3.13: Resistor symbol & resistor

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3.8 Capacitors
In a way, a capacitor is a little like a battery. Although they work in completely different ways, capacitors and batteries both store electrical energy. If you have read How Batteries Work, then you know that a battery has two terminals. Inside the battery, chemical reactions produce electrons on one terminal and absorb electrons at the other terminal. 3.8.1 Basic Like a battery, a capacitor has two terminals. Inside the capacitor, the terminals connect to two metal plates separated by a dielectric. The dielectric can be air, paper, plastic or anything else that does not conduct electricity and keeps the plates from touching each other. You can easily make a capacitor from two pieces of aluminum foil and a piece of paper. It won't be a particularly good capacitor in terms of its storage capacity, but it will work.

Fig 3.14: Capacitor & capacitor symbol

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3.9 LED
LED falls within the family of P-N junction devices. The light emitting diode (LED) is a diode that will give off visible light when it is energized. In any forward biased P-N junction there is, with in the structure and primarily close to the junction, a recombination of hole and electrons. This recombination requires that the energy possessed by the unbound free electron be transferred to another state. The process of giving off light by applying an electrical source is called electroluminescence.

Fig 3.15: LED & LED symbol

LED is a component used for indication. All the functions being carried out are displayed by led .The LED is diode which glows when the current is being flown through it in forward bias condition. The LEDs are available in the round shell and also in the flat shells. The positive leg is longer than negative leg.

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3.10 Crystal Oscillators
Crystal oscillators are oscillators where the primary frequency determining element is a quartz crystal. Because of the inherent characteristics of the quartz crystal the crystal oscillator may be held to extreme accuracy of frequency stability. Temperature compensation may be applied to crystal oscillators to improve thermal stability of the crystal oscillator. Crystal oscillators are usually, fixed frequency oscillators where stability and accuracy are the primary considerations. For example it is almost impossible to design a stable and accurate LC oscillator for the upper HF and higher frequencies without resorting to some sort of crystal control. Hence the reason for crystal oscillators. The frequency of older FT-243 crystals can be moved upward by crystal grinding.

Fig 3.16: crystal oscillator & symbol

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CHAPTER:4 PROJECT DESCRIPTION
4.1 Circuit Diagram

Fig 4.1: Circuit Diagram of EVM

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4.2 Block Diagram:

230V AC

Step Down T/F

Full Wave Bridge Rectifier

Voltage Regulator
+5VDC/50 0mA

DTMF Decoder (MM8870)

Microcontroller AT89C2051

LCD Display

MOBILE PHONE

EEPROM (24C16)

Figure No. 4.2 : Block Diagram of EVM

31 DEPARTMENT OF ECE ( MIT , MEERUT)

PROJECT REPORT : CELLPHONE BASED EVM

4.3 PCB Layout

Fig 4.3: PCB Layout

32 DEPARTMENT OF ECE ( MIT , MEERUT)

PROJECT REPORT : CELLPHONE BASED EVM

4.4 Functional Description
The function of the pins of microcontroller AT89S52 used in the electronic voting machine can be described as follows: Pin no 1,2,3,4 of PORT 1 are connected to get the vote data input for four different candidates.  Pin no 5,6,7,8 are connected to four push-button switches to check the vote data casted for individual candidate.  Pin no 9 is connected to the reset button to reset the microcontroller automatically when we switch on the power. It is a Power on reset.  Pin no 10 of PORT 3 is connected to a push-button switch to check the total vote caste for all the candidates.  Pin no 11 and 12 of PORT 3 are connected to two push-button switches to reset or clear all the vote data. To reset the data firstly we will press the R-1 button then press the R-2 button and again press the R-1 button. Then all the vote data has to be cleared from the AT24c02 flash memory.  Crystal is connected to the pin no 18(XTAL 1) and pin no 19(XTAL 2) providing 11.0592 MHz frequency.   Pin no 20 is connected to the ground (GND). Pin no 21 and 22 of PORT 2 are connected to pin no 5(SDA- serial data) and pin no 6 (SCL- serial clock input) of AT24c02 flash memory.  Pin no 26, 27, 28 of PORT 2 are connected to the pin no 4, 5, 6 of LCD display. Pin no 26 is connected to RS (register select), pin no 27 is connected to R/W (read/write select) and pin no 28 is connected to En(chip enable signal) of LCD.  Pin no 31( EA/Vpp) should be strapped to VCC for internal program executions, this pin also receives the 12-volt programming enable voltage (VPP) during flash programming.  Pin no 32 – 39 of PORT 0 are connected to the DB0-DB7 (8-bit) data lines of LCD display.



33 DEPARTMENT OF ECE ( MIT , MEERUT)

PROJECT REPORT : CELLPHONE BASED EVM

4.5 Working of Project
The working of this project is controlled by a microcontroller ATMEL AT89S52 and EEPROM is used for memory storage. The project works in the following ways: 1. Switch on power supply. 2. Message ‘VOTING MACHINE’ , ‘INDIA VOTING’ will appear on LCD. 3. Controller switch is pressed after which the message ‘Cast the Vote’ appears. 4. After casting the vote, one hears the buzzer after which no other votes will be casted until the controller button is again pressed. 5. To check the number of vote press the button on the PCB and number of votes of each candidate & total number of vote will appear on LCD. 6. Two memory clear pins are provided for clearing the EEPROM.

34 DEPARTMENT OF ECE ( MIT , MEERUT)

PROJECT REPORT : CELLPHONE BASED EVM

4.6 PROBLEM FACED
      First problem that was in making the circuit of METRO TRAIN PROTOTYPE that, it is difficult to match time with rotation of stepper motor & LCD. Second problem is faced due to redundancy in handling the rotation of STEPPER MOTOR We have to take extra care while soldering 2 line LCD During soldering, many of the connection become short cktd. So we desolder the connection and did soldering again. A leg of the crystal oscillator was broken during mounting. So it has to be replaced. LED`s get damaged when we switched ON the supply so we replace it by the new one.

4.7TROUBLESHOOT
    Care should be taken while soldering. There should be no shorting of joints. Proper power supply should maintain. Project should be handled with care since IC are delicate Component change and check again circuit

35 DEPARTMENT OF ECE ( MIT , MEERUT)

PROJECT REPORT : CELLPHONE BASED EVM

4.8 C Code
Program code is to be written in embedded C code and after this, the code is converted into hex code using Keil µ vision3 and transfer onto the blank chip AT89s52 microcontroller with the help of programmer kit SPIPGM37. The program code using AT89s52 microcontroller chip is as follows: #include<reg52.h> #define lcdport P0 sbit rs=P2^2; sbit rdwr=P2^1; sbit lcde=P2^0; sbit cand1=P1^0; sbit cand2=P1^1; sbit cand3=P1^2; sbit cand4=P1^3; sbit cand5=P1^4; sbit cand6=P1^5; sbit cand7=P1^6; sbit cand8=P1^7; sbit party1=P3^0; sbit party2=P3^1; sbit party3=P3^2; sbit party4=P3^3; sbit party5=P3^4; bit vote_switchflag; unsigned int cand1count,cand2count,cand3count,cand4count,cand5count,cand6count,cand7count,ca nd8count;

36 DEPARTMENT OF ECE ( MIT , MEERUT)

PROJECT REPORT : CELLPHONE BASED EVM

/****************FUNCTION FOR SWAPPING LSBYTE AND MSBYTE OF THE DATA***************/ unsigned char xch(unsigned char data1) { unsigned char temp,temp1; temp=data1; data1=data1>>4; temp1=data1; data1=temp; data1=data1<<4; data1=data1|temp1; return(data1); } /************ delay for 20 micro second **********************************************/ void delay() { unsigned char i,j; for(i=0;i<80;i++) { for(j=0;j<120;j++) {} }} /***************** FUNCTION FOR SENDING LCD COMMANDS***********************************/ void send_command(unsigned char data1) {

37 DEPARTMENT OF ECE ( MIT , MEERUT)

PROJECT REPORT : CELLPHONE BASED EVM

unsigned char newdata; rs=0; delay(); lcde=1; delay(); lcdport=data1; lcde=0; delay(); lcde=1; newdata=xch(data1); lcdport=newdata; delay(); lcde=0; delay(); rs=1; } /************************** FUNCTION FOR WRITING DATA ON THE LCD***********************/ void send_data(unsigned char data1) { unsigned char newdata; rs=1; delay(); lcde=1; delay(); lcdport=data1; lcde=0; delay(); lcde=1;

38 DEPARTMENT OF ECE ( MIT , MEERUT)

PROJECT REPORT : CELLPHONE BASED EVM

newdata=xch(data1); lcdport=newdata; delay(); lcde=0; delay(); rs=0; }

/*********** COMMAND FOR BRINGING LCD CURSOR ON SECOND LINE ***************************/ void next_line() { send_command(0xc0); delay(); }

/* FUNCTION FOR DISPLAYING DATA ON THE LCD *************************************/ void dispslogan(unsigned char *p) { unsigned char data1; while(*p) { data1=*p; send_data(data1); p++; } }

39 DEPARTMENT OF ECE ( MIT , MEERUT)

PROJECT REPORT : CELLPHONE BASED EVM

/********************** INITIALIZATION OF LCD ***********************************/ void lcdinit() { clr_lcd(); delay(); send_command(0x28); delay(); send_command(0x28); delay(); send_command(0x06); delay(); send_command(0x0e); delay(); clr_lcd(); } void count_display(unsigned int data1) { unsigned int a[4]; int i=0; while(data1!=0) { a[i++]=data1%10; data1=data1/10; } i--; for(;i>=0;i--) //DISPLAY ON/OFF //ENTRY MODE /*FUNCTION SET */ send_command(0x28);

40 DEPARTMENT OF ECE ( MIT , MEERUT)

PROJECT REPORT : CELLPHONE BASED EVM

send_data(a[i] + 48); } void cand1chk() { if(cand1==0 && vote_switchflag==1) { next_line(); dispslogan("CONG_OK vote_switchflag=0; cand1count++; }} void cand2chk() { if(cand2==0 && vote_switchflag==1) { next_line(); dispslogan("BJP_OK vote_switchflag=0; cand2count++; }} void cand3chk() { if(cand3==0 && vote_switchflag==1) { next_line(); dispslogan("RSS_OK vote_switchflag=0; cand3count++; }} void cand4chk() { if(cand4==0 && vote_switchflag==1) "); "); ");

41 DEPARTMENT OF ECE ( MIT , MEERUT)

PROJECT REPORT : CELLPHONE BASED EVM

{ next_line(); dispslogan("BSP_OK vote_switchflag=0; cand4count++; }} ~*~*~*~*~*~*~*~ ");

42 DEPARTMENT OF ECE ( MIT , MEERUT)

PROJECT REPORT : CELLPHONE BASED EVM

CHAPTER:5 CONCLUSION
5.1 Area of Applications


Fast track voting which could be used in small scale elections, like resident welfare association, “panchayat” level election and other society level elections.



It could also be used to conduct opinion polls during annual share holders meeting.



It could also be used to conduct general assembly elections where number of candidates are less than or equal to eight in the current situation.



It is used in various TV serials as for public opinion.

5.2 Future Scope
• • Number of candidates could be increased by using other microcontroller. It could be interfaced with printer to get the hard copy of the result almost instantly from the machine itself. • It could also be interfaced with the personal computer and result could be stored in the central server and its backup could be taken on the other backend servers. • Again, once the result is on the server it could be relayed on the network to various offices of the election conducting authority. Thus our project could make the result available any corner of the world in a matter of seconds.

43 DEPARTMENT OF ECE ( MIT , MEERUT)

PROJECT REPORT : CELLPHONE BASED EVM

~*~*~*~*~*~*~*

APPENDIX
ABBREVIATIONS Sr. no.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21

Short form
EVM TVM LCD LED DC AC GND VCC OSC PSW ALU RAM ROM PC TTL ALE PROG PSEN PCB T/F EEPROM

Details
Electronic Voting Machine Tele Voting Machine Liquid Crystal Display Light Emitting Device Direct current Analog current Ground Voltage Supply (+5 V) Oscillator Program Status Word Airthematic & Logical Unit Read Access Memory Read Only Memory Program Counter Transistor Transistor Logic Address Latch Enable Program Program Status Enable Printed Circuit Board Transformer Electrically Erasable & programmable Read Only Memory

~*~*~*~*~*~*~*~

44 DEPARTMENT OF ECE ( MIT , MEERUT)

PROJECT REPORT : CELLPHONE BASED EVM

REFRENCES
 Muhammad Ali Mazidi , Janice Gillispie Mazidi, Rolin D. Mckinlay. Second edition, “THE 8051 MICROCONTROLLER AND EMBEDDED SYSTEM” K. J. Ayala. Third edition, “The 8051 MICROCONTROLLER” Tutorial on microcontroller: www.8051projects.net/microcontroller_tutorials/ Tutorial on LCD: www.8051projects.net/lcd-interfacing/

 



WEBSITES
         www.atmel.com www.seimens.com www.howstuffworks.com www.alldatasheets.com www.efyprojects.com www.google.com www.eci.gov.in/Audio_VideoClips/presentation/EVM.ppt www.rajasthan.net/election/guide/evm.htm www.indian-elections.com/electoralsystem/electricvotingmachine.html

~*~*~*~*~*~*~*~

45 DEPARTMENT OF ECE ( MIT , MEERUT)

PROJECT REPORT : CELLPHONE BASED EVM

46 DEPARTMENT OF ECE ( MIT , MEERUT)

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