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Cellphone based voting machine project report

Aug 19, 2014

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Engineering

India is world’s largest democracy. Fundamental right to vote or simply voting in elections forms the basis of Indian democracy.

In India all earlier elections a voter used to cast his vote by using ballot paper. This is a long, time-consuming process and very much prone to errors.

This situation 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.

Cell phone based voting machine is capable of saving considerable printing stationery and
transport of large volumes of electoral material. It is easy to transport, store, and maintain. It completely rules out the chance of invalid votes. Its use results in reduction of polling time, resulting in fewer problems in electoral preparations, law and order, candidates' expenditure, etc. and easy and accurate counting without any mischief at the counting centre.

  • 1 CHAPTER 1 INTRODUCTION 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 favorite 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. 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.
  • 2 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 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 : Papers and boxes
  • 3 EVM : Embedded system with Assembly code TVM : Embedded system with Assembly code Visual Output Ballot paper : Stamp on paper EVM : Single LED against each candidate's name TVM : LCD screen and one LED Security Issues Ballot paper : No security provided by the system, neither during polling nor during voting. EVM : During polling, a facility is provided to seal the machine in case of booth capturing. No further voting can be done afterwards. TVM : machine is disconnected from the telephone line. No more calls can be received afterward. Power Supply Ballot paper : No power supply required. EVM : 6V alkaline batteries or electricity. TVM : Electricity and supply from exchange. Capacity Ballot paper : As much a ballot box can hold. EVM : 3840 Votes. TVM : Depends on the size of flash memory attached.
  • 4 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: 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.
  • 5 CHAPTER 2 POWER SUPPLY 2.1 INTRODUCTION 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 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. 2.2 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:- Fig. 2.1 Block diagram TRANSFORME R VOLTAGE REGULATO R RECTIFIER FILTER
  • 6 2.2.1 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. The transformer equation relates the number of turns of wire to the difference in voltage between the primary and secondary coils. Vp /Vs = Np /Ns ...(2.1) Vp is the voltage in the primary coil. Vs is the voltage in the secondary coil. Np is the number of turns of wire on the primary coil. Ns is the number of turns of wire on the secondary coil. 2.2.2 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. b. Full wave center tap rectifier. c. Full wave bridge rectifier.
  • 7 2.2.3 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. 2.2.4 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 O OUTPUT GND Fig. 2.2 Pin configuration 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. 7805 can give +5V output at about 150 mA current, but it can be increased to 1A when good cooling is added to 7805 regulator chi 7805
  • 8 2.3 5V DC POWER SUPPLY USING FULL WAVE CENTER TAP RECTIFIER 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 center 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 pola