Electronic Voting Machine

This was just an hobby project completed on 19 May 2019 (the last voting day of the 17^th Lok Sabha Elections), as a small honour to the most crucial aspect of the world's largest democracy.

Connections

Switch c1 (for candidate 1)	pin 31 of Arduino
Switch c2 (for candidate 2)	pin 32 of Arduino
Switch c3 (for candidate 3)	pin 33 of Arduino
Switch c4 (for candidate 4)	pin 34 of Arduino
Switch no (for NOTA)	pin 8 of Arduino
Switch ne (for next candidate)	pin 10 of Arduino
Switch res (to declare results)	pin 9 of Arduino

Pin 1 (VSS) of L.C.D	GND of Arduino
Pin 2 (VDD) of L.C.D	5V of Arduino
Pin 3 (V0) of L.C.D	potentiometer center pin
Pin 4 (RS) of L.C.D	Pin2 of Arduino
Pin 5 (RW) of L.C.D	GND of Arduino
Pin 6 (EN) of L.C.D	Pin 3 of Arduino
Pin 11 (D4) of L.C.D	Pin 4 of Arduino
Pin 12 (D5) of L.C.D	Pin 5 of Arduino
Pin 13 (D6) of L.C.D	Pin 6 of Arduino
Pin 14(D7) of L.C.D	Pin 7 of Arduino
Pin 15 (A) of L.C.D	Pin 10 of Arduino
Pin 16 (K) of L.C.D	GND of Arduino

Source code^*

  

#include <LiquidCrystal.h>
char r='r';
boolean flag= false, voted=true, declare_result=false;
int c=0, initial=0, next=0,can1=0, can2=0, can3=0, can4=0, nota=0,polled=0,difference=0;
const int c1=31, c2=32, c3=33, c4=34, no=8, ne=10, result=9;
 const char pass [9] = {'P','a','s','s','w','o','r','d'};
LiquidCrystal lcd(2,3,4,5,6,7);
//////////////////////////////////////////////////////////setup()////////////////////////////////////////////setup()
void setup() {
  Serial.begin(9600);
  delay(50);
  Serial.println("Enter Password:");
  lcd.begin(16,2);
  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print(" Enter Password ");
  lcd.setCursor(0,1);
  lcd.print("   to continue  ");
}
//////////////////////////////////////////////////////////loop()////////////////////////////////////////////loop()
void loop() {
  if(flag==true){
  NextVote();
  delay(50);
  }
  if(initial==0){
    CheckPassword();
    delay(50);
  }
  delay(50);
  if(flag==true){
  AcceptVote();
  }
}
//////////////////////////////////////////////////////////NextVote()///////////////////////////////////
void NextVote(){
  //press next to accept another vote
  if(voted==true){
  while(digitalRead(ne)==HIGH){
    delay(50);
     if(digitalRead(ne)==LOW){
      delay(50);
    Serial.println("Enter voter ID (Optional)");
   lcd.setCursor(0,0);
   lcd.print("    Ready to    ");
   lcd.setCursor(0,1);
   lcd.print("  accept  vote  ");
    voted=false;
  }
  }
  }
}
//////////////////////////////////////////////////////////CheckPassword()/////////////////////////////////////////
void CheckPassword(){
  Serial.flush();
  delay(50);
  if(c>=0 && c<3){
    password();
    delay(50);
  }
   if(c>=3){
    delay(50);
    Serial.println("Due to various incorrect attempts, the software has decided to declare 'Booth Capturing'.");
    delay(50);
   lcd.setCursor(0,0);
   lcd.print("    Declared    ");
   lcd.setCursor(0,1);
   lcd.print("Booth  Capturing");    
    empty();
  }
}
//////////////////////////////////////////////////////////empty()//////////////////////////////////////////
void empty(){
  Serial.println("----------Terminate----------");
  //endless loop
 for(int i=0; i<=0; i--){
  ;
 }
}
//////////////////////////////////////////////////////////password()/////////////////////////////////
void password(){
  //check for password
  Serial.flush();
  delay(100);
  declare_result=false;
  if(Serial.available()){
    delay(50);
  for(int i=0; i<8; i++){
    char d= Serial.read();
    delay(50);
    if(d!=pass[i]){
      delay(50);
      flag=false;
    }
    if(d==pass[i]){
      delay(50);
      flag=true;
    }
  }

  //password incorrect
  if(flag == false){
    delay(50);
    Serial.println("Incorrect Password. Please retry........");
    delay(50);
    c++;
    delay(50);
    declare_result=false;
  }

  //password correct
  else{
    delay(50);
    Serial.println("Access granted.Press next to continue......");
    delay(50);
    c=0;
    initial ++;
    NextVote();
    declare_result=true;
   lcd.setCursor(0,0);
   lcd.print("Polling about to");
   lcd.setCursor(0,1);
   lcd.print("     Begin      ");
  }
  }
}
//////////////////////////////////////////////////////////AcceptVote()////////////////////////////////////////
void AcceptVote(){
  delay(100);
  if(voted==false){
    delay(100);
    //for candidate 1
    while(digitalRead(c1)==HIGH){
    if(digitalRead(c1)==LOW){
       can1++;
       Serial.println("Vote accepted");
       delay(100);
       voted=true;
       polled++;
       lcd.setCursor(0,0);
       lcd.print(" You Voted For: ");
       lcd.setCursor(0,1);
       lcd.print("  Candidate 1   ");
    }
    }
    //for candidate 2
    while(digitalRead(c2)==HIGH){
    if(digitalRead(c2)==LOW){
       can2++;
       Serial.println("Vote accepted");
       delay(100);
       voted=true;
       polled++;
       lcd.setCursor(0,0);
       lcd.print(" You Voted For: ");
       lcd.setCursor(0,1);
       lcd.print("  Candidate 2   ");
    }
    }
    //for candidate 3
    while(digitalRead(c3)==HIGH){
    if(digitalRead(c3)==LOW){
       can3++;
       Serial.println("Vote accepted");
       delay(100);
       voted=true;
       polled++;
       lcd.setCursor(0,0);
       lcd.print(" You Voted For: ");
       lcd.setCursor(0,1);
       lcd.print("  Candidate 3   ");
    }
    }
    //for candidate 4
    while(digitalRead(c4)==HIGH){
    if(digitalRead(c4)==LOW){
       can4++;
       Serial.println("Vote accepted");
       delay(100);
       voted=true;
       polled++;
       lcd.setCursor(0,0);
       lcd.print(" You Voted For: ");
       lcd.setCursor(0,1);
       lcd.print("  Candidate 4   ");
    }
    }
    //NOTA
    while(digitalRead(no)==HIGH){
    if(digitalRead(no)==LOW){
       nota++;
       Serial.println("Vote accepted");
       delay(50);
       voted=true;
       polled++;
       lcd.setCursor(0,0);
       lcd.print(" You Voted For: ");
       lcd.setCursor(0,1);
       lcd.print("     No one     ");
    }
    }
  }
  //Results
    while(digitalRead(result)==HIGH){
    if(digitalRead(result)==LOW){
       Serial.println("Preparing Results");
       delay(50);
       declare_result=false;
       DeclareResult();
       delay(100);
       voted=false;
    }
    }
  }
//////////////////////////////////////////////////////////DeclareResult()//////////////////////////////////////
void DeclareResult(){
  //release results
  lcd.clear();
  delay(50);
  if(polled>0){
  ForAll();
  }

  //can1,2,3,4==0
  if(can1==0&&can2==0&&can3==0&&can4==0){
    Serial.println("No voting done");
    lcd.clear();
    lcd.setCursor(0,1);
    lcd.print(" No voting done ");
  }

  //can1>can2,can3,can4
  else if(can1>can2 && can1>can3 && can1>can4 && can1>nota){
    Serial.println("candidate 1 wins");
   lcd.setCursor(0,0);
   lcd.print(" Maximum votes  ");
   lcd.setCursor(0,1);
   lcd.print("for: Candidate 1");
  }

  //can2>can1,can2,can3
  else if(can2>can1 && can2>can3 && can2>can4 && can2>nota){
    Serial.println("candidate 2 wins");
    lcd.setCursor(0,0);
   lcd.print(" Maximum votes  ");
   lcd.setCursor(0,1);
   lcd.print("for: Candidate 2");
  }

  //can3>can1,can2,can4
   else if(can3>can1 && can3>can2 && can3>can4 && can3>nota){
    Serial.println("candidate 3 wins");
    lcd.setCursor(0,0);
   lcd.print(" Maximum votes  ");
   lcd.setCursor(0,1);
   lcd.print("for: Candidate 3");
  }

  //can4>can1,can2,can3
   else if(can4>can1 && can4>can2 && can4>can3 && can4>nota){
    Serial.println("candidate 4 wins");
   lcd.setCursor(0,0);
   lcd.print(" Maximum votes  ");
   lcd.setCursor(0,1);
   lcd.print("for: Candidate 4");
  }

  //nota>can1,can2,can3,can4
  else if(nota>can1 && nota>can2 && nota>can3 && nota>can4){
    Serial.println("No one wins");
    lcd.clear();
    lcd.setCursor(0,1);
    lcd.print("   No one wins  ");
  }

  //can1==can2==can3==can4
  else if (can1==can4&&can1==can2&&can2==can3&&can3==can4){
    Serial.println("Tye between all candidates");
   lcd.setCursor(0,0);
   lcd.print("  Tye Between: ");
   lcd.setCursor(0,1);
   lcd.print(" All candidates ");
  }

  //can1==can2
  else if (can1==can2){
    Serial.println("Tye between candidate 1 and candidate 2");
   lcd.setCursor(0,0);
   lcd.print("  Tye Between: ");
   lcd.setCursor(0,1);
   lcd.print("Candidate 1 & 2");
  }

  //can1==can3
  else if (can1==can3){
    Serial.println("Tye between candidate 1 and candidate 3");
    lcd.setCursor(0,0);
   lcd.print("  Tye Between: ");
   lcd.setCursor(0,1);
   lcd.print("Candidate 1 & 3");
  }

  //can1==can4
  else if (can1==can4){
    Serial.println("Tye between candidate 1 and candidate 4");
    lcd.setCursor(0,0);
   lcd.print("  Tye Between: ");
   lcd.setCursor(0,1);
   lcd.print("Candidate 1 & 4");
  }

  //can2==can3
  else if (can2==can3){
    Serial.println("Tye between candidate 2 and candidate 3");
    lcd.setCursor(0,0);
   lcd.print("  Tye Between: ");
   lcd.setCursor(0,1);
   lcd.print("Candidate 2 & 3");
  }

  //can2==can4
  else if (can2==can4){
    Serial.println("Tye between candidate 2 and candidate 4");
    lcd.setCursor(0,0);
   lcd.print("  Tye Between: ");
   lcd.setCursor(0,1);
   lcd.print("Candidate 2 & 4");
  }

  //can3==can4
  else if (can3==can4){
    Serial.println("Tye between candidate 3 and candidate 4");
    lcd.setCursor(0,0);
   lcd.print("  Tye Between: ");
   lcd.setCursor(0,1);
   lcd.print("Candidate 3 & 4");
  }

  //nota==can1
  else if(nota==can1){
    Serial.println("Candidate 1 wins");
    lcd.setCursor(0,0);
   lcd.print(" Maximum votes  ");
   lcd.setCursor(0,1);
   lcd.print("for: Candidate 1");
  }

  //nota==can2
   else if(nota==can2){
    Serial.println("Candidate 2 wins");
    lcd.setCursor(0,0);
   lcd.print(" Maximum votes  ");
   lcd.setCursor(0,1);
   lcd.print("for: Candidate 2");
  }

  //nota==can3
   else if(nota==can3){
    Serial.println("Candidate 3 wins");
    lcd.setCursor(0,0);
   lcd.print(" Maximum votes  ");
   lcd.setCursor(0,1);
   lcd.print("for: Candidate 3");
  }

  //nota==can4
   else if(nota==can4){
   Serial.println("Candidate 4 wins");
   lcd.setCursor(0,0);
   lcd.print(" Maximum votes  ");
   lcd.setCursor(0,1);
   lcd.print("for: Candidate 4");
  }
  declare_result=false;
  delay(30000);
  //Signature
  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print("   EVM Made by  ");
  lcd.setCursor(0,1);
  lcd.print(" Aditya Khemka  ");
  lcd.setCursor(0,0);
  if(polled>0){
  delay(15000);
  lcd.print("   of D.B.M.S.  ");
  lcd.setCursor(0,1);
  lcd.print(" English School ");
  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print("    Thanks for  ");
  lcd.setCursor(0,1);
  lcd.print("     Voting     ");
  lcd.setCursor(0,0);
  empty();
  }
}
//////////////////////////////////////////////////////////ForAll()////////////////////////////////////////////ForAll()
void ForAll(){
  //total
  Serial.print("Total votes polled: ");
  Serial.println(polled);
  lcd.setCursor(0,0);
  lcd.print("  Total Votes   ");
  lcd.setCursor(0,1);
  lcd.print("   Polled:      ");
  lcd.setCursor(11,1);
  lcd.print(polled);
  delay(5000);

  //candidate 1
  Serial.print("Votes secured by candidate 1: ");
  Serial.println(can1);
  lcd.setCursor(0,0);
  lcd.print("Votes secured by");
  lcd.setCursor(0,1);
  lcd.print("Candidate 1:    ");
  lcd.setCursor(14,1);
  lcd.print(can1);
  delay(5000);

  //candidate 2
  Serial.print("Votes secured by candidate 2: ");
  Serial.println(can2);
  lcd.setCursor(0,0);
  lcd.print("Votes secured by");
  lcd.setCursor(0,1);
  lcd.print("Candidate 2:    ");
  lcd.setCursor(14,1);
  lcd.print(can2);
  delay(5000);

  //candidate 3
  Serial.print("Votes secured by candidate 3: ");
  Serial.println(can3);
  lcd.setCursor(0,0);
  lcd.print("Votes secured by");
  lcd.setCursor(0,1);
  lcd.print("Candidate 3:    ");
  lcd.setCursor(14,1);
  lcd.print(can3);
  delay(5000);

  //candidate 4
  Serial.print("Votes secured by candidate 4: ");
  Serial.println(can4);
  lcd.setCursor(0,0);
  lcd.print("Votes secured by");
  lcd.setCursor(0,1);
  lcd.print("Candidate 4:    ");
  lcd.setCursor(14,1);
  lcd.print(can4);
  delay(5000);
  
  //nota
  Serial.print("Total Number of Void Votes  : ");
  Serial.println(nota);
  lcd.setCursor(0,0);
  lcd.print("Total number of ");
  lcd.setCursor(0,1);
  lcd.print("Void votes:     ");
  lcd.setCursor(14,1);
  lcd.print(nota);
  delay(5000);
}

*_{This is not the latest version of the code}

Planning ahead

I am currently working to equip the device with wi-fi and a camera. For the purpose, I plan to use an esp-32 cam or esp-32 eye board, which not only has inbuilt wifi but also a 2mp camera. It can then be connected to the user's mobile phone using blynk. The user can then use their phone to send messages to the screen, look who is at their doorstep and even open the door, just with a click.