Password Protected Door Lock Using Arduino

The project comprises of Arduino mega,a motor, a keypad, a buzzer,lcd, potential meter, red led and green led.After uploading the hex file ,the lcd starts.

Step 1: Welcome Note Prompts You to Enter Password

The welcome note prompts the user to enter password to unlock door.

Step 2: Validation of Password

The user enters the password.When the correct password is entered, the green led lights and the motor rotates thus opening the door.

Step 3: Invalid Password

In case the user enters the wrong password, the red led lights and the buzzer sounds. In this case the door does not open.

Step 4: Code

#include <Keypad.h>
#include <LiquidCrystal.h>

#include<Wire>
int greenLed=22;
int redLed=23;
int motorPin=24;
int piezoPin=25;
char* ourCode="1234";
int currentPosition=0;
const byte rows=4;
const byte cols=3;
char keys[rows][cols]={
  {'1','2','3'},
  {'4','5','6'},
  {'7','8','9'},
  {'*','0','#'}
};
byte rowPins[rows]={13,10,9,8};
byte colPins[cols]={7,6,1};
Keypad keypad=Keypad(makeKeymap(keys),rowPins,colPins,rows,cols);
LiquidCrystal Lcd (12,11,5,4,3,2);
void setup()
{
  Lcd.begin(16,2);
  
  //lcd.init();
  
  displayCodeEntryScreen();
  pinMode(piezoPin,OUTPUT);
  pinMode(motorPin,OUTPUT);
  pinMode(redLed,OUTPUT);
  pinMode(greenLed,OUTPUT);
  digitalWrite(redLed,LOW);
  digitalWrite(greenLed,LOW);
  
  // put your setup code here, to run once:
}
void loop() {
  int l;
  char key=keypad.getKey();
  
  if(int(key)!=0){
    Lcd.setCursor(10,0);
    Lcd.print("       ");
    Lcd.setCursor(10,0);
    
    for(l=0;l<=currentPosition;++l)
    {Lcd.print("*");}
    if(key==ourCode[currentPosition])
    {
      ++ currentPosition;
      if(currentPosition==4)
      {unlockDoor();
      currentPosition=0;
      }
    }
    else{invalidCode();
  currentPosition=0;
}
    
      }
  }
  void invalidCode()
  {
    digitalWrite(redLed,HIGH);
     digitalWrite(motorPin,LOW);
     digitalWrite(piezoPin,HIGH);
  clearScreen();
  Lcd.setCursor(0,0);
  Lcd.print("ACCESS DENIED!");
  Lcd.setCursor(0,1);
  Lcd.print("INVALID CODE ");
  delay(5000);
 digitalWrite(redLed,LOW);
 digitalWrite(piezoPin,LOW);
  displayCodeEntryScreen();
  }
  
  void unlockDoor()
  { 
    digitalWrite(greenLed,HIGH);
  clearScreen();
   Lcd.setCursor(0,0);
   Lcd.print(" ACCESS GRANTED ");
   Lcd.setCursor(0,1);
  Lcd.print(" WELCOME!! ");
  digitalWrite(motorPin,HIGH);
  delay(5000);
  digitalWrite(greenLed,LOW);
  digitalWrite(motorPin,LOW);
  displayCodeEntryScreen();
  }
  void displayCodeEntryScreen()
  {
    clearScreen();
     Lcd.setCursor(0,0);
    Lcd.print("Hallow,welcome");
     Lcd.setCursor(0,1);
     Lcd.print("Enter  code");
    
  }
  void clearScreen()
  { 
    Lcd.setCursor(0,0);
    Lcd.print("                ");
     Lcd.setCursor(0,1);
     Lcd.print("                 ");
  
    
}
  // put your main code here, to run repeatedly: