Introduction: 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: