#include <Keypad.h>
#include <LiquidCrystal_I2C.h>
#include <Wire.h>
LiquidCrystal_I2C lcd(0x27,16,2);
const byte num_row=4;
const byte num_col=4;
String text="";
int count=0;
int a=0;
int r=13;
int g=3;
char key[num_row][num_col]={
  {'1','2','3','A'},
  {'4','5','6','B'},
  {'7','8','9','c'},
  {'*','0','E','D'}
};
byte rowpin[num_row]={12,11,10,9};
byte colpin[num_col]={7,6,5,4};
Keypad keypad=Keypad(makeKeymap(key),rowpin,colpin,num_row,num_col);
void setup() {
  // put your setup code here, to run once:
lcd.begin(16,2);
lcd.backlight();
pinMode(3, OUTPUT);
pinMode(13, OUTPUT);
lcd.setCursor(0,0);
lcd.print("WELCOME");
lcd.setCursor(0,1);
lcd.print("SECURITY SYSTEM");
delay(3000);
lcd.clear();
}
void loop() {
  // put your main code here, to run repeatedly:
char key=keypad.getKey();
if(key)
{
  text+=key;
count++;
if(count>5)
{
  lcd.clear();
  lcd.print("invaid lenght");
  count=0;
}
lcd.print("*");
if(key=='A')
{
  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print("Enter password");
  lcd.setCursor(3,1);
  text="";
}
else if(key=='*')
{
  lcd.clear();
  a=0;
  count=0;
  digitalWrite(r, LOW);
  digitalWrite(g, LOW);
}
if(key=='E')
{
  lcd.setCursor(3,1);
  lcd.clear();
if(text=="9876E")
{
  lcd.print("vaild password");
  digitalWrite(g, HIGH);
  digitalWrite(r,LOW);
  delay(3000);
  digitalWrite(g,LOW);
  count=0;
  lcd.clear();
}
else
{
  lcd.print("invalid pass...");
  digitalWrite(r,HIGH);
  digitalWrite(g,LOW);
  delay(2000);
  digitalWrite(r, LOW);
  lcd.clear();
a++;
}
if(a==3)
{
  digitalWrite(r, HIGH);
  delay(2000);
  digitalWrite(g, LOW);
a=0;
}
}
}
}