/* Arduino Security System with the Keypad and LCD  
Simple one-digit password 
*/      
#include <LiquidCrystal.h> //include LCD library 
#include <Keypad.h> //include keypad library 
#define redLED 11 //define the LED pins 
#define greenLED 12 
const byte rows = 4; //number of the keypad rows 
const byte cols = 4; // number of the keypad columns 
char keyMap [rows] [cols] = { //define the symbols on the buttons of the keypad 
 {'1', '2', '3', 'A'}, 
 {'4', '5', '6', 'B'}, 
 {'7', '8', '9', 'C'}, 
 {'*', '0', '#', 'D'} 
}; 
char password ='6'; //create a password 
byte rowPins [rows] = {1, 2, 3, 4}; // digital pins related to the row pins of the keypad 
byte colPins [cols] = {5, 6, 7, 8}; // digital pins related to the column pins of the keypad 
Keypad myKeypad = Keypad( makeKeymap(keyMap), rowPins, colPins, rows, cols); 
LiquidCrystal lcd (A0, A1, A2, A3, A4, A5); // pins of the LCD. (RS, E, D4, D5, D6, D7) 
void setup(){ 
 lcd.begin(16, 2); 
 pinMode(redLED, OUTPUT); //set the LED as an output 
 pinMode(greenLED, OUTPUT); 
 setLocked (true); //state of the password 
}
void loop(){ 
 // char whichKey = myKeypad.getKey(); //define which key is pressed with getKey 
 lcd.setCursor(0, 0); 
 lcd.print(" Welcome"); 
 lcd.setCursor(0, 1); 
 lcd.print(" Enter Password"); 

char whichKey = myKeypad.waitForKey(); //define which key is pressed with getKey 
 if((whichKey == '*') || (whichKey == '#') || (whichKey == 'A') || (whichKey == 'B') || (whichKey == 'C')  ||( whichKey == 'D')) 
 { 
 // location=0; 
 setLocked (true); 
 lcd.clear(); 
 lcd.setCursor(0, 0); 
 lcd.print(" Invalid Key! "); 
 delay(1000); 
 lcd.clear(); 
 } 
  
 if(whichKey == password ) 
 { 
 setLocked (false); 
 lcd.clear(); 
 lcd.setCursor(0, 0);
 lcd.print(" Accepted "); 
 delay(1000); 
 lcd.clear(); 
 lcd.setCursor(0, 0); 
 lcd.clear(); 
 setLocked (true); 
 } 
 else  
 { 
 setLocked (true); 
 lcd.clear(); 
 lcd.setCursor(0, 0); 
 lcd.print(" Try again "); 
 delay(1000); 
 lcd.clear(); 
 lcd.setCursor(0, 0); 
 lcd.clear(); 
 } 
 delay(200); 
} 
void setLocked(int locked){ 
 if(locked){ 
 digitalWrite(redLED, HIGH); 
 digitalWrite(greenLED, LOW); 
 } 
 else{ 
 digitalWrite(redLED, LOW); 
 digitalWrite(greenLED, HIGH);
}}