Embedded System Project : Keypad Lock

Make a keypad lock with use of embedded system is easiest project for students. Keypad lock is the device which is provide security with password. It is a security device. This embedded system is useful in door lock, locker, and on other device which is protected by password.


Used elements for this project :-

1 Arduino board

4×4 or 3×4 Keypad


Here, This embedded software has total  8 cables which are connected to the Arduino board’s digital pins. Where 4 pins are supply the power in row and other 4 pins are supply in columns.

Note :- If you are doing this project by reference from our site than note it, you need to enter password from keypad not in serial monitor.

Embedded System Keypad Lock

Source Code

					#include <Keypad.h>

const int ROW_NUM = 4;
const int COLUMN_NUM = 4;

const String password = "8080";
String input_password;

char keys[ROW_NUM][COLUMN_NUM] =
   {'1','2','3', 'A'},
   {'4','5','6', 'B'},
   {'7','8','9', 'C'},
   {'*','0','#', 'D'}

byte pin_rows[ROW_NUM] = {9, 8, 7, 6};
byte pin_column[COLUMN_NUM] = {5, 4, 3, 2};

Keypad keypad = Keypad( makeKeymap(keys), pin_rows, pin_column, ROW_NUM, COLUMN_NUM );

void setup()

void loop()
   char key = keypad.getKey();

   if (key)

        if(key == '*')
            input_password = "";

        else if(key == '#')
            if(password == input_password)
                Serial.println("password is correct");

                Serial.println("password is incorrect, try again");

            input_password = "";

            input_password += key;


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