This project is using arduino board for security lock using keypad. This project can be used in security applications. The project is using two 270 ohm resistors and two LED's . Advantage is that you can set your own custom password for unlocking.
Circuit Diagram
Working
When you press a key on the keypad the corresponding 7 bit signal of that key is sent to arduino pins D1 to D7. Output is connected to D8 and D9 pins of Arduino board. Output is indicated by two LED's. When the entered password is correct Green LED will be ON and Red LED will be off. Similarly when Password is incorrect Red LED glows and Green LED is OFF.
Component List
| Component | Value | Quantity |
| Resistor | 270 Ohms | 2 |
| LED | Red 5mm | 1 |
| LED | Green 5mm | 1 |
| Arduino | Diecimila or Duemilanove board | 1 |
Code