For this, just wire up the hardware (arduino+keypad) as described earlier. Although the code is an entry-level one, it includes a secret key option that will need to be entered on the keypad.

[Andrea] just sent us this great student hack he made for his room. He’s constructed an Arduino keypad door lock — without using any proper fastening hardware! The entire build is made out of ...

Watch the video below to learn more about his Arduino-based portable keypad that connects to your Arduino development board and offers the complete alphabet, numbers 0-9 as well as several commands.