Electronic and Arduino enthusiasts searching for an Arduino ... It is also faster to use than typing the code of the keypad door lock. Just place the finger and open the door.

He used an Arduino, and multiplexed RGB LEDs ... you can use a LED and a resistor to indicate the door lock state for testing your code. The keypad is actually built from two separate circuits ...

If you want to add a keypad to your Arduino project, the options are pretty limited. There’s that red and blue 4×4 membrane we’ve all seen in password-protected door lock projects ...

connect to the column C1-C3 pinouts of the keypad Next is a project example, where the Arduino is instructed to do something based on a correct key (secret number) being entered into the keypad, ...