In many embedded projects you need some input device like keypad. You don’t need to mess around by making your own keypad – it is better to use one that looks nice and is reliable. So following project simply interfaces a standard 12 button keypad to Arduino.
By using Arduino you even don’t have to write a lot of code as there are libraries available that allows to interact with keypad. By following this tutorial you’ll learn how to read keypad with Arduino and prompt for password via serial terminal.