Many common and popular devices can be found that use numeric keypads - from the telephone, to ATM, microwave oven, calculator and more. However if you've been wanting to use one as a form of user-interface with an Arduino, doing so may have seemed complex - until now. Thanks to the tronixstuff website numeric keypads are no longer a mystery, and after following their tutorials you'll be able to use 12 and 16 button keypads in no time.
Apart from explaining the required hardware connections, using the Arduino library and offering simple demonstrations, the tutoiral also includes an example project of a bare PIN-activated switch, perfect for adding a level of security to any Arduino-based project which is demonstrated in the following video:
If you're using an LCD with your Arduino-based projects - instead of building your own LCD module onto a breadboard, save time and move forward with the Freetronics LCD & Keypad shield which contains a bright 16x2 character LCD and five buttons that can be read from only one analog input pin: