[Travis] and [Fabienne] went a different route, and are emulating the keypad using an Arduino and a set of transistors. They started by reverse engineering the keypad matrix using a continuity tester.

This proposed Arduino-based automatic bell device is an electronic system that rings bells at predefined times without manual ...

However, with [jakeofalltrades’] project, you can read an old-fashioned phone dial using an Arduino. The idea behind ... Or, why not a numeric keypad?