In this tutorial we are going to learn some basics on using Keypad 4×4 on Arduino.
This keypad consists of 4 rows x 4 columns of buttons. It is ultra-thin that it provides an useful human interface component for microcontroller projects. Convenient adhesive backing provides a simple way to mount the keypad in a variety of applications, such as menu selection, security systems, data entry for embedded systems and so on.
How to interface Keypad 4×4 with Arduino – [Link]