4x4 Keypad Matrix

A 4×4 keypad matrix is an input device made up of 16 push buttons arranged in 4 rows and 4 columns. Instead of connecting each button individually, the keys are wired in a grid pattern, allowing a microcontroller to detect which key is pressed by scanning rows and columns. When a button is pressed, it connects a specific row and column, enabling efficient input detection using fewer pins. This design is commonly used in embedded systems, such as calculators, security systems, and DIY electronics projects, because it is simple, cost-effective, and easy to interface with microcontrollers.