This project demonstrates how to interface a 4x4 matrix keypad with the ATmega2560 microcontroller using direct port manipulation in C (bare-metal programming). It includes keypad scanning logic and ...

A 4x4 matrix keypad consists of 16 push buttons arranged in 4 rows and 4 columns: Each row has one terminal of 4 buttons connected Each column represents the other terminals of buttons in that column ...

Using eight digital inputs, this circuit simplifies decoding of the common membrane 4x4 keypad matrix and eliminates the traditional requirement of scanning rows or columns. Any X-Y switch matrix, ...