The 4×4 keypad is a composite of 16 keys arranged like a matrix. The method used for accessing 4×4 keypad with matrix scanning method. The 4×4 keypad requires 8 pins to access it, ie 4 pins for the columns and 4 pins for the line. How the scanning method works is that the column pin takes the LOW lo…By: sfeelectronics // Read more: original article.
