and if you only want the keypad functionality it's recommended, but we still need to connect the RC522 and the Display, so we'll need those pins later, we are going to "free" pins by turning the ...

In Embedded system design, matrix keypad (4x4, 4x3, 3x3 or 5x5) is used for key in the user inputs. Similarly character LCD display [16x2, 16x4, 20x2 or 20x4 LCDs] is used for indicating the system ...