Interfacing Keypad with 8051 Microcontroller using Keil C
Matrix Keypad Matrix Keypads are commonly used in calculators, telephones etc where a number of input switches are required. We know that matrix keypad is made by arranging push button switches in row and columns. In the straight forward way to connect a 4x4 keypad (16 switches) to a microcontroller we need 16 inputs pins. But by connecting switches in the following way we can read the status of each switch using 8 pins of the microcontroller. 4x4-Matrix-Keypad The status of each keys...