Interfacing 4x4 Matrix Keypad | AT89C51
I am using the AT89C51 to interface the 4x4 Matrix Keypad and display the Input on a 16x2 LCD Display. The tools I will be using are : Keil uVision 5 Proteus 8 Professional The LCD is operated in 8 bit mode to display the key that is pressed. The keypad is connected to Port-1 and the LCD is connected to Port-2 [Data Pins : D0-D7]. Initially the keypad is connected such that Row pins are LOW [ 0 ] and Column pins are HIGH [ 1 ]. Whenever a key is pressed, it will short the circuit and gives the Column a LOW. Then a function is called to check which ROW that key belongs to. For this purpose, we use four user defined functions to determine the ROW number. NOTE : Here the key should be pressed down for 2 seconds to display the input on the screen. This can be debugged along the way. _______________________________________________________________________________ Code : Embedded C IDE : Keil uVision 5 Simulator : Proteus 8 Professional uController : AT89C51 /* Created by mbe...