Show 8051 interface with a 4x4 Matrix keyboard and seven-segment display and hence write a program to identify the key pressed. Assume Look Up table for Seven segment code is located at 0200H.

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written 6.5 years ago by

liviavaz • 230

modified 4.4 years ago by

ninadsail • 10

microcontroller and applications

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written 6.5 years ago by

liviavaz • 230

• modified 6.5 years ago

                MOV DPTR, #0200H
                MOV P2,   #0FFH
REPEAT:         MOV P1,   #00H                    
                MOV P1,   #0EH        
                MOV A,    P2         
                CJNE A,   #0FH, PRESSED
                SJMP      REPEAT

KEYPRESSED:     ACALL     DELAY  
                MOV R0,   #00H                                  ; Assume key "0" pressed 
                MOV P1,   #0EH                                  ; checking for row P1.0
                MOV A,    P2                                    ; Read the columns 
                CJNE A, …

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