JHD162A-LCD_4BitDriver-v1

[VEDANG_JADHAV]

EN EQU P0.3
RW EQU P0.2
RS EQU P0.1

ORG    0000H
CLR    RW
SETB RW
CLR    RW
CLR    RS
SETB RS
CLR    RS
CLR    EN
SETB EN
CLR    EN
MOV DPTR,#INITIALIZE_CONFIG_4bit
LCALL WRITE_COMMAND
MAIN_PROGRAM:
MOV DPTR,#DISPLAYDATA
LCALL WRITE_DATA
MOV    DPTR,#CURSOR_POSITION
LCALL WRITE_COMMAND
LJMP MAIN_PROGRAM

WRITE_DATA:
SETB RS
LCALL ACCESS_DATA
MOV DPTR,#CLEAR_CODE
LCALL WRITE_COMMAND
RET
 
WRITE_COMMAND:
CLR RS
LCALL ACCESS_DATA
RET

ACCESS_DATA:
CLR    A
MOVC A,@A+DPTR
CJNE A,#0FFH,SKIPRESET
LCALL DELAY2
RET
SKIPRESET:
LCALL WRITE_TEXT
INC    DPTR
LJMP ACCESS_DATA

WRITE_TEXT:        ;4BIT NIBBLE LATCHING [twice]
MOV    R7,A
LCALL HIGH4BITS
LCALL LATCH_DATA
LCALL DELAY1
MOV    A,R7
LCALL LOW4BITS
LCALL LATCH_DATA
LCALL DELAY1
CLR    A
RET

LATCH_DATA:
SETB EN
CLR EN
RET    
    
LOW4BITS:         ;BIT BANG LSB
MOV C,ACC.3
MOV P0.7,C
MOV C,ACC.2
MOV P0.6,C
MOV C,ACC.1
MOV P0.5,C
MOV C,ACC.0
MOV P0.4,C
RET

HIGH4BITS:        ;BIT BANG MSB
MOV C,ACC.7
MOV P0.7,C
MOV C,ACC.6
MOV P0.6,C
MOV C,ACC.5
MOV P0.5,C
MOV C,ACC.4
MOV P0.4,C
RET

DELAY1:
MOV R3,#01H
Divisioned_loop1:
Mov R4 , #15H
Mini_wait1:
djnz r4,Mini_wait1
djnz r3,Divisioned_loop1
RET

DELAY2:
MOV R3,#010H
Divisioned_loop2:
Mov R4 , #0FFH
Mini_wait2:
djnz r4,Mini_wait2
djnz r3,Divisioned_loop2
RET

LCD_POWERLOAD_DELAY:
MOV R3,#0FFH
Divisioned_loop3:
Mov R4 , #0FFH
Mini_wait3:
djnz r4,Mini_wait3
djnz r3,Divisioned_loop3
RET

INITIALIZE_CONFIG_4bit:
DB 028H,0CH,06H
DB 0FFH

INITIALIZE_CONFIG_8bit:
DB 038H,0CH,06H
DB 0FFH

CLEAR_CODE:
DB 01H
DB 0FFH

shift_disp_right_code:
DB 04H
DB 0FFH

shift_disp_left_code:
DB 07H
DB 0FFH

CURSOR_POSITION:
DB 080H
DB 0FFH

DISPLAYDATA:
DB ‘BLUETOOTH SCAN #’
DB 0FFH

END

[Author]

Posts