PIC16Fxxx的LCD驅動(dòng)程序(適用于HD44780兼容的驅動(dòng)器)
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Call Delay_MS
;
movlw 0x02 ; Init for 4-bit interface
call Send_4bit
movlw .10 ; Delay 10 mS
Call Delay_MS
;
movlw b'00000011' ; Fully Initial LCD module
call Send_4bit ; Sent '0011' data 4 time
movlw .5 ; Delay 5mS
Call Delay_MS
movlw b'00000011'
call Send_4bit
call Delay_1MS ; Delay 1mS
movlw b'00000011'
call Send_4bit
movlw b'00000010'
call Send_4bit
;
movlw b'00101000' ; Set 2 lines 5 x 7 dots
call SendCmd
movlw DISP_ON ; Turn display on (0x0C)
call SendCmd
movlw ENTRY_INC ; Configure cursor movement
call SendCmd
movlw DD_RAM_ADDR ; Set writes for display memory
call SendCmd
return
;
;*******************************************************************
;*SendChar - Sends character to LCD *
;*This routine splits the character into the upper and lower *
;*nibbles and sends them to the LCD, upper nibble first. *
;*******************************************************************
putcLCD
banksel Byte
movwf Byte ; Save WREG in Byte variable
call Delay_1MS
swapf Byte,W ; Write upper nibble first
andlw 0x0f
movwf LCD_DATA
bsf LCD_CNTL, RS ; Set for data
bsf LCD_CNTL, E ; Clock nibble into LCD
bcf LCD_CNTL, E
movf Byte,W ; Write lower nibble last
andlw 0x0f
movwf LCD_DATA
bsf LCD_CNTL, RS ; Set for data
bsf LCD_CNTL, E ; Clock nibble into LCD
bcf LCD_CNTL, E
return
;
;*********************************************************************
;* To put the HEX value to LCD Display ,,
;* High nibble first than Low nibble
;* Input : W Reg.
;*********************************************************************
PutHexLCD
banksel W_BUFR
movwf W_BUFR ; Save W Register !!
swapf W_BUFR,W ; High nibble first !!
call Hex2ASCII
call putcLCD
;
movf W_BUFR,W
call Hex2ASCII
call putcLCD
return
;
;******************************************************************
;* Convert a low nibble to ASCII code
;* Input : W Reg.
;* Output: W Reg.
;******************************************************************
Hex2ASCII
andlw 0x0f ; Mask Bit 4 to 7
movwf Hex_Bfr
sublw .09
btfsc STATUS,C ; If W less than A (C=1) --> only add 30h
goto Add_W_30
Add_W_37 movlw 0x37
goto Hex_cont
Add_W_30 movlw 0x30
Hex_cont addwf Hex_Bfr,W ; The correct ASCII code for this char !!
return
;
;*******************************************************************
;* SendCmd - Sends command to LCD *
;* This routine splits the command into the upper and lower *
;* nibbles and sends them to the LCD, upper nibble first. *
;*******************************************************************
SendCmd
banksel Byte
movwf Byte ; Save WREG in Byte variable
call Delay_1MS
swapf Byte,W ; Send upper nibble first
andlw 0x0f
movwf LCD_DATA
bcf LCD_CNTL,RS ; Clear for command
bsf LCD_CNTL,E ; Clock nibble into LCD
bcf LCD_CNTL,E
movf Byte,W ; Write lower nibble last
Send_4bit andlw 0x0f
movwf LCD_DATA
bcf LCD_CNTL,RS ; Clear for command
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