;============================={INFORMATION}================================== ; File: lcd.asm ; Project: PIC/lcd ; Author: Tamás Nagy ; Version: 1.00 ; Used PIC: PIC16F88A ;**************************************************************************** ;============================={DESCRIPTION}================================== ;**************************************************************************** ;==========================={SPECIFICATIONS}================================= ;**************************************************************************** ;==================={PROCESSOR + INCLUDE + CONFIG}=========================== #include ;**************************************************************************** ;=============================={DEFINITIONS}================================= ;-------------------------------{I/O PORTS}---------------------------------- #define LCD_E LATB,1 #define LCD_RS LATB,0 #define LCD_D4 LATB,2 #define LCD_D5 LATB,3 #define LCD_D6 LATB,4 #define LCD_D7 LATB,5 #define w 0 #define f 1 ;-------------------------------{CONSTANTS}---------------------------------- ;-------------------------------{VARIABLES}---------------------------------- cblock 0x060 t,t1,t2,LCD_Temp,temp endc ;--------------------------------{MACROES}----------------------------------- ;**************************************************************************** ;=============================(PROGRAM START)================================ org 0x00 ;**************************************************************************** ;//////////////////////////////////{MAIN}\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\ ;--------------------------{MAIN INITIALIZATIONS}---------------------------- main: movlw 0x50 movwf OSCCON clrf ANCON1 clrf ADCON0 clrf PORTB clrf LATB clrf TRISB call LCD_Init ;**************************************************************************** ;==========================={MAIN PROGRAM START}============================= loop: bcf LCD_RS movlw b'00001111' call LCD_Data movlw 0x8A call LCD_Data movlw b'00001110' call LCD_Data bsf LCD_RS movlw 'E' call LCD_Data movlw 'z call LCD_Data movlw ' ' call LCD_Data movlw 'm' call LCD_Data movlw 'u' call LCD_Data movlw 'k' call LCD_Data movlw 'o' call LCD_Data movlw 'd' call LCD_Data movlw 'i' call LCD_Data movlw 'k' call LCD_Data sleep ;============================={INFORMATION}================================== ; File: lcd.asm ; Project: PIC/lcd ; Author: Tamás Nagy ; Version: 1.00 ; Used PIC: PIC16F88A ;**************************************************************************** ;============================={DESCRIPTION}================================== ;LCD functions> ; LCD_Init - initalize LCD display ; LCD_Data - send data to LCD ; LCD_Instr - send instruction to LCD ; LCD_Clear - clear LCD ; LCD_Goto - move cursor to position ; LCD_ON - LCD ON ; LCD_OFF - LCD OFF ; LCD_Shift_Left - shift display left ; LCD_Shift_Right - shift diplay right ; LCD_Cursor_ON - cursor ON ; LCD_CBlink_ON - cursor and cursor blink ON ; LCD_CB_OFF - cursor and cursor blink OFF ; LCD_Cursor_Inc - increment cursor position after writing data ; LCD_Cursor_Dec - decrement cursor position after writing data ; LCD_Home - return home (position 0) ;**************************************************************************** ; Delay times> ; delay_100ms: ; 16MHz = 50ms ; 8MHz = 100ms -> default setting, must change the delay ; 4MHz = 200ms ; 1MHz = 400ms ; delay_1ms: ; 16MHz = 500us ; 8MHz = 1ms -> default setting, must change the delay ; 4MHz = 2ms ; 1MHz = 4ms ;**************************************************************************** ;------------------------------{DEFINITIONS}--------------------------------- ;-------------------------------{VARIABLES}---------------------------------- ; cblock 0x20 ; t,t1,t2,LCD_Temp,temp,count ; endc ;=================================={LCD}===================================== LCD_Init: bcf LCD_RS movlw d'50' ;wait more than 15ms power time call delay_1ms movlw b'00110000' ;function set, interface is 8 bit long call LCD_Data movlw d'20' ;wait more than 5ms call delay_1ms movlw b'00110000' ;function set, interface is 8 bit long call LCD_Data movlw d'7' ;wait more than 100us call delay_1ms movlw b'00110000' ;function set, interface is 8 bit long call LCD_Data movlw d'2' ;wait call delay_1ms movlw b'00100000' ;function set, interface is 4 bit long call LCD_Data movlw d'2' ;wait call delay_1ms movlw b'00101000' ;0 0 1 DL N F - - call LCD_Data ;DL=0 (4 bit comunication), N=1 (two lines), F=0 (font= 5x8 dots) movlw d'2' ;wait call delay_1ms movlw b'00001000' ;0 0 0 0 1 D C B call LCD_Data ;D=0 (display off), C=0 (cursor off), B=0 (cursor blinking off) movlw d'2' ;wait call delay_1ms movlw b'00000001' ;clear display call LCD_Data movlw d'15' ;wait call delay_1ms movlw b'00000110' ;0 0 0 0 0 1 I/D S call LCD_Data ;I/D=1 (increment position), S=1 (display shift) movlw d'2' ;wait call delay_1ms movlw b'00001111' ;turn on display, cursor and blinking call LCD_Data movlw d'2' ;wait call delay_1ms movlw 0x02 call LCD_Data bsf LCD_RS return ;-----------------------------{Send LCD data}-------------------------------- LCD_Data: movwf LCD_Temp bcf LCD_D7 ;clear all data pins bcf LCD_D6 bcf LCD_D5 bcf LCD_D4 btfsc LCD_Temp,7 ;writing upper 4 bits bsf LCD_D7 btfsc LCD_Temp,6 bsf LCD_D6 btfsc LCD_Temp,5 bsf LCD_D5 btfsc LCD_Temp,4 bsf LCD_D4 bsf LCD_E movlw d'1' call delay_1ms bcf LCD_E bcf LCD_D7 ;clear again all data pins bcf LCD_D6 bcf LCD_D5 bcf LCD_D4 btfsc LCD_Temp,3 ;write lower 4 bits bsf LCD_D7 btfsc LCD_Temp,2 bsf LCD_D6 btfsc LCD_Temp,1 bsf LCD_D5 btfsc LCD_Temp,0 bsf LCD_D4 bsf LCD_E movlw d'1' call delay_1ms bcf LCD_E return ;--------------------------{Send LCD instruction}---------------------------- ;--------------------------------{LCD Clear}--------------------------------- ;**************************************************************************** ;-------------------------------{DELAY 100ms}-------------------------------- delay_100ms: ;default 8MHz clock movwf t clrf t1 ;16MHz = 50ms clrf t2 ;8MHz = 100ms del: decfsz t2,f ;4MHz = 200ms goto del ;1MHz = 400ms decfsz t1,f goto del decfsz t,f goto del return ;--------------------------------{DELAY 1ms}---------------------------------- delay_1ms: ;default 8MHz clock movwf t clrf t1 ;16MHz = 500us del1: nop ;8MHz = 1ms nop nop nop nop nop decfsz t1,f ;4MHz = 2ms goto del1 ;1MHz = 4ms decfsz t,f goto del1 return ;**************************************************************************** end