NEW! |
; (This code is not mine, except for the delays, I just added this comments) ; ;Connection is like this: ; ; PIC LCD ; ------------- ; RBO E ; RB1 RS ; RB2 RW ; RB3 -- ; RB4 D4 ; RB5 D5 ; RB6 D6 ; RB7 D7 ; ; (RB0-RB7: PIC PINS 6-13 RESPECTIVELY) ; (E, RS, RW, D4-D7: LCD PINS 6, 4, 7, 10-14 RESPECTIVELY) ; ; MAKE SURE YOU CONNECT THE CONTRAST POT (10K) TO PIN 3 ; POWER IS 1: GND, 2: +5V ; ; ; the subroutine DELAY seems to be the same as DELAY_MS, at least it works if you change all 'delay' to 'delay_ms' ; here's the Q&D delay I use (1ms for 4MHz XT): ; ; ; delays cblock 0x0D d1 d2 bit_tmp msres endc delay_ms movwf msres dl3 decfsz msres, f goto dl return dl ;993 cycles movlw 0xC6 movwf d1 movlw 0x01 movwf d2 delay_ms_0 decfsz d1, f goto $+2 decfsz d2, f goto delay_ms_0 ;3 cycles nop goto dl3 ;lcd routines cblock 0x2A lcd_shadow,lcd_tmp,lcda,lcd_char endc #define lcd_port PORTB #define lcd_enable lcd_shadow,0 #define lcd_rs lcd_shadow,1 #define lcd_rw lcd_shadow,2 ;------------------------------ lcd_uport macro movf lcd_shadow,w movwf lcd_port endm ;------------------------------ ;strobe lcd enable lcd_strobe: movlw .20 call delay bsf lcd_enable lcd_uport movlw .20 call delay movf lcd_port,w andlw 0xF0 movwf lcd_tmp bcf lcd_enable lcd_uport swapf lcd_tmp,w return ;------------------------------ lcd_send_nibble: movwf lcd_tmp movlw 0x0F andwf lcd_tmp,f andwf lcd_shadow,f swapf lcd_tmp,w iorwf lcd_shadow,f lcd_uport goto lcd_strobe ;------------------------------ lcd_read_byte: movlw 0xF0 tris lcd_port bsf lcd_rw lcd_uport call lcd_strobe movwf lcda swapf lcda,f call lcd_strobe iorwf lcda,f movlw 0 tris lcd_port bcf lcd_rw movf lcda,w return ;------------------------------ #define sv_addr bit_tmp,0 lcd_putc: bsf lcd_rs lcd_send_byte: movwf lcd_char bcf sv_addr btfsc lcd_rs bsf sv_addr bcf lcd_rs sb0 call lcd_read_byte ;wait until not lcd busy andlw B'10000000' skpz goto sb0 bcf lcd_rw bcf lcd_rs btfsc sv_addr bsf lcd_rs swapf lcd_char,w call lcd_send_nibble movf lcd_char,w goto lcd_send_nibble ;------------------------------ lcd_init: movlw 0 tris lcd_port clrf lcd_shadow lcd_uport movlw .50 call delay_ms movlw 3 movwf lcda bcf lcd_rs lcdi0 movlw 3 call lcd_send_nibble movlw .15 call delay_ms decfsz lcda,f goto lcdi0 movlw .2 call lcd_send_nibble movlw B'00101000' ;function set call lcd_send_byte ;4 bit,1/6 duty,5x8 movlw B'00001000' ;display off,cursor off, blink off call lcd_send_byte movlw B'00000001' ;clear screen cursor home call lcd_send_byte movlw B'00000110' ;Increment cursor, don't shift screen call lcd_send_byte movlw B'00001111' ;display on,cursor on, blink on call lcd_send_byte return ;------------------------------ ;lcd_gotoxy ; input W = YYXXXXXX ; 76543210 ; ; Y address ; --- ------- ; 00 0 ; 01 0x40 ; 10 20 ; 11 0x40+20 xy_loc macro x, y movlw (y << 6) | (x & B'00111111') call lcd_gotoxy endm lcd_gotoxy: movwf lcd_tmp andlw B'00111111' btfsc lcd_tmp,6 addlw 0x40 btfsc lcd_tmp,7 addlw .20 iorlw B'10000000' bcf lcd_rs goto lcd_send_byte ;------------------------------ lcd_cursor_off: bcf lcd_rs movlw B'00001100' ;display on,cursor off, blink off goto lcd_send_byte ;------------------------------ lcd_cursor_on: bcf lcd_rs movlw B'00001111' ;display on,cursor on, blink on goto lcd_send_byte
file: /Techref/microchip/4bitlcd.htm, 4KB, , updated: 2009/10/1 10:39, local time: 2024/10/8 11:57,
35.170.81.33:LOG IN ©2024 PLEASE DON'T RIP! THIS SITE CLOSES OCT 28, 2024 SO LONG AND THANKS FOR ALL THE FISH!
|
©2024 These pages are served without commercial sponsorship. (No popup ads, etc...).Bandwidth abuse increases hosting cost forcing sponsorship or shutdown. This server aggressively defends against automated copying for any reason including offline viewing, duplication, etc... Please respect this requirement and DO NOT RIP THIS SITE. Questions? <A HREF="http://www.sxlist.com/Techref/microchip/4bitlcd.htm"> PIC 4 bit 16x2 Hitachi LCD driver</A> |
Did you find what you needed? |
Welcome to sxlist.com!sales, advertizing, & kind contributors just like you! Please don't rip/copy (here's why Copies of the site on CD are available at minimal cost. |
Welcome to www.sxlist.com! |
.