printf函数在lcd1602上的实现.doc

利用printf（）函数在51系统中显示到lcd上将.KeilC51LIB目录下的PUTCHAR.C文件copy到自己的工程文件下，并修改：PUTCHAR.C/*/* This file is part of the C51 Compiler package */* Copyright KEIL ELEKTRONIK GmbH 1990 - 2002 */*/* */* PUTCHAR.C: This routine is the general character output of C51. */* You may add this file to a uVision2 project. */* */* To translate this file use C51 with the following invocation: */* C51 PUTCHAR.C */* */* To link the modified PUTCHAR.OBJ file to your application use the */* following Lx51 invocation: */* Lx51 , PUTCHAR.OBJ */* */*/#include #define XON 0x11#define XOFF 0x13/* * putchar (full version): expands n into CR LF and handles * XON/XOFF (Ctrl+S/Ctrl+Q) protocol */char putchar (char c) if (c = n) if (RI) if (SBUF = XOFF) do RI = 0; while (!RI); while (SBUF != XON); RI = 0; while (!TI); TI = 0; SBUF = 0x0d; /* output CR */ if (RI) if (SBUF = XOFF) do RI = 0; while (!RI); while (SBUF != XON); RI = 0; while (!TI); TI = 0; return (SBUF = c);#if 0 / comment out versions below/* * putchar (basic version): expands n into CR LF */char putchar (char c) if (c = n) while (!TI); TI = 0; SBUF = 0x0d; /* output CR */ while (!TI); TI = 0; return (SBUF = c);/* * putchar (mini version): outputs charcter only */char putchar (char c) while (!TI); TI = 0; return (SBUF = c);#endif/*/MAIN.C/#include #include void main()int i;i=100;init_lcd1602();printf(hello!nyour goald:%d,i);while(1);/LCD1602.H/*-LCD1602.HHeader file for LCD_NS1602A.Programer:bai-*/#ifndef _LCD1602_H_#define _LCD1602_H_#include char putchar (char c);void init_lcd1602();#endif/LCD1602.C/* *This is a program for LCD_NS1602Abase on 89C52rc */#include reg52.H#include bit lcd_flag=0;sbit LCD1602_RS=P24;/*definition of RS*/sbit LCD1602_RW=P25;/*definition of RW*/sbit LCD1602_EN=P26;/*definition of E*/* * * * */void lcd_delay()int i;for(i=0;i2;i+)_nop_();void com_w(int com)lcd_delay(); LCD1602_RS = 0;/*RS=0 : command */ LCD1602_RW = 0; /*RW=0 : write*/ LCD1602_EN = 0; LCD1602_EN = 1; P0 = com; LCD1602_EN = 0;void dat_w(int dat)lcd_delay(); LCD1602_RS = 1;/*RS=0 : command */ LCD1602_RW = 0; /*RW=0 : write*/ LCD1602_EN = 0; LCD1602_EN = 1; P0 = dat; LCD1602_EN = 0;void init_lcd1602()com_w(0x01);/*clear screen */com_w(0x02);/*clear screen */com_w(0x38);/*8位接口，双行，5*10点阵*/com_w(0x06);/*reset Address Co