电子时钟（51单片机定时器，1602液晶）

#include<reg52.h>
#include<stdlib.h>
#include<stdio.h>
#include<intrins.h>
#define uint unsigned int
#define uchar unsigned char

uint num,A_num,x=0;
uint h,m,s,year=2012,month=1,day=22,lcd_x=0,lcd_y=0;

uchar code Zifu[]="0123456789";

sbit beep = P2^3;

sbit LCD_EN = P3^4;
sbit LCD_RS = P3^5;

sbit duan = P2^6;
sbit wei = P2^7;

sbit key_A = P3^6;
sbit key_B = P3^7;

void delay_1ms(uchar x){
uchar i,j;
for(j=0;j<x;j++)
for(i=0;i<110;i++);
}

void write_command(uchar command){
LCD_RS = 0;
LCD_EN = 0;
P0 = command;
delay_1ms(2);
LCD_EN = 1;	 		//EN 由1 -- 0 完成 有效数据 的 锁存
delay_1ms(2);
LCD_EN = 0;
}

void write_data(uchar fuck){
LCD_RS = 1;
LCD_EN = 0;
P0 = fuck;
delay_1ms(2);
LCD_EN = 1;
delay_1ms(2);
LCD_EN = 0;
}

void lcd_post(int X,int Y){			//0,1表征 第一行 和 第二行
write_command(0x80+X*(0x40)+Y);
}

void init(){
h=m=s=0;
num=A_num=0;

LCD_EN=0;
write_command(0x38);
write_command(0x0c);
//write_command(0x06); //写字符后地址指针加一
write_command(0x01);

TMOD = 0x02;
TH0 = 6;
TL0 = 6;
EA = 1;
ET0 = 1;
TR0 = 1;

/*时分秒*/
lcd_post(0,0); write_data(Zifu[h/10]);
lcd_post(0,1); write_data(Zifu[h%10]);

lcd_post(0,2); write_data(':');

lcd_post(0,3); write_data(Zifu[m/10]);
lcd_post(0,4); write_data(Zifu[m%10]);

lcd_post(0,5); write_data(':');

lcd_post(0,6); write_data(Zifu[s/10]);
lcd_post(0,7); write_data(Zifu[s%10]);

/*年月日*/
lcd_post(1,6); write_data(Zifu[year/1000]);
lcd_post(1,7); write_data(Zifu[(year%1000)/100]);
lcd_post(1,8); write_data(Zifu[(year%100)/10]);
lcd_post(1,9); write_data(Zifu[year%10]);

lcd_post(1,10); write_data('-');

lcd_post(1,11); write_data(Zifu[month/10]);
lcd_post(1,12); write_data(Zifu[month%10]);

lcd_post(1,13); write_data('-');

lcd_post(1,14); write_data(Zifu[day/10]);
lcd_post(1,15); write_data(Zifu[day%10]);
}

void di(){
beep=0; delay_1ms(100); beep=1;
}

void keyscan(){
if(key_A==0){
delay_1ms(3);
if(key_A==0){
A_num++;
di();
switch(A_num){
case 1:							  //时
TR0=0;
lcd_post(0,1);
write_command(0x0f);
break;
case 2:lcd_post(0,4);break;		  //分
case 3:lcd_post(0,7);break;		  //秒

case 4:lcd_post(1,6);break;		  //年
case 5:lcd_post(1,7);break;
case 6:lcd_post(1,8);break;
case 7:lcd_post(1,9);break;

case 8:lcd_post(1,12);break;		  //月
case 9:lcd_post(1,15);break;		  //日
case 10:
A_num=0;
write_command(0x0c);
TR0=1;
break;
}
}
while(!key_A);
}
if(A_num!=0){
if(key_B==0){
delay_1ms(3);
if(key_B==0){
di();

switch(A_num){
case 1:
h=(++h)%24;
lcd_post(0,0); write_data(Zifu[h/10]);
lcd_post(0,1); write_data(Zifu[h%10]);
break;		  //时
case 2:
m=(++m)%60;
lcd_post(0,3); write_data(Zifu[m/10]);
lcd_post(0,4); write_data(Zifu[m%10]);
break;		  //分
case 3:
s=(++s)%60;
lcd_post(0,6); write_data(Zifu[s/10]);
lcd_post(0,7); write_data(Zifu[s%10]);
break;		  //秒

case 4:			  //年
lcd_post(1,6);
write_data(Zifu[(++x)%10]);
break;
case 5:
lcd_post(1,7);
write_data(Zifu[(++x)%10]);
break;
case 6:
lcd_post(1,8);
write_data(Zifu[(++x)%10]);
break;
case 7:
lcd_post(1,9);
write_data(Zifu[(++x)%10]);
break;

case 8:
month=(++month)%13;
lcd_post(1,11); write_data(Zifu[month/10]);
lcd_post(1,12); write_data(Zifu[month%10]);
break;		  //月
case 9:
day=(++day)%32;
lcd_post(1,14); write_data(Zifu[day/10]);
lcd_post(1,15); write_data(Zifu[day%10]);
break;		  //日
case 10:break;
}write_command(0x10);
}
while(!key_B);
}
}
}

void main()
{
init();
while(1){
if(num==3686){
num=0;
s++;
if(s==60){
s=0;
m++;
if(m==60){
m=0;
h++;
if(h==24)h=0;
lcd_post(0,0); write_data(Zifu[h/10]);
lcd_post(0,1); write_data(Zifu[h%10]);
}
lcd_post(0,3); write_data(Zifu[m/10]);
lcd_post(0,4); write_data(Zifu[m%10]);
}
lcd_post(0,6); write_data(Zifu[s/10]);
lcd_post(0,7); write_data(Zifu[s%10]);
}
keyscan();

}
}

void T0_time() interrupt 1
{
num++;
}