51单片机实现数字时钟

用单片机实现数字时钟,关于时间显示,是用的1602液晶,C51单片机,然后再加一个定时器,每到一秒就动态的更新一下液晶的时间显示,在更新的时候也要计算相应的分针和时针的变化,还要注意边界问题.为了能够达到一个最好的效果,我还加了一个键盘扫描,用到了3个键,分别为功能键,增1,减1来实现用户自定义时间. 在实现过程中,用到了单片机的中断系统的相关知识,还有定时器,液晶显示,键盘的动态扫描,都是以前的知识,没什么难度.

程序如下,可以正常运行. C代码

＃i nclude #define uint unsigned int #define uchar unsigned char

sbit lcdrs = P1^0; sbit lcdrw = P1^1; sbit lcden = P1^2;

sbit key0 = P2^0;//功能键,选择时分秒 sbit key1 = P2^1;//加1键 sbit key2 = P2^2;//减1键 sbit key4 = P2^4;

uchar key0_count;//按键0被按的次数(0~3)

char hour,minute,second; //时分秒 uint timer_count; //定时器中断计数

uchar table_date[] = \"2009-4-12 Mon\"; uchar table_time[] = \"00:00:00\";

/****** 函数申明 ********/ void write_cmd_1602(uchar cmd); void write_data_1602(uchar dat); void write_add(uchar add,uchar dat); void init1602(); void delay(uint z); uchar reverse(uchar c); void keyscan(); void init();

/****** 主函数 ********/ void main() { init(); //init1602();

//while(1); while(1) {

keyscan(); delay(5); } }

//1602液晶初始化 void init1602() {

lcdrw = 0; //本程序只读不写,故将其置低 lcden = 0; //关闭1602 delay(5);

write_cmd_1602(0x01); //清屏 write_cmd_1602(0x38); //显示模式

write_cmd_1602(0x0c); //开显示,不显示光标,不闪烁 write_cmd_1602(0x06); //地址指针自动加1

write_cmd_1602(0x80+1);//将光标指向第一行第二个位置 delay(5); }

void delay(uint z) {

uint x,y;

for(x=z;x>0;x--) for(y=110;y>0;y--); }

/** 将发送的数据进行翻转,高位到低位,低位转到高位 **/ uchar reverse(uchar c) {

uchar chbuff=0;

if (c&0x01) chbuff=chbuff|0x80; if (c&0x02) chbuff=chbuff|0x40; if (c&0x04) chbuff=chbuff|0x20; if (c&0x08) chbuff=chbuff|0x10; if (c&0x10) chbuff=chbuff|0x08; if (c&0x20) chbuff=chbuff|0x04; if (c&0x40) chbuff=chbuff|0x02; if (c&0x80) chbuff=chbuff|0x01; return chbuff; }

//向液晶写命令

void write_cmd_1602(uchar cmd) {

lcdrs = 0; //低表示写命令,高表示写数据

delay(5);

P0 = reverse(cmd); delay(5);

lcden = 1; //给一个高脉冲 delay(5); lcden = 0; delay(5); }

//向液晶写数据

void write_data_1602(uchar dat) {

lcdrs = 1; //低表示写命令,高表示写数据 delay(5);

P0 = reverse(dat); delay(5);

lcden = 1; //给一个高脉冲 delay(5); lcden = 0; delay(5); }

//根据地址向液晶写数据

void write_add(uchar add,uchar dat) {

uchar shi,ge; shi = dat/10; ge = dat%10; delay(5);

write_cmd_1602(0x80+add); write_data_1602(shi+0x30); delay(5);

write_data_1602(ge+0x30); }

//键盘扫描函数 void keyscan() {

key4 = 0;

if(0==key0) //第一个键被按下 {

delay(5); //消抖 if(0==key0) {

key0_count ++; if(4==key0_count) key0_count = 0;

while(!key0); //松手检测 if(0==key0_count) {

TR0 = 1; //重新开始计时

write_cmd_1602(0x0c); //禁止显示光标并不让其闪烁 }

if(1==key0_count) {

TR0 = 0; //暂停计时

write_cmd_1602(0x80+0x40+11);//将地址指针指向秒的位置 write_cmd_1602(0x0f); //显示光标并闪烁 delay(5); }

if(2==key0_count) {

TR0 = 0; //暂停计时

write_cmd_1602(0x80+0x40+8);//将地址指针指向分的位置 write_cmd_1602(0x0f); //显示光标并闪烁 delay(5); }

if(3==key0_count) {

TR0 = 0; //暂停计时

write_cmd_1602(0x80+0x40+5);//将地址指针指向小时的位置 write_cmd_1602(0x0f); //显示光标并闪烁 delay(5); } } }

if(0==key1) //第二个键被按下 {

delay(5); //消抖 if(0==key1) {

while(!key1); //松手检测 if(key0_count==1) {

second ++; if(60==second) second = 0;

write_add(0x40+10,second); }

if(key0_count==2) {

minute ++; if(60==minute) minute = 0;

write_add(0x40+7,minute); }

if(key0_count==3) {

hour ++; if(24==hour) hour = 0;

write_add(0x40+4,hour); } } }

if(0==key2) //第三个键被按下 {

delay(5); //消抖 if(0==key2) {

while(!key2); //松手检测 if(key0_count==1) {

second --; if(-1==second) second = 59;

write_add(0x40+10,second); }

if(key0_count==2) {

minute --; if(-1==minute) minute = 59;

write_add(0x40+7,minute); }

if(key0_count==3) {

hour --; if(-1==hour) hour = 23;

write_add(0x40+4,hour); } } }

}

//程序初始化函数 void init() {

uchar i; hour = 0; minute = 0; second = 0; key0_count = 0; init1602();

delay(20); //延长时间,确保液晶处于非忙状态 for(i=0;i<14;i++) {

write_data_1602(table_date[i]); delay(5); }

write_cmd_1602(0x80+0x40+4); //调整地址指针 for(i=0;i<8;i++) {

write_data_1602(table_time[i]); delay(5); }

//初始化定时器

TMOD = 0x01; //定时器模式

TH0 = (65536-50000)/256; //装初值 TL0 = (65536-50000)%256; EA = 1;//开总中断 ET0 = 1;//开定时器0中断

TR0 = 1; //启动定时器,此时开始计时 }

void timer0() interrupt 1 //定时器0的中断处理函数 {

TH0 = (65536-50000)/256; //装初值 TL0 = (65536-50000)%256; timer_count ++;

if(20==timer_count) //到了1秒更新时分秒的显示 {

timer_count = 0; //中断次数清0,重新计数 second ++; //秒针加1 if(second==60) {

second = 0;

minute ++; //分针加1 if(60==minute)

{

minute = 0;

hour ++; //小时加1 if(24==hour) {

hour = 0; }

write_add(0x40+4,hour); }

write_add(0x40+7,minute); //更新分针的显示 }

write_add(0x40+10,second); //更新秒针 } }