51单片机lcd显示时间闹钟蜂鸣器

以下是51单片机lcd显示时间闹钟蜂鸣器的代码示例：

#include <reg51.h>
#include <intrins.h>

#define uchar unsigned char
#define uint unsigned int

sbit beep = P1^5;
sbit dula = P2^6;
sbit wela = P2^7;

uchar code table[] = {
    0x3f,  // 0
    0x06,  // 1
    0x5b,  // 2
    0x4f,  // 3
    0x66,  // 4
    0x6d,  // 5
    0x7d,  // 6
    0x07,  // 7
    0x7f,  // 8
    0x6f   // 9
};

uchar hour = 10;  // 初始时间为10:00
uchar minute = 0;
uchar second = 0;
uchar alarm_hour = 12;  // 初始闹钟时间为12:00
uchar alarm_minute = 0;
bit alarm_flag = 0;  // 闹钟标志位

void delayms(uint x) {  // 毫秒级延时函数
    uint i, j;
    for (i = x; i > 0; i--) {
        for (j = 110; j > 0; j--);
    }
}

void display(uchar hour, uchar minute) {  // 在LCD上显示时间
    uchar shiwei = hour / 10;
    uchar gewei = hour % 10;
    P0 = 0xff;
    wela = 1;
    wela = 0;
    P0 = ~(0x01 << 1);
    dula = 1;
    dula = 0;
    P0 = table[shiwei];
    wela = 1;
    wela = 0;
    P0 = ~(0x01 << 0);
    dula = 1;
    dula = 0;
    P0 = table[gewei];
    wela = 1;
    wela = 0;
    P0 = ~(0x01 << 3);
    dula = 1;
    dula = 0;

    shiwei = minute / 10;
    gewei = minute % 10;
    P0 = 0xff;
    wela = 1;
    wela = 0;
    P0 = ~(0x01 << 5);
    dula = 1;
    dula = 0;
    P0 = table[shiwei];
    wela = 1;
    wela = 0;
    P0 = ~(0x01 << 4);
    dula = 1;
    dula = 0;
    P0 = table[gewei];
    wela = 1;
    wela = 0;
    P0 = ~(0x01 << 7);
    dula = 1;
    dula = 0;
}

void main() {
    TMOD = 0x01;  // 设置定时器0为16位定时器
    TH0 = 0x3c;  // 给定时器0赋初值，定时1ms
    TL0 = 0xb0;
    TR0 = 1;  // 启动定时器0
    ET0 = 1;  // 打开定时器0中断
    EA = 1;  // 打开总中断开关

    while (1) {
        display(hour, minute);

        if (alarm_flag) {  // 闹钟响起
            for (int i = 0; i < 1000; i++) {
                beep = ~beep;
                delayms(1);
            }
            alarm_flag = 0;
        }
    }
}

void timer0() interrupt 1 {  // 定时器0中断服务程序
    TH0 = 0x3c;
    TL0 = 0xb0;
    second++;

    if (second >= 60) {
        second = 0;
        minute++;
    }

    if (minute >= 60) {
        minute = 0;
        hour++;
    }

    if (hour >= 24) {
        hour = 0;
    }

    if (hour == alarm_hour && minute == alarm_minute) {  // 判断是否到达设定的闹钟时间
        alarm_flag = 1;
    }
}

该代码中使用了定时器0进行时间计数，并通过LCD显示时间。同时设定了闹钟时间，当时间到达设定的闹钟时间时，蜂鸣器会响起。