51单片机lcd实现时间显示，可调时间和闹钟c语言

以下是一个基于51单片机的LCD实现时间显示、可调时间和闹钟的C语言程序：

#include <reg51.h>

#define LCD_Data_Port P2
#define LCD_Command_Port P3

sbit RS = P0^0;
sbit RW = P0^1;
sbit EN = P0^2;

unsigned char second = 0;
unsigned char minute = 0;
unsigned char hour = 0;
unsigned char alarm_hour = 0;
unsigned char alarm_minute = 0;
unsigned char alarm_flag = 0;

void delay(unsigned int time) {
    unsigned int i, j;
    for(i = 0; i < time; i++) {
        for(j = 0; j < 1275; j++);
    }
}

void lcd_write_command(unsigned char command) {
    LCD_Data_Port = command;
    RS = 0;
    RW = 0;
    EN = 1;
    delay(1);
    EN = 0;
}

void lcd_write_data(unsigned char data) {
    LCD_Data_Port = data;
    RS = 1;
    RW = 0;
    EN = 1;
    delay(1);
    EN = 0;
}

void lcd_init() {
    lcd_write_command(0x38); // 8-bit data, 2-line display, 5x7 font
    lcd_write_command(0x0C); // Display on, cursor off, blink off
    lcd_write_command(0x01); // Clear display
    lcd_write_command(0x06); // Entry mode: increment, no shift
    lcd_write_command(0x80); // Set DDRAM address to 0
}

void display_time() {
    lcd_write_command(0x80); // Set DDRAM address to 0
    lcd_write_data(hour / 10 + '0');
    lcd_write_data(hour % 10 + '0');
    lcd_write_data(':');
    lcd_write_data(minute / 10 + '0');
    lcd_write_data(minute % 10 + '0');
    lcd_write_data(':');
    lcd_write_data(second / 10 + '0');
    lcd_write_data(second % 10 + '0');
}

void display_alarm() {
    lcd_write_command(0xC0); // Set DDRAM address to 40
    lcd_write_data('A');
    lcd_write_data('L');
    lcd_write_data('A');
    lcd_write_data('R');
    lcd_write_data('M');
    lcd_write_data(':');
    lcd_write_data(alarm_hour / 10 + '0');
    lcd_write_data(alarm_hour % 10 + '0');
    lcd_write_data(':');
    lcd_write_data(alarm_minute / 10 + '0');
    lcd_write_data(alarm_minute % 10 + '0');
}

void interrupt timer0_isr() interrupt 1 {
    TH0 = 0xFC;
    TL0 = 0x67;
    second++;
    if(second == 60) {
        second = 0;
        minute++;
        if(minute == 60) {
            minute = 0;
            hour++;
            if(hour == 24) {
                hour = 0;
            }
        }
    }
}

void main() {
    TMOD = 0x01; // Timer0 mode 1: 16-bit timer
    TH0 = 0xFC; // Initialize timer0 to generate interrupt every 500ms
    TL0 = 0x67;
    TR0 = 1; // Start timer0
    ET0 = 1; // Enable timer0 interrupt
    EA = 1; // Enable global interrupt
    lcd_init();
    while(1) {
        display_time();
        if(alarm_flag == 1 && hour == alarm_hour && minute == alarm_minute) {
            lcd_init();
            display_alarm();
            while(1); // Wait for reset
        }
        if(P1_0 == 0) { // Increment hour
            delay(20);
            if(P1_0 == 0) {
                hour++;
                if(hour == 24) {
                    hour = 0;
                }
                while(P1_0 == 0);
            }
        }
        if(P1_1 == 0) { // Increment minute
            delay(20);
            if(P1_1 == 0) {
                minute++;
                if(minute == 60) {
                    minute = 0;
                }
                while(P1_1 == 0);
            }
        }
        if(P1_2 == 0) { // Set alarm
            delay(20);
            if(P1_2 == 0) {
                alarm_hour = hour;
                alarm_minute = minute;
                alarm_flag = 1;
                lcd_init();
                display_alarm();
                while(P1_2 == 0);
            }
        }
    }
}

该程序使用定时器0以1秒为单位跟踪时间，并且可以通过按下按钮来增加小时和分钟，以设置时间和闹钟。如果闹钟时间到达，LCD将显示“ALARM: HH:MM”，并且程序将停止，直到被重置。