单片机实验7：定时器控制灯泡的亮与灭

定时器控制灯泡的亮与灭，亮时蜂鸣器发声

实验晶振11.0592，灯泡亮灭各1s

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

uchar num;		     //全局变量
sbit led = P2^0;	 //led灯
sbit beep = P1^5;	 //蜂鸣器

void delay(int i)	//延时，用于控制蜂鸣器的音调
{
    
    
	while(i--);
}

void main()
{
    
    

	led = 0;
	TMOD = 0x01;
	TH0 = (65536-45872)/256;
	TL0 = (65536-45872)%256;
	EA = 1;
	ET0 = 1;
	TR0 =1;
	while(1)
	{
    
    
		if(num == 20)
		{
    
    
			num = 0;
			led = ~led;
		}
		if(led == 0)
		{
    
    
			beep = ~beep;
			delay(10);
		}
	}
}

void TR0_time() interrupt 1		定时器中断程序
{
    
    
	TH0 = (65536-45872)/256;
	TL0 = (65536-45872)%256;
	num++;
}