alarm.c

来自「单片机控制报警器进行异常报警 报警可以设置」· C语言 代码 · 共 97 行

/********************************************************************************
*  描述:                                                                       *
*         单片机模拟报警声                                                     *
*                                                                              *
*                                                                              *
*                                                                              *
********************************************************************************
* 【声明】 此程序仅用于学习与畔ⅲ?                 *
*******************************************************************************/
                   
#include <reg51.h>
#include <intrins.h>

sbit	SPK = P3^3;

unsigned char frq; 

void delayms(unsigned char ms);

main()
{
	TMOD = 0x01;
	frq = 0x00;
	TH0 = 0x00;
	TL0 = 0xff;	
	TR0 = 1;
	IE = 0x82;
	
	while(1)
	{
		frq++;
		delayms(1);

	}
}

void timer0() interrupt 1 using 1
{
	TH0 = 0xfe;
	TL0 = frq;
	SPK = ~SPK;	
}

void delayms(unsigned char ms)	
// 延时子程序
{						
	unsigned char i;
	while(ms--)
	{
		for(i = 0; i < 120; i++);
	}
}

/*在下面改动		 
#include <reg51.h>
#include <intrins.h>

sbit	SPK = P3^3;

unsigned char frq; 

void delayms(unsigned char ms);

main()
{
	TMOD = 0x01;
	frq = 0x00;
	TH0 = 0x00;
	TL0 = 0xff;	
	TR0 = 1;
	IE = 0x82;
	
	while(1)
	{
		frq++;
		delayms(1);

	}
}

void timer0() interrupt 1 using 1
{
	TH0 = 0xfe;
	TL0 = frq;
	SPK = ~SPK;	
}

void delayms(unsigned char ms)	
// 延时子程序
{						
	unsigned char i;
	while(ms--)
	{
		for(i = 0; i < 120; i++);
	}
}*/