兩個(gè)簡單的報(bào)警程序,希望能對大家有所啟發(fā),讓單片機(jī)發(fā)出更美妙的音響

/***********************************************

* 標(biāo)題: 簡單報(bào)警聲程序

* 日期: 2008-4-30

* yongsheng.gys@163.com

***********************************************/

#include

#include

sbit SPK = P3^4;

unsigned char frq;

void delayms(unsigned char ms)

// 延時(shí)子程序

{

unsigned char i;

while(ms--)

{

for(i = 0; i < 120; i++);

}

}

void timer0() interrupt 1 using 1

{

TH0 = 0xfe;

TL0 = frq;

SPK = ~SPK;

}

main()

{

TMOD = 0x01;

frq = 0x00;

TH0 = 0x00;

TL0 = 0xff;

TR0 = 1;

IE = 0x82;

while(1)

{

frq++;

delayms(1); //改變此處可以改變報(bào)警聲的節(jié)奏長度

}

}

/***********************************************

* 標(biāo)題: 單片機(jī)演奏消防車的報(bào)警聲音

* 日期: 2008-4-30

* yongsheng.gys@163.com

***********************************************/

#include

#include

sbit SPK = P3^4; //喇叭接到P3.4上

unsigned char frq;

unsigned char flag;

void delayms(unsigned char ms)

// 延時(shí)子程序

{

unsigned char i;

while(ms--)

{

for(i = 0; i < 120; i++);

}

}

void timer0() interrupt 1 using 1

{

TH0 = 0xfe;

TL0 = frq;

SPK = ~SPK;

}

void main()

{

TMOD = 0x01;

frq = 0x00;

TH0 = 0x00;

TL0 = 0xff;

TR0 = 1;

IE = 0x82;

flag=0;

while(1)

{

switch(flag)

{ case 0:frq++;break; //flag標(biāo)志置0時(shí),frq遞增

case 1:frq--;break; //flag標(biāo)志置1時(shí),frq遞減

}

if (!(frq^0xff)) flag=1; //當(dāng)frq增加到FFH時(shí),flag置1,準(zhǔn)備frq遞減

if (!(frq^0x00)) flag=0; //當(dāng)frq遞減到00H時(shí),flag置0,準(zhǔn)備frq遞增

delayms(15); //^為邏輯異或改變此值可改變節(jié)奏

}

}