各位大神好,一直对蜂鸣器唱歌很感兴趣,前几天在我们这个论坛发现了一个关于蜂鸣器唱歌的程序,程序如下:
/************************************************ 跳线设置: 1.蜂鸣器和继电器 共用p2.2 ,跳线J5设置到23端选中蜂鸣器 2.J7拔掉,双排针除PSEN外全部插上
效果: 1,生日快乐歌曲 相关知识点: 1,利用单片机的定时器精准定时 ************************************************/
#include"AT89x52.h" #define uchar unsigned char #define uint unsigned int sbit P22=P2^2; uchar i,j,time1,time2; uint code array1[]={ 400,400,650,650,650,1200, 400,400,650,650,650,1200, 400,400,650,650,650,650,1200, 400,400,650,650,650,1200 }; uchar code array[]={ 0xfd,0x79,0xfd,0x79,0xfd,0xc7,0xfd,0x79,0xfe,0x21,0xfe,0x05, 0xfd,0x79,0xfd,0x79,0xfd,0xc7,0xfd,0x79,0xfe,0x51,0xfe,0x21, 0xfd,0x79,0xfd,0x79,0xfe,0xc0,0xfe,0x84,0xfe,0x21,0xfe,0x05,0xfd,0xc7, 0xfe,0x99,0xfe,0x99,0xfe,0x90,0xfe,0x21,0xfe,0x51,0xfe,0x21 };
void delay(uint m) { uint n; for(;m>0;m--) for(n=125;n>0;n--); }
void main() { TMOD=0x01; TH0=0; TL0=0; EA=1; ET0=1; TR0=1; while(1) { time1=array[i++]; time2=array[i++]; if(i==50) i=0; delay(array1[j++]); if(j==25) j=0; }
} void init() interrupt 1 { TR0=0; P22=~P22; TH0=time1; TL0=time2; TR0=1; }
但是,我不太理解这程序的思路,求各位前辈高人帮我解释下,我对蜂鸣器唱歌的理解是在一段时间里面,输出不同频率的方波给蜂鸣器引脚,不知道这样对不对,另外从程序上怎么体现出来,希望高手可以帮我把这程序讲解下,最好是每行都注释一下,我是新手,谢谢你的解惑和不吝赐教!谢谢! |