ex.c

80C51单片机中利用蜂鸣器实现电子琴的源程序。包含蜂鸣器的datasheet。

#include "reg52.h"

sbit P3_3=P3^3;

unsigned char idata i,tl0_temp=0,th0_temp=0;

void INTTO() interrupt 1 
{
	TH0=th0_temp;
	TL0=tl0_temp;
	P3_3=~P3_3;
}

main()
{
	P1=0XFF;
	TMOD=0X01;	
	ET0	=1;
	EA	=1;
	TH0=0;
	TL0=0;
	TCON	=0x10;	
	while(1)
	{
		i=P1;
		if(i==0xff)
			TR0=0;
		if(i==0xfe)
		{
			th0_temp=0xfb;
			tl0_temp=0xE9;
			TR0	=1;	
		}
		if(i==0xFD)
		{
			th0_temp=0xFC;
			tl0_temp=0x5C;
			TR0=1;	
		}
		if(i==0xFB)
		{		
			th0_temp=0xFC;
			tl0_temp=0xc1;
			TR0	=1;	
		}
		if(i==0xF7)
		{
			th0_temp=0xFC;
			tl0_temp=0xEF;
			TR0	=1;	
		}
		if(i==0xEF)
		{		
			th0_temp=0xFD;
			tl0_temp=0x45;
			TR0	=1;	
		}
		if(i==0xDF)
		{		
			th0_temp=0xFD;
			tl0_temp=0x92;
			TR0	=1;	
		}
		if(i==0xBF)
		{		
			th0_temp=0xFD;
			tl0_temp=0xD6;
			TR0	=1;	
		}
	}
}