AVR第5课：蜂鸣器

下面是蜂鸣器的电路图。

代码：蜂鸣器代码。

<span style="font-size:18px;">/*
*info:buzzer
*author:chenlu
*date:2014.11.20
*/

//input the head file so that the program can work normally
//iom16v---know the register
//macros---know the BIT(x)
#include<iom16v.h>
#include<macros.h>
//use those can make your study very conveninet
#define uint unsigned int
#define uchar unsigned char

//display methods
void initSystem();
void delay();

//the main function
void main()
{
 	//init your system
	initSystem();
	while(1)
	{
	  	//start your function,and this is core solution
		PORTA = PORTA & (~BIT(1));
		delay();
		delay();
		delay();
		delay();
		PORTA = PORTA | BIT(1);
		delay();
		delay();
		delay();
		delay();
	}
}

//the method of init system
void initSystem()
{
 	//to make PA1 port output
	DDRA = DDRA | BIT(1);
	//to make PA1 port output high level
	PORTA = PORTA | BIT(1);
}

//the sub method of delay
void delay()
{
 	uchar i,j;
 	for(i=0;i<250;i++)
	  for(j=0;j<250;j++);
}</span>

让蜂鸣器响一下，接着停一下，如此循环。