5buttononekey.c

AVR典型实例.rar

/*
   5ButtonOneKey.C
   5个按钮+4位共阴数码管显示例程
   带软件去抖功能
   作者：吴健
*/
#define F_CPU 4000000UL
#include <avr/io.h>
#include <avr/delay.h>
#define uchar8 unsigned char

const uchar8 LedNum[] ={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f};
uchar8 KeyNum = 0; // 按钮的值
void delay()
{
	int i;
	for(i=0;i<600;i++)
		;
}

void LEDShow(int num)
{
	uchar8 i,tmp,curnum;
	int tmpnum;

		tmp = 0xef;
		tmpnum = num;
		for(i=0;i<4;i++)
		{	
			curnum = tmpnum % 10;
			tmpnum = tmpnum / 10;
			PORTA = tmp;
			PORTC = LedNum[curnum];
			delay();
			tmp = (tmp << 1) + 0x1;
		}

}

// 得到按钮按下所代表的按键号码
uchar8 GetKey(void)
{
    uchar8 keyval;
	keyval = PIND;
    keyval = (~keyval)&0xf8;
	keyval = keyval >>3;
	
	switch(keyval)
	{
	case 0:
		return 0;
	case 1:
	    return 1;
    case 2:
	    return 2;
    case 4:
	    return 3;
    case 8:
	    return 4;
    case 0x10:
	    return 5;
    default:
	    return 0;

	}
	return 0;

}

// 带软件10ms去抖功能的读按钮
uchar8 GetOneKey(void)
{
    uchar8 tmpkey;
    if(GetKey() == 0)
	{
	    KeyNum = 0;
		return KeyNum;
	}else{
        tmpkey = GetKey();
		_delay_ms(10);
		if(tmpkey == GetKey())
		{
		     KeyNum = tmpkey;
			 return KeyNum;
		}
	}
	KeyNum = 0;
	return KeyNum;
}
int main(void)
{
	int num=0; /*  要显示的数字 */
	DDRC = 0xff;
	DDRA = 0xff;
	DDRD = 0; // 输入方式
	
	num = 0;
	while(1)
	{
		LEDShow(num);
		num = GetOneKey();
		delay();
	}
    return 0;
}