STC89C52单片机学习（一）----点亮LED

1.通过数组实现led流水灯

#include 

int m;
unsigned char code leds[8] = {0x7f, 0xbf, 0xdf, 0xef, 0xf7, 0xfb, 0xfd, 0xfe};

void delay(unsigned int i)
{
	unsigned int j;
	unsigned char k;

	for(j=i; j>0; j--)
		for(k=125; k>0 ;k--);
}

int main()
{		
	while(1)
	{
		for(m = 0; m < 8; m++)
		{		
			P1 = leds[m];
			delay(500);				
		}		
	}

	return 0;
}

使用 if语句实现led灯的控制，i类似于标志位控制进行循环转移

i = 0;
while(1)
{
	P1 = leds[i++];
	delay(5000);
	if(i == 8) i = 0;
}

2.通过独立按键实现LED灯的闪烁流动

运用独立按键需I/O端口，预先置高，表示作为输入端

#include 

sbit k1 = P3^4;

unsigned int m;
unsigned char code leds[8] = {0x7f, 0xbf, 0xdf, 0xef, 0xf7, 0xfb, 0xfd, 0xfe};

void delay(unsigned int i)
{
	unsigned int j;
	unsigned char k;

	for(j=i; j>0; j--)
		for(k=125; k>0; k--);
}

int main()
{
	k1 = 1;
		
	while(1)
	{
		for(m = 0; m < 8; )
		{
			P1 = leds[m];
			delay(500);	

			if(k1 == 0)
			{
				delay(80);
				if(k1 == 0)
				m++;	
			}			
		}		
	}

	return 0;
}

3.外部中断1实现按键闪烁

1）.实现部分在中断函数里

#include 

sbit p3_4 = P3^4;

unsigned int m;
unsigned char code leds[8] = {0x7f, 0xbf, 0xdf, 0xef, 0xf7, 0xfb, 0xfd, 0xfe};

void delay(unsigned int i)
{
	unsigned int j;
	unsigned char k;

	for(j=i; j>0; j--)
		for(k=125; k>0; k--);
}

int main()
{
	EA = 1;
	EX1 = 1;
	IT1 = 1;

	p3_4 = 0;
	P1 = leds[0];	
	while(1);

	return 0;
}

void led_key() interrupt 2
{
	if(m <= 7)
	{
		P1 = leds[m++];
		delay(500);	
		//m++;	
	}
	else
		P1 = leds[0];			
} 
   
 
   
 
   
2)实现部分在主函数中
 
  

bit flag;         //标志位


while(1)
{
	for(m = 0; m < 8; )
	{
		P1 = leds[m];
		delay(500);	

		if(flag == 1)
		{
			delay(80);			 //去抖 -----中断
			if(flag == 1)
				m++;	
		}			
	}		
}


void led() interrupt 0
{
	flag = 1;
}