#include<reg51.h>

#define uchar unsigned char
#define uint  unsigned int

uchar temp[30];
uchar len = 0;
bit flag_L;

void delay_50us(uchar t)
{
	uchar i;
	for(;t>0;t--)
	for(i=23;i>0;i--);
}

void  Inituart(void)
{
	TMOD = 0X20;
	TH1 = 0XF3;     //波特率4800bit/s 晶振12MHz
	TL1 = 0XF3;
	SCON = 0X50;
	PCON = 0X80;
	IE = 0x90;
	TR1=1;
}

void main()
{
	uchar i;
	uint t;
	flag_L = 0;
	Inituart();
	while(1)
	{
		t = 65535;
		while(len)
		{
			if(flag_L)
			{
				for(i=0;i<10;i++)
				{
					SBUF = temp[i];
					while(TI == 0);
					TI = 0;
				}
				delay_50us(100);
				flag_L = 0;
				len = 0;
				break;
			}
			t --;
			if(t == 0)
			{
				len = 0;
				flag_L = 0;
				SBUF = 0x45;
				while(TI == 0);
				TI = 0;
				break;
			}		
		}	
	}
}

void serial () interrupt 4 using 3  
{  
	if(RI)
	{
		RI = 0;
		if(len < 10)
		{
			temp[len] = SBUF;
			len++;
		}
	}
	if(len == 10)
	{
		flag_L = 1;
	}
}