in_485_key.c

单片机控制MAX485的485总线收发程序

#include<at89x52.h>
#include<stdio.h>
#include <intrins.h>

#define uchar unsigned char 			
#define uint unsigned int
sfr dog=0xe1;

//uchar code SST516[3] _at_ 0x003b;
uint com_rxd_data[2];
uint com_rxd_wei=0;
uint code_temp=255;

void main(void)
{
  dog=0x3c;
  SCON = 0x50; //串口方式1,允许接收
  TMOD = 0x20; //定时器1 定时方式2
   //TCON = 0x40; //设定时器1 开始计数
  TH1 = 0xFA; //11.0592MHz 9600 波特率
  TL1 = 0xFA;
  dog=0x3c;
  TI = 1;
  TR1 = 1; //启动定时器
  ES=1;
  EA=1;
  dog=0x3c;
  //RI=0;
  //P2=0xff;
  while(1)
  {
  	dog=0x3c;
  }
}

void com_rxd(void) interrupt 4
{
  if(RI)
  { 
    dog=0x3c;   
    if(com_rxd_wei==3)
	  {	    
	    com_rxd_wei=0;
		dog=0x3c;
	  }
	   com_rxd_data[com_rxd_wei]=SBUF;
	   dog=0x3c;
	   if(com_rxd_data[0]=='K')
	   {
	     com_rxd_wei=com_rxd_wei+1;
		 dog=0x3c;
	   }
	   else
	       {
		   	 com_rxd_wei=0;
			 dog=0x3c;
		   }
	   RI=0;
	   dog=0x3c;
	   if(com_rxd_data[0]=='K'&&com_rxd_data[2]=='T')
	   { 
	     dog=0x3c;    
		 code_temp=com_rxd_data[1];
		 switch (code_temp)
		 {
		    dog=0x3c;
		 	case '0':
				P1_0=0;
				dog=0x3c;
				break;

			case '1':
				P1_1=0;
				dog=0x3c;
				break;

			case '2':
				P1_2=0;
				dog=0x3c;
				break;

			case '3':
				P1_3=0;
				dog=0x3c;
				break;

			case '4':
				P1_4=0;
				dog=0x3c;
				break;

			case '5':
				P1_5=0;
				dog=0x3c;
				break;

			case '6':
				P1_6=0;
				dog=0x3c;
				break;

			case '7':
				P1_7=0;
				dog=0x3c;
				break;




			case 'A':
				P1_0=1;
				dog=0x3c;
				break;

			case 'B':
				P1_1=1;
				dog=0x3c;
				break;

			case 'C':
				P1_2=1;
				dog=0x3c;
				break;

			case 'D':
				P1_3=1;
				dog=0x3c;
				break;

			case 'E':
				P1_4=1;
				dog=0x3c;
				break;

			case 'F':
				P1_5=1;
				dog=0x3c;
				break;

			case 'G':
				P1_6=1;
				dog=0x3c;
				break;

			case 'H':
				P1_7=1;
				dog=0x3c;
				break;

			default:
			    dog=0x3c;
				break;
		}
		 com_rxd_wei=0;
		 dog=0x3c;		
	   }
	   dog=0x3c;	  	   
  }
  dog=0x3c;
}