485.c

STC的485中断发送与接收应用请大家使用

#include <intrins.h>
#include <string.h>
#include "5410ad.h"

sbit CKXZA = P2^2;					 /* 4052选通(1) */
sbit CKXZB = P2^3;					 /* 4052选通(2) */
sbit EN485 = P2^5;					 /* 485使能 */
//AE 28 54 73 34 10 20 25
#define INBUF_LEN 8   //数据长度

unsigned char inbuf1[INBUF_LEN];
unsigned char checksum,count3;
bit           read_flag=0;
void init_serialcomm(void)
{
    SCON  = 0x50;       //SCON: serail mode 1, 8-bit UART, enable ucvr 
    TMOD |= 0x20;       //TMOD: timer 1, mode 2, 8-bit reload 
    PCON |= 0x80;       //SMOD=1; 
    TH1   = 0xF4;       //Baud:4800  fosc=11.0592MHz 
    IE   |= 0x90;       //Enable Serial Interrupt 
    TR1   = 1;          // timer 1 run 
   // TI=1; 
}
void send_char_com(unsigned char ch)   // 发送一个字符   
{
    SBUF=ch;	 
    while(TI==0);
    TI=0;
}

void send_string_com(unsigned char *str,unsigned int strlen)  //发送一个字符串，strlen为该字符串长度
{
    unsigned int k=0;
    do 
    {
        send_char_com(*(str + k));
        k++;
    } while(k < strlen);
}
void serial () interrupt 4 using 3 //串口接收中断函数
{
    if(RI)
    {
        unsigned char ch;
        RI = 0;
        ch=SBUF;
        if(ch>127)
        {
             count3=0;
             inbuf1[count3]=ch;
             checksum= ch-128;
        }
        else 
        {
             count3++;
             inbuf1[count3]=ch;
             checksum ^= ch;
             if( (count3==(INBUF_LEN-1)) && (!checksum) )
             {
                 read_flag=1;  //如果串口接收的数据达到INBUF_LEN个，且校验没错， 
                               //就置位取数标志 
             }
        }
    }
}
main()
{
	CKXZA = 0; CKXZB = 0;
	EN485=0;
    init_serialcomm();  //初始化串口 
    while(1)
    {
          if(read_flag)  //如果取数标志已置位，就将读到的数从串口发出 
          {
		  	   EN485=1;
               read_flag=0; //取数标志清0
			   _nop_(); _nop_(); _nop_(); _nop_(); _nop_(); 
               send_string_com(inbuf1,INBUF_LEN);
			   EN485=0;
			   _nop_(); _nop_(); _nop_(); _nop_(); _nop_();
          }
    }

}