max232.c

2232接收 232接收 232接收

#include<reg51.h>
#define uchar unsigned char
#define uint unsigned int
#define TR 0
uchar idata buf[10]={0x20,1,2,3,4,5,6,7,8,9};
uchar pf;


void init(void)
{TMOD=0x20;               //mode 1,counter 1
 TH1=0xFD;                //set baud rate
 TL1=0xFD;
 PCON=0x00;
 TR1=1;                   //start T/C1
 SCON=0x50;               //mode1
}


void send(uchar idata *d)
{uint i;
 uchar j,v;
 P1=0Xfb;
 do{RI=0;
   SBUF=0xaa;           //send handshaking message
    while (TI==0);       //sending
  TI=0;                //software clear
   while(RI==0);        //waiting for ACK
  RI=0;
  v=SBUF;                //software clear
 }while (v!=0xbb);//B is not ready
   do{
     pf=0;                 //clear the sum
     for(i=0;i<10;i++){
       j=*(d+i);
	   SBUF=j ;         //send the data
       pf+=*(d+i);           //sum
       while(TI==0);TI=0;  
       }
     SBUF=pf;               //send sum
    while(TI==0);TI=0;
  while(RI==0);RI=0;     //waiting for B to ack
     }while (SBUF!=0);     //if there is wrong, send again
}

void receive(uchar idata *d)
{uchar i;
 do{
    while(RI==0);RI=0;      
   } while((SBUF^0xaa)!=0); //check if A is sending
   SBUF=0xbb;               //send ACK
   while(TI==0);TI=0;
   while(1){
    pf=0;
    for(i=0;i<16;i++){
    while(RI==0);RI=0;
    d[i]=SBUF;              //receive data
    pf+=d[i];               //sum
    }
    while (RI==0);RI=0;     //receive sum
    if((SBUF^pf)==0){       //check sum
     SBUF=0x00;break;}      //if the two are equal, then send 00
    else{
      SBUF=0xff;            //send FF,receive again
      while(TI==0);TI=0;
   }
  }

 }

void main(void){
 init();
 if(TR==0){
    send(buf);
}
//else{
 //receive(buf);
//}
}