HALF DUPLEX COMMUNICATION USING RS-232 IN C (FILE PASSING)

          HALF DUPLEX COMMUNICATION USING RS-232 IN C (FILE PASSING)

                             FILE TRANSMITTER -RECEIVER

#include<stdio.h>

#include<io.h>

#include<dos.h>

#include<conio.h>

#include<bios.h>

#define COM1 0

#define COM1ADDR 0x3F8

#define DATA_READY 0x100

#define TRANS_READY 0x2000

main()

{

              char tfile,ch,rfile;

              int status,counter=0;

              long size;

              char setting,baud = 0xa0,parity = 0x08,data = 0x04,stop = 0x03;

              FILE *fpt;

              FILE *fpr;

              setting = baud | parity | data | stop;

              clrscr();

              bioscom(0,setting,COM1);

              printf("\n\tEnter Filename To Transfer : ");

              scanf("%s",tfile);

              fpt = fopen("c:\\1.txt" ,"r");

              if(fpt == NULL)

              {

                        printf("\n\tFile Not Found.....\n");

               }

              else

              {

                        fseek(fpt,0,SEEK_END);

                        size = ftell(fpt);

                        printf("\n\tFile size is %ld",size);

                        rewind(fpt);

                        printf("\n\tFile is being transferred\n\tWait...\n");

                        while(!feof(fpt))

                        {

                                  status=bioscom(3,0,COM1);

                                  if(status & TRANS_READY)

                                  {

                                           ch=fgetc(fpt);

                                           outport(COM1ADDR,ch);

                                           counter++;

                                           gotoxy(20,20);

                                           printf("%d Bytes has been transfered",counter);                                       }

                                     }

                                     outport(COM1ADDR,0x1b);

                                     printf("\n\tFile transferred successfully");

                                     getch();

                            }

                            printf("\n\tEnter file to receive: ");

                            scanf("%s",rfile);

                            fpr = fopen( rfile,"w");

                            if(fpr == NULL)

                            printf("\n\tError...File cannot be opened");

                            else

                            {

                                     bioscom(0,setting,COM1);

                                     while(1)

                                     {

                                              status=bioscom(3,0,COM1);

                                              if(status & DATA_READY)

                                              {

                                                        ch = inport(COM1ADDR);

                                                        fputc(ch,fpr);

                                                         if(ch== 0x1b)

                                                         break;

                                                         printf("%c",ch);

                                              }

                                     }

                                       }

                  }