// Terminal - Very plain terminal program.  Simply opens the Port and then
//            Sends keyboard to COM port, and COM port to screen, forever.
//            This program demonstrates the use of Comm.lib.

CommPortName = "COM2";  // Set this to your valid port

#include <Comm.lib>

// Open (try) the port
   printf("Opening port \"%s\"...",CommPortName);
   CommHandle = OpenComm(CommPortName,5000,1000);

   if ( CommHandle < 0 ) {
      switch( CommHandle ) {
         case IE_BADID:    error = "Invalid or unsupported ID";      break;
         case IE_BAUDRATE: error = "Unsupported baud rate";          break;
         case IE_BYTESIZE: error = "Invalid byte size";              break;
         case IE_DEFAULT:  error = "Error in default parameters";    break;
         case IE_HARDWARE: error = "Hardware Not Present";           break;
         case IE_MEMORY:   error = "Unable to allocate queues";      break;
         case IE_NOPEN:    error = "Device not open";                break;
         case IE_OPEN:     error = "Device already open";            break;
         default:          error = "Unknown Error";                  break;
      }
      printf("\n\aError %d opening port: %s.\n",CommHandle,error);
      printf("Press any key to exit...");
      getch();
   } else {

      printf("\nComm port is open. You are in Terminal mode.\n");

      // Set up routine to Close port in case of sudden program exit
      atexit("CloseCommHandle");

      // set port to 9600 baud, 8 bytes, 1 stop bit, no parity
      GetCommState(CommHandle,dcb);
      dcb.Parity = NOPARITY;
      dcb.BaudRate = 9600;
      dcb.StopBits = ONESTOPBIT;
      dcb.ByteSize = 8;
      SetCommState(dcb);

      for ( ; ; ) {  // forever

         // Read whatever characters are in keyboard into a buffer
         if ( kbhit() ) {
            WriteLen = 0;
            do {
               WriteBuf[WriteLen++] = byte(getch());
            } while( kbhit() );
            // write characters from buffer to comm port
            if ( WriteLen != WriteComm(CommHandle,WriteBuf,WriteLen,WriteError)
              || WriteError )
               printf("\n\aWrite Error %04X\n",WriteError);
         }

         // If any bytes available, then write to the screen
         if ( (ReadLen = ReadComm(CommHandle,ReadBuf,200,ReadError)) )
            fwrite(ReadBuf,ReadLen,stdout);
         // If there was a read error then report it
         if ( ReadError )
            printf("\n\aRead Error %04X\n",ReadError);

      }

   }


// This routine will be called to close port when program terminates
   CloseCommHandle()
   {
      CloseComm(CommHandle);
   }