Re: Need Help "PPP for 16 bit microcontroller"

[Joel Sherrill <joel dot sherrill at OARcorp dot com>]

It sounds like you have not verified the proper operation of
the communications port software on the embedded side.  You
need to test that thoroughly before moving on to the more
complicated PPP.

FWIW there is now an H8 port of RTEMS and RTEMS includes
a PPP stack.  Your communications device driver still has
to work but unless PPP is the focus of your thesis, it
should save you a lot of time.

Syed Raza wrote:
> 
> Hai All
> 
> I am developing PPP for 16 bit micronotroller (EVB3067).Its a very
> minimal
> implementation of PPP.
> 
> I am trying to establish connection between linux and hitachi
> evaluation board. I am
> using 3 SCI port of Hitachi board. 1 for PPP connection 2nd for
> downloading the
> code and 3rd is to provide debugging information on hyperterminal(as i
> can not use printf() function )
> 
> I am having the folowing problems:
> 
> - I am not able to convert the ASCI characters into Hexadecimal or
> Decimal format which i received in from Client.Is there a problem of
> Library,i mean i am using
> 
> newlib-1.8.2
> gcc-2.95.2
> binutils-2.9.1
> gdb-4.18
> 
> I am using Hitachi Deg Interface under NT,for compiling the program i
> am using Linux
> 
> - I tested my program on Hyperterminal just to cheach if the it works
> fine as there is no other  i can cheack it before i started a real PPP
> connection.But now i am trying to do the real connection by using the
> PPP between linux and my hitachi board.But now the real problem
> started, i want to read the PPP frame which is in HDLC format and then
> reply to peer after doing the Frame cheack seq ...etc(all what is
> required by reall/standard PPP implementation)and cheacking if all the
> field is valid.
> 
> - But what i am getting is garbage, and what Linux is receiving is
> also garbage.Some how data is corrupted.and connection can not
> establish
> 
> - I also notice that some of my function is *NOT working properly
> (though there is nothing wrong in the C code it self).My question is
> is there any way to provide the more debugging info so that my HDI
> will read the program efficently,I tried O,O1,....no success
> 
> > /******************************************************************************
> > First state machine for receiving the frame from PPP_BEGIN_FLAG to
> > PPP_END_FLAG
> > *******************************************************************************/
> >
> > void handle_char (unsigned char r){
> > unsigned char tmp[100];
> > unsigned char tmp1[100];
> > switch (state){
> >   case not_reading:
> >       if(r == PPP_BEGIN_FLAG)
> >         putstring"PPP BEGIN FLAG received....\n");
> >       state = reading;
> >       break;
> >       case reading:
> >  switch(r){
> >  case PPP_END_FLAG:
> >  printf(" PPP END FLAG is received\n ");
> >  frame_check();
> >  if (cheack_fcs() != 0)
> > {
> > putstring("not the correct packet\n\r");
> > break;
> > }
> > buff[0] = PPP_BEGIN_FLAG;
> > buff[1] = 0xff;
> > buff[2] = 0x3;
> > *(unsigned short *) &(buff[3]) = 0xc021;
> > buff[4] = 0x2;
> 
>  buff[41] = PPP_END_FLAG
> 
> > for(num_char_transmit = 0;num_char_transmit <
> > 41;num_char_transmit++)
> > transmit(buff[num_char_transmit]);
> > memcpy(tmp,&buff[4],1);
> > sprintf(tmp1,"%u",tmp);
> > putstring("this is decimal field \n\r");
> > putstring(tmp1);
> > putstring("received PPP FRAME: \n");
> > putstring(buff);
> > num_char_read = 0;
> > state = not_reading;
> > break;
> > default:
> > if (num_char_read == BUFSIZE)
> > {
> > putstring("buffer is  FULL..\n\r" );
> > break;
> > }else{
> >  buff[num_char_read++] = r;
> > break;
> >       }
> >     }
> >   }
> > }
> 
> ======================================================
> 
> Any of the Help,idea or trick will be wellcome, as this is my thesis
> of BEng and i need to soon please reply
> 
> Best regards
> 
> Syed
> -------------VTT - Technical Research Centre of Finland-----------
> Syed Raza
> VTT-Electronics
> P.O.Box 1100
> FIN-90571 Oulu, Finland
> 
> Email: Syed.Raza@vtt.fi
> URL: www.ele.vtt.fi
> Tel: (Res)+358 8 880 4183
> Tel: (off)  +358 8  551 2439.
> Fax: (off) +358 8 551 2320.
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-- 
Joel Sherrill, Ph.D.             Director of Research & Development
joel@OARcorp.com                 On-Line Applications Research
Ask me about RTEMS: a free RTOS  Huntsville AL 35805
Support Available                (256) 722-9985

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