----- Original Message ----- 
From: "Byron A Jeff" <byron@cc.gatech.edu>
To: "Microcontroller discussion list - Public." <piclist@mit.edu>
Sent: Tuesday, May 03, 2005 12:22 PM
Subject: Re: [PIC] Need help with embedded web server


> On Tue, May 03, 2005 at 01:13:53AM +0100, kerrisnow@btinternet.com wrote:
> > Here is my plan:
>
> Sorry I'm late to the party.
>
> >
> > I would like to use the pic18f2455 to create a web server. I am not
> > going to use ethernet or eeprom. I will connect it to my pc
> > with the serial cable. The other end of the cable will connect to the
> > serial port of the pic. The pc will connect to the pic with slip for the
> > web server and with hyperterminal instead of the lcd of picdem.net.
> > Does this sound o.k.?
>
> This topic rolls in about twice a year. I always ask the same question
> when I see this setup: Why a web server?
>
> I always ask the question because with the physical interface you specify
> (serial/SLIP) there's no way to build a box that can connect to the
> Internet without a gateway. Now that's OK, but I always question the
> utility of shoving an entire HTTP/TCP/IP/SLIP stack onto the PIC.
>
> The question is also generated based on objective. My objective when I
> was looking at the problem was threefold:
>
> 1) Leverage as much of the TCP/IP standard, which has tons of written and
> tested code, as I could.
>
> 2) Have the potential for true Internet connectivity.
>
> 3) Keep new code/stack on the PIC as small as possible.
>
> This lead me to a UDP/IP/SLIP stack with a PC SLIP gateway. It's a project
> that I put a couple of students on years ago, but never got completely
> fleshed out.
>
> The one downside with my approach is that you do have to have custom
> software on the PC to receive and process packets. But I always looked at
> it as having a big, easy to program PC, as opposed to as a more
constrained
> PIC to work on. Also there are standard programs that can interface with
> UDP ports. netcat for example can be found here:
>
> http://www.securityfocus.com/tools/137
>
> With a tutorial here:
>
> http://m.nu/program/util/netcat/netcat.html
>
> As a linux guy a 5 second Google found this article for a framework for
> UDP applications:
>
> http://www.linuxgazette.com/node/8758
>
> As standard socket code, it should port easily.
>
> But again it depends of the objective. I wasn't looking at the Kewl factor
> of having a webserver on a PIC. It may be a worthy goal if we're talking
> Ethernet or PPP which can connect to the network standalone. But with SLIP
> which virtually requires a gateway, UDP seems to be the ticket for
> delivering content around the network with a PIC.
>
> BTW hyperterminal isn't going to get you where you want to go. You need to
> create a SLIP connection in your dialup networking, and use that to
connect.
Yes, that's because SLIP is going to occupy com1, preventing hyper terminal
from opening it.
>
> Just some thoughts.
>
> BAJ
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