PING from Windows to a serial port

Ya know, for somebody that knows virtually nothing about TCP/IP in specific [and computers in general according to the archives], you sure have an interesting approach when it comes to getting along with others while asking for their help. I guess you are right though. Help you, not help you; it's really not that important. I'll make a personal effort to not try helping you again with your problems.

I think I'll also make a practice of not recommending your dev boards to anyone either. [and you thought top-posting didn't matter] Given the nature of your previous problems getting this SLIP thing to work and looking at other "problems" you've brought to USENET, one can only wonder how you managed to actually bring a product all the way to market.

BTW, your "About Us" page is a hoot. Try to imagine my surprise, I actually expected to see something about you listed out there. You know, like experience and accomplishments or, lacking that, your educational credentials. Perhaps you could call it the "How to Pay Me" page instead. ;-)

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He is obviously just a rude and ignorant boor. PLONK.

--
"If you want to post a followup via groups.google.com, don't use
 the broken "Reply" link at the bottom of the article.  Click on 
 "show options" at the top of the article, then click on the 
 "Reply" at the bottom of the article headers." - Keith Thompson

OK guys, enough.. I understand.. ;-)

I also understand that the tool is probably a big part in the problem, because it's effectively really simpler and instinctive to do "top-posting" with Outlook Express.. but it's also really easy to trim the unrelevant part.. :-)

Weird!!

Why is this such a big deal?

Rog.

-- Grant Edwards grante Yow! I HAVE a towel. at visi.com

It's protocol, which I imagine you can appreciate given your current project.

Even if you disagree, it's easy enough to comply. Especially when it's important in the community where you're soliciting free help...

Nicely put. However does it excuse a verbal personal attack?

[Last posting]

Nicely put. However does it excuse a verbal personal attack?

[Last posting]

Richard,

Sorry you also asked a couple of questions a few postings ago - I'd forgotten them amid all this abuse coming my way!

I'm using an AVR M128, the stock processor for much of the work I do. A simple web page server is something that I've wanted to get into for a while and having a web page interface for an embedded system is the best way in my opinion. I thought of getting into a 3rd party solution but the best way to learn something is to "do" it. I'll be moving on to some ARM7 work later and want to be able to simply port my code across. As everyone who's read the postings, it's something new to me but I'm nearly at the PING stage now and the TCP part should be easy enough. The CGI and http part will be the hardest I think.

Thanks for the help, regards,

Roger.

Get the book, really. The time it will save you will more than make up for the cost and time to read it. The project is bigger than it seems - SLIP+ICMP is a toe in the water.

ARP, ICMP, and UDP are relatively easy. TCP will be hard, as you need to negotiate / maintain a state table for each connection, etc. All the other protocols & parts are very much "fire & forget".

Particularly for TCP, SLIP is harder than Ethernet because you don't have the NIC buffer RAM to hold the packet while you checksum it. Bentham has a very creative technique that's an alternative to setting aside several hundred bytes of sparse SRAM.

There are also tricks to doing non-trivial variable input and dynamic graphical output with limited file storage. Several of the techniques Bentham presents are pretty slick, and saves loads of time doing the initial discovery yourself.

Finally, there are open projects out there like Ethernut.de using the AVR for Ethernet. (Don't forget, you'll also be needing driver code for an Ethernet controller.)

While all of these resources may have commercial limitations on the source code, they'll make great references as you craft your own code, and help you asses how big the project really will be. After all, why re-invent the wheel unless you're in this project purely for mental stimulation?

On the other hand, products like Lantronix XPort and Digi's Digi-ME web-server-in-an-RJ-45-jack are more expensive, but very compact, very quick time-to-market, and zero overhead on your MCU (and there's a dozen other popular options). Unless Ethernet connectivity is your core product, it might make better business sense to spend time & effort enhancing your core product line and using a turnkey solution to add Ethernet.

Richard

And/or get "TCP/IP Illustrated" by W. Richars Stevens. It's even available online (unixforge?) and IMHO gives a better picture of how things work together. You won't find implemetation details etc, though.

Andreas

--
A: Because it messes up the order in which people normally read text.
Q: Why is top-posting such a bad thing?
A: Top-posting.
Q: What is the most annoying thing on usenet?

You *do* need the W. Richard Stevens' books.

An AVR is a little on the light side to make a working TCP/IP stack. For references how much can be skipped, get Jeremy Bentham's TCP/IP Lean.

Also, get Ethereal and learn to use it - you need it.

Been there - done that (on an AT91 ARM7TDMI).

--

Tauno Voipio
tauno voipio (at) iki fi

Agreed, sortof. Implementation on MCUs is specific enough the I'd recommend TCP/IP Lean over the Stevens book. There are a lot of corners to cut and tricks involved.

But that said, if I only had one IP reference, it'd be Stevens, Volume

1. It's indispensable. Despite being 12 years old, there's little that's outdated. (I hadn't heard it was available online now - that's great.) Here's the book:
   formatting link

Volume 2 covers implementation on Unix, and is fairly useful, but not nearly as much as the first volume.

But don't try to craft your packet formats based purely on the book - options like Ethernet frame types, etc. will confuse matters. It's much easier to copy the frame format from a real packet and use Volume 1 to understand how it works. As Tauno mentioned, Ethereal

is free and absolutely indespensible (and in many regards, better than the original $10K Sniffer product).

Richard

Thanks everyone. I'll get onto Amazon.

Rog.