Issue
142 May2002
I-Way
the Hard(ware)
Way
THE
PROOF IS IN THE SURFING
Socket-level
programming is all well and good, but for most people
the embedded Internet concept is all about accessing
a gadget’s web page from a standard browser. The folks
at i2Chip oblige with a simple web server demo. Download
webserv.hex to the evaluation board, fire up your PC
browser, and you’re ready to catch the wave.
Admittedly,
the interface isn’t much to write home about—no eye-candy,
JPEGs, or multimedia. Just remember that it’s not about
what the web page looks like, but rather that it came
from a plain ’51 talking to a standard browser.
The
example does demonstrate the ability to accept input
to a browser form and use it to control the ’51 (i.e.,
set LEDs and display a message on a plug-in LCD). However,
it does not demonstrate the ability to shove data the
other way. A simple input device, even if it’s just
a DIP switch, added to the ’51 board and an upgraded
demo to show how to deliver dynamic data (not just a
static web page) help.
The
guts of the web server code are shown in Listing 1.
Interestingly, I found portions of the program consisted
of previously published open-source code. There’s nothing
wrong with that and it gave my confidence in the W3100
a bit of a boost. Formal verification, test suites,
and the like are nice, but running somebody else’s TCP/IP
software on the chip is also a valid and useful real-world
test.
| Listing
1—Thanks to the hardware assist from the W3100,
a simple web server boils down to a few pages of
C. |
AND
THE VERDICT IS
I
must say that after getting under the hood, I have mixed
feelings. There’s no doubt that the overall i2Chip package
and presentation is unpolished. The documentation isn’t
great, the demonstration software is a little awkward,
and I’m left with almost as many (but different) questions
as when I started.
To
be fair, i2Chip is a tiny overseas start-up (a subsidiary
of South Korea’s Wiznet). I’ll cut them some slack for
that reason, but the marketplace at large will be much
less forgiving. A good chip is necessary, but by no
means sufficient to guarantee business.
By
the same token, i2Chip deserves plenty of credit for
delivering a unique solution that has the appearance
of actually working. Competitors may hem and haw, but
nobody can ignore the fact that i2Chip has managed to
put a plain ’51 with a tiny bit of code (webserv.hex
is only 11 KB or so) on the ’Net. Pardon the pun, but
I’d say that stacks up well against the typical 32-bit
CPU and megs of memory solution that many others are
promulgating.
There
isn’t, and likely never will be, one single universal
embedded Internet solution. i2Chip alludes to a forthcoming
higher integration solution combining MCU, W3100, and
PHY on the same chip. I say bring it on and the more
the merrier.
Hardware?
Software? A little of both? For now, I’d say the answer
is: all of the above.
