I would like to send & receive very basic telnet commands with a pic or send per
iodic SMTP messages to my mail server, whichever is easier. I'm wanting to deliv
er temperature readings from a remote location in the mountains down to a contro
l center 90 miles away which has a wireless ethernet link with the site (soon to
buried in the snow). The only interface available is a standard ethernet hub, e
ither 10Base-2 (coax) or 10Base-T (UTP). Prefer the UTP, and (wishful thinking h
ere) a 16F84. I ass-u-me I will need another devce to make the actual PIC-UTP in
terface, but that only gets me so far. I still need to properly encapsulate the
packets, etc. Asking too much? Tutorials out there? I may just put a cheap-o Lin
ux server up there and read the printer port if this isn't going to happen.
FWIW, I am familiar with SMTP and telnet protocols, and have a pretty good grasp
of networking issues, but it's always been with off the shelf hardware in PCs o
r other related networking devices.
TIA - Fred
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> I would like to send & receive very basic telnet commands with
> a pic or send periodic SMTP messages to my mail server
> I'm wanting to deliver temperature readings from a remote location
> in the mountains down to a control center 90 miles away which has
> a wireless ethernet link with the site (soon to buried in the snow).
> The only interface available is a standard ethernet hub, either
> 10Base-2 (coax) or 10Base-T (UTP).
> I may just put a cheap-o Linux server up there
Frankly, for a one-off project, the non-recurring engineering to
build all the layers of networking stack (Ethernet, IP, TCP, and
Telnet or SMTP) just isn't worth it. I'd go with the Linux box.
If you want to do it with an embedded processor, I wouldn't use
a low-end PIC. The Motorola 32-bit line have some with built-in
serial hardware that can do Ethernet (e.g. 68360).
At the risk of sounding like a Scenix salesperson, you might want to check
out their website. They're releasing code for a full TCP/IP stack, with HTML
or SMTP support on top, for their SX48/52 processors. These are pretty much
PIC compatible, but *much* faster, and, I believe, cheaper.
The code as it stands (I believe) is intended to connect to a modem via a
PPP through software UART. I don't know how much effort it would be to add
support for an ethernet controller (eg. the 8-bit CSxxxxx-whatever it's
Alternatively, as Lee says, if you have control over the server, there's no
point doing a full TCP/IP implementation... you may as well write a UDP/IP
datagram based system. An order of magnitude less complex.
>I would like to send & receive very basic telnet commands with a pic or send pe
riodic SMTP messages to my mail server, whichever is easier. I'm wanting to deli
ver temperature readings from a remote location in the mountains down to a contr
ol center 90 miles away which has a wireless ethernet link with the site (soon t
o buried in the snow). The only interface available is a standard ethernet hub,
either 10Base-2 (coax) or 10Base-T (UTP). Prefer the
The latest EDN mag shows a chip called the iChip S7600A which
implements the TCP/IP protocol in hardware. Suposedly connects
pretty eaisly to a x86 or 68000 system. It might be a lot of work to
interface to a PIC but it's got to be eaiser than rolling your own.
> have you thought about a network print server box? You can get these for a
> few hundred and they come with Centronics port (and sometimes serial as
> ----- Original Message -----
> From: <firewall_fredKILLspamHUSHMAIL.COM>
> To: <.....PICLISTKILLspam.....MITVMA.MIT.EDU>
> Sent: 13 October 1999 19:54
> Subject: Telnet/SMTP/Ethernet, Possible?
> > I would like to send & receive very basic telnet commands with a pic or
> send periodic SMTP messages to my mail server, whichever is easier.
I don't know how easy you could make a JetDirect work like that. Our
HP LaserJet IIIsi has a jetdirect card in it. It's designed to
receive data from the ethernet and then send it to the printer while
also acting as a queue. Although it has the ability to query the
printer for status info you would have to know the protocol used
unless you wanted to do more than send Online/Offline messages. I
imagine the protocol is documented somewhere though.
That would be an internal Jetdirect module. We have them in a couple of HP
Lasers. We also have the external Jetdirect boxes. I'm not sure they are
just routing the parallel port over ethernet, but might actually using a
printer specific protocol. But I could be wrong. The reason I would suggest
it's not generic is as Richard says, you configure the method of Print
serving, such as queue based (it polls a Novell server for jobs). You must
also set the print language used by the printer but this might just be for
test\configuration pages. Either way, if you can get your device to act as a
generic printer byou should be fine, but I wouldn't be surprised if you
couldn't find protocol docs as this is all done by the JetDirect software,
it handles mapping an IP address (or NetBEUI or IPX) to a printer port.
I would suggest a router with a SLIP port mioght be a better bet as this is
a common method of internet connectivity. You should be able to pick up an
old BNC router with slip pretty cheaply. Alternatively, AUI uses a 15 (I
think) pin DB style connector but I have no idea as to what protocol it
uses. But, AUI->BNC\RJ-45 (and vice versa) transcievers were quite common
(harder to find now and often quite expensive new) so you could prob. pick
one up cheap.
There's been a lot of controversy over whether this site works at all.
Assuming it is true to it's word there are the following issues\problems:
1) Uses a SLIP (Serial Line Interface Protocol) link to a router.
2) Appears to use Port numbers alot in it's web handling (doesn't effect
3) Claims to have a telnet server running but whenever I try to connect it
just times out.
Even if you could get source I would suggest the Scenix SX Stack would be
better as general software.