Ethernet connectivity « Jee Labs Talk

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Ethernet connectivity

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Jean-Claude
Key Master

Ok, so there've been several comments about adding Ethernet to JeeNodes.

My question is: what do those people who would like to see this happen look for, exactly?

Ethernet on an 8-bit memory-limited MPU is quite a stretch. The WizNet module takes over some of that burden, but there is still *very* limited room for page content (let alone templating and filling in values). What about DHCP, for example?

There are a couple of ways to go with this, I think:
* low-end ENC29J60 or similar
* Arduino-like WizNet module
* SLIP, i.e. use USB/serial to get to a computer which does real Ethernet
* hook it up to a low-cost Linux card w/ ethernet

All but the last lead to solutions which push the limits of what a JeeNode can handle by itself.

I would think that absolute rock-bottom cost need not be the main criterium here: the usual scenario will be a bunch of JeeNodes, with one central node needing an Ethernet hookup. That's why I added the embedded-Linux option in the list above (I can probably get a pretty decent webserver going with JeeMon, even on very small Linux cards).

And then there are other questions: what should the result do? Serve some very crude text/html pages? Fancy web interface? Something in between? Act as web client and push results to another TCP/IP server? Broadcast incoming data over UDP?

Soooo.. if you consider ethernet an important missing feature, could you please describe the main usage scenario you're looking for?

Posted 6 months ago #
weylan
Member

The hard part ensues....

I think that the key pieces might be:
jeenode to ethernet interface so you can get data from the jeenode to ethernet. Currently the arduino shield alone is like $45. Do we need something that full featured?

This means some kind of interface to rj45 and TCP minimalistly.

DHCP if we could but fixed ip is fine.
Ability to publish pages of data, but the ability to push data to another ip would be just as useful if not more so.
Fancy web interface, I don't think so, but the ability to be able to be polled for data directly would be a great feature for diagnosing things.

The whole thing revolves around making a wireless network. ability to interface back into the lan so we can monitor it, via a more powerful machine, but ability to get by or test or diagnose things or even run them in a low power mode for all the devices with out a computer if possible.

Posted 6 months ago #
s.mihai
Member

i think it has to be something simple and cheap (so that it is accesable)
-static ip
-ability to publish webpages of data (display different variables on a webpage so that you can then easily parse them from a server whatever way you can, but also do a simple debugging by viewing the data the node is displaying
-ability to be controller by ... i don't know... GET commands, or POST ones

Posted 6 months ago #
matajumotors
Member

I also think no need for DHCP

-static ip
-simple web with decoded and raw data (maby little log)
-ability to push data to other server
-some password or else autentification
-ability to send commands to node(s)(or TELNET?)

Posted 5 months ago #
loomi
Member

Hi,

I'm looking for a really simple network interface to the JN's too. For my needs it would be enough to go with the enc28j60. Especially because there are already some schematics and also code available:
- http://tuxgraphics.org/electronics/200606/article06061.shtml
- http://www.nuelectronics.com/estore/index.php?main_page=project_eth
- http://blog.thiseldo.co.uk/?p=344
- (http://members.home.nl/bzijlstra/software/examples/enc28j60.htm)

The third link shows that it is possible to use the enc28j60 for monitoring purposes. And it is at this time one of the cheapest possibilities.

I see one tricky part: To control the enc28j60 in parallel with the rfm12b over one SPI bus.

If the basics once work, I think even higher level protocols are feasible (http://gkaindl.com/software/arduino-ethernet/). Think of the Bonjour/Zeroconf protocol. Seconds after you connect the JeeGate(?) to the network it shows automatically up on your computer.

Posted 5 months ago #
andras
Member

All requirements mentioned above except DHCP and telnet can be fullfilled with the enc28j60+tuxgraphics library (see also my posts here: http://talk.jeelabs.net/topic/102/page/2 ).

Having Jeenodes+ether relaying RF12 messages with http as a RF12 gateway (lik a range-extender either on the LAN or WAN scale) would be sufficient for me. So I would also prefer the low-end enc28j60 solution. For anything more, one can still use the linux board solutions.

I made a sketch (arduino+enc28j60 ethershield) reading electricity meter IR pulses that sends them to my server with http GET variables. It works great and occupies about 10K space. The library allows for further space-saving by disabling parts that you don't want to use (udp for instance). So there's enough room to also accomodate the RF12 library.

Posted 5 months ago #

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