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Ethernet to serial module?

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I'm kicking around another project idea and thought I'd expose it to the collective to see what y'all think of it.


What would you think of an ethernet to serial interface?


It seems a bit mundane but it would be a module that just works. You could feed it either TTL or RS232. Or, it may have a pluggable interface where you could slap on your own device that just needs a serial port ie: GPS or Zigbee radio.


Personally, I was thinking about two applications.


The first is for my Linux server. I'm usually annoyed when I have to remotely reboot my server after software upgrades ie: kernel updates. When I do reboot the server, my NX client/server connection is severed when the service is shutdown and then I can't watch the console messages. So, I want to redirect the root console to /dev/ttys1 so that I always have control over the box. I would connect the S2E module directly to the serial port and then I'd telnet into the S2E box from my workstation. This way I could watch /var/log/dmesg scroll up the screen when I reboot the server remotely.


The second idea: I don't want to pay Digi a bar of gold for their ConnectPort X2 so, I was thinking of plugging one of my Digi Zigbee radios into the S2E so that I could have an inexpensive network bridge to a Zigbee network.


Nevertheless, once you make an S2E you could apply it to almost any project.


So, what do y'all think?

Does the idea have merit or utility?

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I was looking at some E2S modules for my Ethernet to X-10 project (as an alternative to INSTEON's EZSrve,) and so far the two top contenders are WIZnet's WIZ830MJ and WIZ811MJ. The only negative about 830 is the lack of SPI.

Other option is something based on ENC28J60.

It would be nice if we all got the same thing so we could share the code.


Is this what you were thinking about or do you want to use LP for that?

I was researching that few months back, but you cannot implement TCP/IP stack on 2231.

Now, with the arrival of 2553, I am thinking this may be an option.

If I remember correctly, I found some TCP/IP code for MSP430, so it could be just a matter of adopting it to 2553.

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I was actually thinking of making the Stellaris LM3S6432 to do the heavy lifting of E2S since there's a mature reference design for it.


The reference design has a built in webserver and telnet service and the source code and design files are available. So, you could customize the firmware to your needs. You might even be able to modify the webserver code for your needs.


Yes, all three of those modules are similar to my idea. Only, I was thinking of just presenting a serial port to the data source. I suppose you could present an SPI or I2S interface if the code and hardware were modified accordingly.


The most important feature would be the control over the hardware and software design. We could do anything we wanted to it (within reason).

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Serial to Ethernet links are quite common in the petro industry IE gas stations, If you are looking for an a quick tear down and pics, I have a few DigiPorts 4 port serial with WIFI or one port serial. they can be switched to rs232 or rs485 and have built in web interface. personally i havent touched them because of the resale value (retail 300 and 800+) only tested them to make sure they work.


So i am willing to donate the single port for hacking or tearing both down for a fun and educational experience.

also im willing to sell one of them for dirt cheap if need be with driver disk.

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A pictorial tear-down of a digi unit would be an interesting and educational read. I'm wondering what processor Digi uses inside their products.


I remember their ConnectPort X2 being expensive so it would be cool to have an alternative to it.


I also never thought of making the device RS232/RS485 configurable. I guess my mind wasn't in the industrial context.


Right now, my design context is to create a pluggable module that you might find at Sparkfun or Adafruit.


The Stellaris RDK-S2E is a great unit but it has zero hardware configurability. That is, it does one thing only. I would like to expand it so that it be even more useful in our experiments.

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Ah Nuts! I just remembered about the MAC address stuff.


If a person is going to create a device that has ethernet then you have to get your own MAC address block. That costs moolah.


The IEEE are the people in control of this. I think this is the proper link for the details.

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As long as your not Implementing your Own Ethernet HW you shouldn't have to get a MAC address Block, this should be taken care of the port vendor. I know Wiznet and other TCP on a chip vendors already have MAC addresses for there devices.


When i get home today i will take some Pics on the Digi ports and Post them here and i will try to get as many of the chip markings that i can off of those.

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This is a DIgi One SP by Digi- 1 Port serial to Ethernet bridge/port server

rs232 or rs422/485 full duplex or rs485 half duplex -- user selectable with switches

optional termination resistor -- user selectable with switches

input voltage 9v-30v .37A-11A

pic1 http://justinstech.org/wp-content/uploads/2011/05/DSCN0619.jpg

pic2 http://justinstech.org/wp-content/uploads/2011/05/DSCN0624.jpg

pic3 http://justinstech.org/wp-content/uploads/2011/05/DSCN0625.jpg

pic4 http://justinstech.org/wp-content/uploads/2011/05/DSCN0622.jpg

pic5 http://justinstech.org/wp-content/uploads/2011/05/DSCN0626.jpg

sry please be patient, the pictures are quite large. if you want a better picture of something on the board let me know.



there is a Coldfire XCF5272VF, a max3243, 2x max 3491 an intel lxt972alc, AMD l320d890v1, 2675 voltage regulator, dg202b, an unknown memory chip, also some Ethernet hardware.


interestingly there are 2 rows of headers one 6 pin and one 4 pin, no markings on what they are for. I will go more into detail when i have some more free time.

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I received my Stellaris S2E kit today. It's a neat little device.


The serial interface board is kinda weird but I understand why they stacked it up that way. The USB cable is there to supply power to the target board. Sneaky.


I like the little webserver on-board. It's slow but it's there so that you can configure the communication parameters.


The telnet interface is cool. Telnet to x.x.x.x:23 for port1 and x.x.x.x:26 for port2. You've gotta have a terminal connected to the DB9 serial port connector to perform end to end testing.


I see this as a reference design device. It should be adapted to your application - whatever that might be.


I can see this being successfully adapted as an LP shield board. It would need a complete board respin and some new code created.


I can also see this ref design being successfully adapted as an ethernet to Zigbee link board. Again, a new board would be created to accommodate a Digi board and the code could be modified to be able to configure the Digi module.


I'm going to keep playing with this module. I may even get a second one so that I can try a long S2E2S link configuration.


All in all, I think it's a 9 out of 10 on the Nerdy Cool Scale


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I should also point out a small but important detail about this S2E kit.


There are two S2E kits on the TI/Stellaris: RDK-S2E and MDK-S2E.


The RDK-S2E kit is normally ~$150.

The MDL-S2E kit is normally $50.


The RDK is on special for $50 until the end of May.


The difference is all the extra stuff you get with the RDK. Take a look at the photos at the above links to see what I mean.


So, this is why this deal is a good one - the extras.

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