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Have anyone tried PPP on FEZ Cobra to connect to internet through modem?


#1

PPP is very important and nice feature that have been added exclusively to GHI’s EMX and ChipworkX. With this feature you can communicate with WAN using V.90/GPRS/3G modem or any serial port based modem.

Example #1: You have your cobra in a site with only a land telephone line and you want to send back some information to your server in another site.
All you need is:

  1. A PC with dialup modem, (set it up as a terminal server).
  2. FEZ Cobra connected to a dialup modem ( I am sure most of you have one of that old fashion modems with COM port). Don forget to add RS232 converter at the FEZ Cobra serial port before you connect the modem.
    Note: PPP is supported with USB-to-Serial if you like to connect to FEZ Cobra’s USB host port.

Example#2: You would like to have a twitter account for your car and you want it to tweet its position every 5 minutes. This is Freakn’ Easy with FEZ Cobra.
All you need is:

  1. FEZ Cobra connected through serial port to GPRS modem such as telit modem:
    http://www.sparkfun.com/commerce/product_info.php?products_id=9297
  2. a GPS extension to get the coordinates
    http://www.tinyclr.com/hardware/12/fez-cobra/#/grid/item/24/
  3. Sim card with data plan.

With few line of code you can let FEZ Cobra dial-up and connect to the public network using PPP and get access. From this point you can open/close sockets the way you like.

If anyone is interested in making a cool project using PPP, I am here to help.

This is an old video showing a simple example we did before using Embedded Master Development System


#2

Do you have any example code?

Can the host port on the Cobra access virtual serial ports, ie a 3G USB modem? I would also need a way to switch the mode on the device from mass storage to modem, as it comes with a mountable volume with drivers.


#3

There is an example code under the PPP class in the GHI libraries documentation.

We supported SierraUSB modem (used with AT&T) before. in V3.0. But we dropped the support because we did not see a lot of interest from users and there is not USB standard class for those modems.


#4

Ive read this post about 5 times and I also wanted to connect to the outside world with 3G
The USB modem you speak of from AT&T if you connect via this device… what is the data speed?

I want to report (on a simple web server) about twenty varables to any one with access.

If you have followed my conversations on this forum you will know I’m in the crane industry and this could be a very valuable to our customers interests.


#5

Take aloon at this thread. Patrick5 already could get his verison USB modem working with FEZ Cobra. I think You can use AT&T USB modem working the same way. I can help you in accopmlishing that.

http://www.tinyclr.com/forum/10/1071/#/2/

[quote]The USB modem you speak of from AT&T if you connect via this device… what is the data speed?
[/quote]
To be honest with you we did not test the data speed that you could get with sucj modem. But I suppose it depends on the baudrate you set mainly and on the signal strength. And I think it should be less than 1MByte per second, since this is the throughput attained using Ethernet on EMX.

[quote]I want to report (on a simple web server) about twenty varables to any one with access.
[/quote]
I think this can be done very easily with FEZ Cobra.


#6

[quote]ve read this post about 5 times and I also wanted to connect to the outside world with 3G
The USB modem you speak of from AT&T if you connect via this device… what is the data speed?

I want to report (on a simple web server) about twenty varables to any one with access.

If you have followed my conversations on this forum you will know I’m in the crane industry and this could be a very valuable to our customers interests.[/quote]

Interesting application… I’m sure you could easily interface with existing wind instruments, or stick your own NMEA2000 at the top and get real-time wind readouts… could save a lot of time/money in the future! Could obviously combine this with imaging, readouts from strain gauges/inclinometers/etc to give a very interesting view of the status and safety.

The 3G modems are pretty fast, you’ll have no “load” issues. My particular carrier/network combination does not appear to allow for incoming connections, so I’m making a connection to a remote server to act as a proxy.

Best way to implement would probably be to have a remote server to act as this proxy, serving static files like the images/JavaScript/etc associated with the page, and using the device only for sending parameter updates. This is not because the device couldn’t do it, it could, but it’ll be less latent and simplify some things.

Linux’s “wv_dial” and “usb_modeswitch” references for your particular device are what you need to get things started.

Also, just a hint - I don’t want to start a carrier war (as I feel they’re [italic]all[/italic] awful), but I have AT&T phone service but have to have Verizon data service because their 3G data coverage is MUCH better in rural areas. If the crane never leaves a big city, you’ll be fine, but if it’s operating in more remote areas, there are better carriers.


#7

I have the required USB SetupCommands to turn to switch to modem mode of the sierra modem (AT&T 3G stick). I think if you took Patrick’s code and added the setup commands then you can get working easily.


#8

Also I think, at the application layer, you can make a simple application on FEZ Cobra that send s the parameter you need to know periodically to your Server. Then you can query the latest data from your server with time stamps


#9

I’ll do a bit of research… as you know the um175 is used in America by verizon and a few others, I’m sure I can find one simular here in the UK .

I’ll let you know as soon as I get one


#10

Hi,

I also looking for a solution to connect to internet via 3G from my EMX module, is there a working solution around.

I use a industrial pc and a USB stick, which is supported by Windows XP which runs at that machine. I want to replace the industtial pc by an EMX module, but I need some solution to implement the communication.

Thanks for pointing out, whats around here.

With best regards

Gerhard


#11

In this thread patrick could use a USB modem to access the internet using EMX
http://www.tinyclr.com/forum/10/1071/

In this case Patric’s modem runs as a CDC device (USB2serial).I am not sure about your modem.

You can always use a serial 3G/GPRS modem such as Telit modems instead.