Supported GPRS Modems?

Hi!

I just wanted to ask, if anyone of you has good experiences with serial modems in combination with the Embedded Master, EMX or FEZ Cobra boards.

We are searching for a simple GPRS modem connected via USB or RS232 port. (although we would prefer USB, was we need as much serial ports as we can have for periperals)

All I could find out so far, is that GHI uses the TELIT GM862 in its PPP class demo of the GHI SDK.

Of course it would be nice, if that modem would be still producted and is therefore affordable. (so no $130 a piece ;-))

Any suggestions are appreciated! :slight_smile:

Thanks
Do you have any suggestions?

That is exactly what I was just about to ask.

[quote](although we would prefer USB, was we need as much serial ports as we can have for periperals)
[/quote]

The FEZ boards have drivers for the FTDI USB<->RS232 converter chips so you can add on as many serial ports as you need. :slight_smile:

You mean adding an USB hub and then plugging in USB2Serial converters? Isn’t that grose?

[quote]You mean adding an USB hub and then plugging in USB2Serial converters? Isn’t that grose?
[/quote]

Well, it all depends on your application. If you need many more more serial ports then yes you need a hub. If you just need one serial port for a GPRS modem then it does not require a hub, just the converter chip. I have one made by Parallax that is only as big as the end of my thumb.

you mean that one, right?
http://www.parallax.com/tabid/768/ProductID/378/Default.aspx

Yep, that is it. I also have one of their USB2SER which is nice for doing serial debugging as the downstream side is TTL level.

Some of our customers are using UBLOX modems.

good morning Joe :wink:
I am sorry, but could could you be a little more precise?

I found some of them. Like the “LEON-G100, G200 GSM/GPRS standard grade 2G modules” which seems to be the cheapest one.
However - its product description says that it has an "embedded TCP/IP stack"
http://www.u-blox.com/en/wireless-modules/gsm-gprs-modules/leon-gsm-module-family.html

Do those customers use those modems together with the PPP stack of GHI Electronics, or do they use that embedded TCP/IP stack? I mean if the latter is the case, why would I need FEZ Cobra, EMX, Embedded Master, etc? I could as well use USBizi, right?

@ Jeff_blirt

If I would use a hub solution and add 2 or 3 of those pharallax converters, can I also use hardware handshaking then?

[quote]I am sorry, but could could you be a little more precise?
[/quote]

Since it is the same company so I guess you can deal with all the modems they make the same way.
I personally tried LEON-G200.

[quote]Do those customers use those modems together with the PPP stack of GHI Electronics, or do they use that embedded TCP/IP stack? I mean if the latter is the case, why would I need FEZ Cobra, EMX, Embedded Master, etc? I could as well use USBizi, right?
[/quote]

The internal TCP/IP stack of the modem is not used. It is used with GHI’s PPP and NETMF TCP/IP stack.