GSM module for transmitting further than XBee
Elkin
Posts: 58
Hello forum,
I am working with a propeller application where I have to transmit data from several remote sites and I would like all the data to be sent back to my location. In the past I have tried the XBees but even with the 28 mile range it wasn't enough. Because these are remote locations, like the middle of lakes or mountain streams, an internet connection won't work either. It seems like there are off the shelf GSM modules that have been used with arduino (which I am not using), however I thought these would work more or less the same as the AT code that the XBee was using.
Before I look into this more, it would be nice to know if there was any object or code that someone else has worked with and would like to share.
More specifics on the project: I am storing about 8 comma separated values per line at 5 lines per second (5Hz). Each file is 15 minutes long. My goal is to wake up the GSM module once per hour and have it send 4 of these files (which are stored on flash memory) at once back to my PC using hyper terminal or an email account or something like that.
any advice would be greatly appreciated!
I am working with a propeller application where I have to transmit data from several remote sites and I would like all the data to be sent back to my location. In the past I have tried the XBees but even with the 28 mile range it wasn't enough. Because these are remote locations, like the middle of lakes or mountain streams, an internet connection won't work either. It seems like there are off the shelf GSM modules that have been used with arduino (which I am not using), however I thought these would work more or less the same as the AT code that the XBee was using.
Before I look into this more, it would be nice to know if there was any object or code that someone else has worked with and would like to share.
More specifics on the project: I am storing about 8 comma separated values per line at 5 lines per second (5Hz). Each file is 15 minutes long. My goal is to wake up the GSM module once per hour and have it send 4 of these files (which are stored on flash memory) at once back to my PC using hyper terminal or an email account or something like that.
any advice would be greatly appreciated!
Comments
For the GSM modules, sure they should work with a Propeller if there is a match on voltage communication levels. You can check the OBEX if there is an object. For the GSM modules to work, you would of course need to ensure the location has mobile service. Would it? I've explored using GSM with a propeller, but haven't dove into it yet. The communication set would be different than the XBee, you couldn't unplug the XBee and plug in the GSM and expect it to work. Instead you would have to adjust code for the initialization and sending of messages and retrying for failures.
Another option, but certainly much more expensive, would be to use a satellite communication service. RockBlock (http://rockblock.rock7mobile.com/products-rockblock) would be such a device you could use. It would need a view of the sky to reach the satellite. The service can then be setup to e-mail you or you could use an API to gather the data from the service providers web site.
I'd recommend checking out Digi's site for some other long distance radios. They might not be embedded like an XBee, to get the distance you are wanting you may have to get a packages product that you then interface to with a RS-232.
At any VHF or above, the curvature of the earth will limit you to about 7 miles with antennas about 6' off the ground. No matter how much antenna or power you throw at it. (Except for lucky reflections from tall objects, dense clouds, airplanes, meteor trails, The moon, etc) Elevation is everything.
Yes, the range claims on the bubble pack GMRS radios is complete excrement of male bovine.
I have not actually used the GSM modules, but I see from the datasheet that they may be operated like a modem, using the simple AT command set. (Different from AT commands with Xbee). The cell towers you would be communicating with will handily solve the elevation problem.
I built a project a few years ago based on the prop and the SM5100B-D (GSM). The function of the project is simple... If the sensors attached to the prop detected something outside specific parameters, it would send an SMS (text message) to my bosses phone (including a few parameters, i.e. variables). Worked great. I purchased the GSM module from sparkfun. The main program is 8 pages (not including object files). I used "FullDuplexSerial" to communicate with the GSM module. The code is not "commented" very well. But if you are interested, I can dig up the code on my old computer and attach to this thread. Since the main object is rather lengthy, I will only send methods that you are interested in. Just let me know. The code is all in spin. Good luck.
You are correct.
Using some sort of GSM module has been on my todo list for a while now. I'd be interested in see the code.
Yes, But.... don't get yourself in trouble.. Anything I (we) can make of this that is successful will go to the OBEX, MIT license and all. If we have such contact, and then I (or any of us) accidentally re-invent something your company considers their IP, it could be hard to 'splain Loosey.
I'm kinda excited because this is the first project I've been interested in where this IP mess can't happen to me.
I'll buy a different one, maybe Adafruit's FONA. That way we can shoot for wider compatability. Have fun on your trip!
Gets really interesting about page 101.
The complexity of the standard is bewildering, but if we limit ourselves to simple SMS functions, leaving data formatting to the application, this could make for a very simple object.
There is an object posted in the forum.
I used SMS and they proved reliable and easy to send and receive.
I used a nmea style message, with fixed width to simplify the process.
Using internet connection was in my case difficult and unreliable.
Nice thing is SMS work easily also in roaming.
Massimo
http://forums.parallax.com/showthread.php/149716-SIM-900-GSM-module-interface-object-WIP
Thanks for watching out for your fellow developer though.
This is definitely becoming an interesting project and it is quite obvious that this is something that more than just myself is interested in.
After all of your comments I ended up deciding to go with a Telit Multitech MTSMC-EV3-MI-IM-N3 from semiconductor store. It is an easy install with the prop and the spin code was very kindly donated to me.The modules can operate on either serial or USB and can do anything form sending a simple text message to opening a full blown TCP/IP connection.
Bobb Fwed and NAVFAC10, I am going to guess that these are not that different from your application (also using the verizon network), and probably have the same capabilities and features. I have ordered the modules and wench they get here (about 3-4 weeks) I would be interested in talking about this a little more with you over PM.
If anyone would like more info about the modules that I went with, I'd be happy to share. In addition, I will talk to the person that has the code and see if that would be interested in posting it on here or on OBEX.
Will post more when I have some updates.
Very well. I'm very interested in seeing what you've got!
I've been writing some methods based on everything posted here, and on the tutorials from Sparkfun and Adafruit. I've been concentrating on receiving and sending text messages, and I think my code will work with all of the modules mentioned in this thread. I'll post what I've got as soon as I get it presentable. (I don't have any hardware in hand right now.)
NAVFAC: Thanks for the heads up on the current spike!