Shop OBEX P1 Docs P2 Docs Learn Events
Using Basic Stamp And GPS Module to Wirelessly Send data to a Web Service — Parallax Forums

Using Basic Stamp And GPS Module to Wirelessly Send data to a Web Service

AndyMenonAndyMenon Posts: 26
edited 2013-04-13 10:03 in Accessories
Hello Folks,

I plan to build a simple GPS tracking device using either the Basic Stamp GPS Module (or the Flora GPS Starter Pack).

The question is , would it be possible for the Basic Stamp module to wirelessly communicate to a website over the internet?

The Web site would consume the co-ordinates and draw them on a map.

Any pointers would be really appreciated!

Thanks,
Andy

Comments

  • Mike GreenMike Green Posts: 23,101
    edited 2013-04-11 20:11
    A Basic Stamp by itself has no means to communicate over the internet. You'd need to use some kind of interface unit for that. A lot depends on what the other website needs and how it expects the information to be communicated. Solutions include the PINK from Netburner, This is not wireless, but you could use a wireless bridge with it. You could also use a Roving Networks RN-XV module mounted on one of Parallax's adapter boards for the xBee (like this). This would allow your system to send serial information via a Telnet connection to your website. It could also send and receive packets using the GET and PUT webserver commands.
  • AndyMenonAndyMenon Posts: 26
    edited 2013-04-12 20:30
    Thanks Mike!
    I will be building this website. It will accept the LAT and LONG co-ordinates and would put out a page with the co-ordinates of the object being tracked.
    That is the easiest part as far as I know.
    The biggest issue is, if this object is out in the open world, would any of these components you've recommended help achieve the functionality?

    Thanks again!
    Andy
  • Mike GreenMike Green Posts: 23,101
    edited 2013-04-12 20:44
    It all depends on the details that you haven't shared. For example, what sort of wireless range are you talking about? The PINK is actually a webserver. Would that work for what you want? Note that you could use some kind of wireless serial link between the Stamp and the PINK like xBee modules or, as mentioned, you could use a WiFi bridge. Do you have a wired internet connection or only access to WiFi?
  • AndyMenonAndyMenon Posts: 26
    edited 2013-04-13 06:32
    The intent was not to keep anything secret. I didn't want to make this a conversation about custom cars and hot rods. :smile:

    The application is real simple in concept. I am having a custom car in my garage that I am trying to secure. Not that it would be stolen from my garage, but from a place that I would park anywhere in and around town (and also from my teenage son). So the wireless range is the size of a metro (to begin with).

    The website would not be on the on-board web server, but would be hosted on my commercial web hosting space that I already have and use to run some of my trial IT projects. Therefore, the on-board device would need to communicate to this website via a wireless channel and send a message if the car has been started without an RFID key-ring. In parallel, an SMS would go out to my cell phone notifying me to track my car by looking up my website.

    Obviously, there are lot of tracking devices out there that are enormously expensive and charge a monthly fee and therefore I'm trying to build something for two reasons, one being to not pay those monthly fees, and the other to revive a long lost electronics hobby.


    Thanks,
    Andy
  • Mike GreenMike Green Posts: 23,101
    edited 2013-04-13 07:12
    The only way you're going to be able to do this is to use a cellular phone module (like this one). You'll need a data plan like those for a tablet like the iPad or you could use SMS.

    The 900MHz xBee modules don't quite have the range you want. The numbers quoted in the documentation are ideal ranges with good antennas. You're not likely to get anything like that in realistic conditions. There are higher power 900MHz devices available, but they cost more.

    You won't get the coverage you want with anything else that's legal unless you want to get an amateur radio license. I don't remember the rules for an automatic remote controlled station, but I think you could do what you want that way. It wouldn't be cheap though. Two good walkie talkies plus a decent antenna at the base station ... you're talking about a few hundreds of $$$
  • AndyMenonAndyMenon Posts: 26
    edited 2013-04-13 08:08
    Hmmm.. in the meantime I found something else on the Parallax site here . The details for this demo project lead to a different page located here.

    I was wondering if this could help me simplify the solution like so:

    Unless there is some kind of limitation in the size of the message that I am currently unaware of, the GSM module (Siemens TC35) module could synthesize a web URL and send it as an SMS to my phone every 10 seconds or so (this time could be made variable). A URL that would look like:

    http://www.mywebsite.com/lattitude/longitude/ . Even simpler would be to send a link to Google or Bing maps.

    I may have to click on the URL in the SMS message each time I get it to get an updated position on my car.

    Obviously, it would suck to keep clicking on an SMS text message repeatedly, but it is not everyday that your car gets stolen.

    Thoughts?
  • Mike GreenMike Green Posts: 23,101
    edited 2013-04-13 08:38
    Good hunting! There's nothing like a worked and tested example.

    The SMS size limitation is 160 characters. That shouldn't be a problem. I like the idea of sending a complete URL for a Google or Bing map lookup.

    One thing you'll have to be careful of is power drain. I don't know what the standby current drain of the Siemens module is, but the one I showed a link for is about 2mA. I have no idea what the Garmin GPS module draws in standby. If you have more than a few mA of standby drain, your monitoring unit can run down your battery. Remember that it's on all the time. That's 100 hours every 4 days, almost 800 hours a month, and your battery may only have a 40AH capacity (typically 40AH to 70AH according to the Wikipedia).
  • AndyMenonAndyMenon Posts: 26
    edited 2013-04-13 09:24
    I can't agree with you any less. I think this might just work!
    But what is missing from that article is to connect the 12V from the car's ignition to the 5V on the BS2. I think the easiest way to do this is to add a 12V to 5V step down switching regulator and a 10K resistor to one of the IO pins.

    As for the batteries, I may have to have a set of rechargeable battery packs that I could hook up the tracking device. The batteries could hook up to an on-board battery charger that runs off of the cigarette lighter terminal (which by the way I have already set up to charge my cell phone) when the car is running. This should be sufficient when I drive out and park. And when the car is garaged, I could hook up the battery pack to 12V in the wall.

    I already have a similar set up for my regular car battery. It's been wired to a trickle charger all winter long, and I check the battery voltage from time to time to make sure that it is maintained at or over 12.6 V.

    Thanks so much for your patience! Just started out with Electronics after a good 20 years, and feel extremely rusted and outdated.

    Andy
  • Mike GreenMike Green Posts: 23,101
    edited 2013-04-13 10:03
    You can build your own 12V to 5V switching regulator based on the various datasheets and application notes from the chip manufacturers or you can buy a ready made one like those from Dimension Engineering. Check the peak current drain of the cellphone module. They can draw quite a bit of current when transmitting.
Sign In or Register to comment.