Shop OBEX P1 Docs P2 Docs Learn Events
Stamp use with cell phone and SMS — Parallax Forums

Stamp use with cell phone and SMS

stamptrolstamptrol Posts: 1,731
edited 2006-06-05 13:23 in General Discussion
·I have a data gathering/alarming application where the stamp will be at a remote location watching over some equipment. I have commercial power there but not always a land-line phone line.

· Has anyone had direct experience with getting the stamp to use a cell phone to send text messages? The idea would be for the stamp to initiate one or more short messages to the phone of the tech on call when a serious alarm occurs.

· The problem can be solved technically in several ways (wireless to someplace where there is a landline, getting Internet into the remote site, satellite Internet, etc) but cost is a real constraint and the cell providers have lots of promos going on where I can get cell phones and message service at a very low cost.

· Thanks for thinking this over.

· Tom Sisk
··

Comments

  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2006-05-17 14:22
    Tom,

    ·· I have thought of this myself in the past.· It's kind of like with digital cameras...Early on it seemed to be easy to communicate and control them from a BASIC Stamp and there were published protocols...Now it seems everyone has their own proprietary way to do this.· I guess you would need to use a phone that had a serial interface that the Stamp could talk to, so I guess the real starting question is does anyone know of such a phone that can still be used on current networks?

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Chris Savage
    Parallax Tech Support
    csavage@parallax.com
  • stamptrolstamptrol Posts: 1,731
    edited 2006-05-17 14:58
    Hi Chris,

    Thanks for info. I've been pulling in information and have found a couple of possibilities that are dealing with the proprietary issues you mentioned.
    I've got a Samsung camera phone which I will "draft into service" to try some of these things. Will keep you informed.

    Tom
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2006-05-17 15:02
    Tom,

    ·· Definately let us know what you find...If time permits soon I will be doing a Google search to try and narrow down such things myself.· It happens that I have a Motorola phone with service that doesn't get used at all.· It would be perfect for such a project if I knew how to communicate with it.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Chris Savage
    Parallax Tech Support
    csavage@parallax.com
  • Paul BakerPaul Baker Posts: 6,351
    edited 2006-05-17 15:02
    Well, yes sorta. Sparkfun has several cellular modules: http://www.sparkfun.com/commerce/categories.php?cPath=66_68
    and several eval boards for the modules: http://www.sparkfun.com/commerce/categories.php?cPath=66_69
    nice thing is they are designed to be interfaced in the manner desired, so the info should be easier to aquire.

    Just be sure to get a phone from the provider which has a SIM card in it, or perhaps you can just get a SIM card in lieu of the free phone deal.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    1+1=10
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2006-05-17 15:56
    Paul,

    ·· I wasn't aware of these...At least not that they could be set up on standard Cel-Service.· I had heard of GSM Modems and was looking into those.· I will do a little more research.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Chris Savage
    Parallax Tech Support
    csavage@parallax.com
  • Paul BakerPaul Baker Posts: 6,351
    edited 2006-05-17 16:00
    They are compatible with any carrier that supports SIM cards (AT&T, cingular, T-Mobil).

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    1+1=10
  • steve_bsteve_b Posts: 1,563
    edited 2006-05-17 16:11
    Although these guys are expensive, they are pretty darned reliable.
    We use Campbell's equipment across the country and in many place we have to use cell and sat comms.

    Anyhow, check'em out here!
    http://www.campbellsci.com/telephone

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    ·

    Steve

    "Inside each and every one of us is our one, true authentic swing. Something we was born with. Something that's ours and ours alone. Something that can't be learned... something that's got to be remembered."
  • stamptrolstamptrol Posts: 1,731
    edited 2006-05-17 16:46
    Thanks for the responses.

    So far, I think the attached site is getting close to what will work.

    www.riccibitti.com/tinyplanet/tiny_article.htm

    I'm pretty sure the micro shown can be "upgraded" to a stamp!

    Cheers
  • FlyingFishFingerFlyingFishFinger Posts: 461
    edited 2006-05-17 23:33
    My Dad had a Motorola TimePort...came with an RS232 connector cable, which would have been perfect....unfortunately, he got rid of it a year ago before I understood enough Stamping to attempt an interface (I'm 15).
    But it looks like that might be a good candidate for the job
    Rafael
  • ktekxktekx Posts: 71
    edited 2006-05-24 08:54
    I have had luck interfacing a Stamp to a Sony Ericsson using a prepaid SIM card which is relatively cheap and no contracts necessary. These cell phones have simliar AT command sets between models as well as being pretty inexpensive (or maybe even free, people are getting rid of these phones all the time when they renew contracts, their service provider offer free new phones).

    Here's my GPS tracker using SMS:
    s95417013.onlinehome.us/ktekx/3.htm
  • Tricky NekroTricky Nekro Posts: 218
    edited 2006-05-25 20:28
    I know a guy that has done this project with a motorolla controller I think... He used a card reader for the SIM and a kinda of transmiter...

    The controller would· easily·be replaced by a stamp... I don't have the schematics, not the closest relationship this him so that I persuade him to upload the schematics...





    At least, it's possible...

    Provas, Greece

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    -Rule your Destiny-
    --Be Good. Be Bad. Be Provas--
  • John BondJohn Bond Posts: 369
    edited 2006-05-29 13:23
    Hi Tom

    We did some work with a Siemens Industrial Cellphone unit about a year ago.

    1. The cellphone unit used the standard Modem AT commands
    2. The text input from a Stamp BS2p works fine
    3.·The SMS text out from the cellphone is not buffered and flow control and RTS/CTS doesn't work

    We played round with the SX28 UART buffer but ended up using a PC

    in addition, the pins on the cellphone were wired incorrectly. A truly frustrating project!

    The unit we used isn't on the market any more but, as security (protection against murder, rape·and robbery) is such big business in South Africa, there are dozens of other similar units here being linked to PICs PCs and even PLCs.

    Just make sure the unit has that buffer on the ASCII output.

    Good luck from Kwa Dukuza


    John Bond

    ·
  • stamptrolstamptrol Posts: 1,731
    edited 2006-05-30 16:47
    Hi folks,

    Keep all those tips and reports coming! I've ordered some cables, etc for my Samsung phone and will be descending into the belly of the beast shortly. Will report if I survive!

    Tom Sisk
  • stamptrolstamptrol Posts: 1,731
    edited 2006-06-01 23:42
    Some answers, some questions

    I got the cable for my Samsung cell phone and tested it with Hyperterminal on a PC. With the included USB drivers, I was able use the phone as a modem and dial out, etc. It appears that I may not be able to access the messaging registers with this particular phone.

    However, for my remote monitoring project, just having a wireless dialup modem may give a suitable and secure system.

    The Samsung cable is, of course, USB on the computer end so I need to convert it back to RS-232 for the Stamp to use. I have a Parallax USB - RS232 converter module, which is normally powered from the PC's USB port. Its USB connector is male and won't mate directly with the cell phone's USB plug.

    Has anyone seen/used an adaptor that has external power and has the USB end as female (that is, the same as would be found on a PC or laptop)? I checked with the cable plugged in the phone and the USB power leads are dead.

    Thanks
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2006-06-02 00:00
    Stamptrol,

    ·· If the phone is USB you may not have any connection options for a BASIC Stamp.· The USB to Serial adapters only work one-way in terms of conversion.· They will give you a serial port from a USB Port, but not the other way around.· Is there any chance of accessing the phone internally where there is most likely some TTL level serial interface?· I don't know anything about this phone, but maybe someone has hacked it on the internet somewhere?

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Chris Savage
    Parallax Tech Support
    csavage@parallax.com
  • stamptrolstamptrol Posts: 1,731
    edited 2006-06-02 00:30
    Thanks Chris,

    Just been looking at the USB specs.

    What I need is to make a USB socket connection from an existing RS-232 port. Sort of like having a laptop with an existing serial port but no USB port. As usual, I'm looking for pretty much the oposite of what is commonly available!

    I haven't ruled out cutting into the boss's phone, but was hoping to be able to go with off-the-shelf solution as much as possible.

    Cheers,

    Tom Sisk
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2006-06-02 03:51
    Tom,

    ·· It will be interesting to see what you come up with.· Please post what you find.· Take care.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Chris Savage
    Parallax Tech Support
    csavage@parallax.com
  • ktekxktekx Posts: 71
    edited 2006-06-02 09:02
    Tom, many cell phones have USB connectors purely for convenience since most computer nowadays have USB, but the pins on the phone itself that the cable connects to usually have TTL serial. Many phones you can still find both a serial or a USB connector for them, you might want to try one of two things:

    1. find a serial cable and connect the pins (remember that some serial cables require a power source to switch the internal circuits, you'll be basically switching from TTL-> RS232 ->TTL)
    2. find the pinouts for that particular cell phone, hack your USB cable up and solder the pins directly to your Stamp


    For my cellular GPS tracker project, I did #2 because it was the easier thing to do since buying a serial cable and interfacing it as RS232 voltage and back to TTL is a bit redundant.

    Hope that helps any, good luck!
  • sam_sam_samsam_sam_sam Posts: 2,286
    edited 2006-06-04 15:00
    stamptrol and ktekx

    I am also interested in what you come up with.

    Please post what you find

    There may be a Project that i thinking about doing some time soon
    When i have the time

    Thanks for your time

    Sam
  • stamptrolstamptrol Posts: 1,731
    edited 2006-06-05 13:23
    ·· Hi all,

    ··· It looks like there are a couple of ways to proceed.

    ··· The original idea of using SMS will be fine if the phone supports access though the cable to the SMS registers in the phone. I now know that all do not, even when the phone itself does SMS quite nicely.

    ·· But, I did find out that many of even the basic phones out there will work very nicely as modems which would be fine for my data logging/alarm reporting. But, many newer phones only offer USB connection cables which are designed to plug into a PC or laptop.

    ·· There is no easy way at present to convert a serial connection into a host-style USB port. However, as one poster pointed out, some phones have both TTL serial and USB at their connectors. Mine, of course, has only USB at the connector. Will chase that avenue down as well.

    ··· I also want to see what I can come up with using the phone's voice activation system. I picture the Stamp using a voice generator to say "Call Fred" then having it tell Fred whats going on at the remote site.

    ··· Post on!

    · Tom Sisk
Sign In or Register to comment.