Controlling a circuit via SMS

Hi folkes,

I wish to switch on and off a circuit via SMS (text messaging). I'd also be interested in sending messages directing when and for how long the circuit should be switch on for. To do this, am I right in saying that I need a GSM module and a microcontroller? What model of GSM module would you recommend?

Lets say I wished to complicate things further by adding a LCD display, in order to show the status of the circuit (whether on or off, if it is scheduled to come on etc), what kind of contoller would be suitable in this case?

I was also thinking that it might be necessary to include a key pad. This would allow the user to enter the mobile number that the circuit should respond to (stop others interfering with the circuit). Or the keypad could be used for entering a pin number for the device, and this pin would be requested in order for the user to be granted access to switching on and off the system via their phone.

So to sum up, I think I'm right in saying that I need a GSM module, a microcontroller, a keypad (12 keys should be more than enough) and a LCD display (20 x 4 LCD module perhaps?). Can you recommend me models for these 4 devices as I'm not at all familiar with this area and there is so many devices out there.

Any other advice?

Thanks very much for your help,

Barry.

Reply to
bg_ie
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Hey,

Have you considered using a normal GSM phone that can be controlled over a data cable?

The article at

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discusses something like that using an Ericson phone, but I would expect a similar method to work for other brands also.

greetings, Tom

Reply to
Tom

Google for SMS controllers, and you will find a few projects.

As long as you are not in North America.

I have yet to find a carrier that will allow you to get serial data from a regular cell phone.

But you can buy special radio modems that offer SMS service.

donald

Reply to
Donald

I read in sci.electronics.design that bg snipped-for-privacy@yahoo.com wrote (in ) about 'Controlling a circuit via SMS', on Tue, 27 Sep 2005:

We don't tell people how to switch things on with mobile phones, in case they go BANG!

--
Regards, John Woodgate, OOO - Own Opinions Only.
If everything has been designed, a god designed evolution by natural selection.
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Reply to
John Woodgate

You're a bomb maker ?

Graham

Reply to
Pooh Bear

I'm actually a student looking for some ideas for my final year project. I was thinking of a remote controller that would allow people to turn on and off their home heating system. This would facilitate people in turning off their heating if they were delayed at work for example, and set it for a later time. I didn't anticipate for a second that there would have been such a paranoid response to my question. You do all realise that if someone wants to kill someone it doesn't require any degree of imagination or sophistication. Where there's a will, there's a way. I don't see why terrorists should be given a monopoly over technology, while people like myself are made to feel stupid for asking simple, straightforward questions. Some of you people are playing right into the hands of terrorist by helping them in their mission to spread fear and paranoia to our society.

Anyway, thanks for those who did reply in a constructive fashion. I've come across this very useful article -

SMS Controller, Part 1:

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SMS Controller, Part 2:
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SMS Controller, Addons:
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The microcontroller referred to in this article is the AT90S8515. Would it be capable of controlling a small keypad and a small lcd display also do you think?

Thanks,

Barry.

Reply to
bg_ie

I read in sci.electronics.design that bg snipped-for-privacy@yahoo.com wrote (in ) about 'Controlling a circuit via SMS', on Wed, 28 Sep 2005:

It's not paranoid. Don't be rude to your elders.

Not all potential bombers are highly-educated or inventive. Some would indeed be stupid enough to ask on a newsgroup how to construct a bomb. There is, after all, quite a lot of relevant information elsewhere on the Internet.

If you'd explained about being a student, and wanting to do a project, by the way, that's been done by thousands of students over the past 20 years or so, so is a mite unoriginal, you might have received fewer suspicious replies.

--
Regards, John Woodgate, OOO - Own Opinions Only.
If everything has been designed, a god designed evolution by natural selection.
 Click to see the full signature
Reply to
John Woodgate

If Barry is being rude, then John you are being both pompous and boorish to the extreme. Clearly the question was left open because the student hasn't yet settled on the exact application he wishes to proceed with. And as for paranoia, do we now have to state our profession in order to receive a satisfactory answer to our questions? You do realize that the London bombers were students at a Leeds university? Not that they actually used SMS. I'm also sure a bomber could manage to go online and pretend he was a student, no?

Barry, that microcontroller should work fine for what you wish to achieve. Have you chosen a supervisor yet? If not, find a lecturer with experience in the control field and talk to them about your idea. Your supervisor might well have an area of expertise which SMS control could be applied to. You might also have a look at Maxim's microlan devices. These include temperature sensors/loggers and ADCs etc, which can be organized on a simple 1-wire network.

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John Woodgate wrote:

Reply to
cathal_campbell_shaw

Silicon Chip did a project on this:

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Dave :)

Reply to
David L. Jones

SMS controllers using GSM and CDMA phones have been readily available for some time. Try

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for a start.

Pete

Reply to
Peter K

These ;-)

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The bumf sez: """ The GT47/GT48 can be configured to independently perform control and alarming functions using a built-in scripting engine, minimizing the need for extra components. This means the GT47/GT48 can be programmed to communicate with the connected asset intuitively, therefore enabling users to add metering, and other local control functions as required. The outcome is a more customized, efficient, and costeffective M2M application.

""" What you want, not?

Siemens does/did a Linux-based development board too - around USD200, colleague bought it for fun - but their crap website defies any attempt at locating actual products!! So that's some homework for you.

Use the one that's inside the Kit.

The small Epson/Seiko LCD's are easy to drive once one (eventually) gets the critical timing requirements and the undocumented character memory layout right. Or use an embedded PC as an ASCII terminal and gloss it up with one of the interfaces/GUI's that comes with Linux.

I think your life would be easier if you use "encrypted command strings over SMS" purely as the signalling protocol and then use one of the advanced mobile handsets to handle the actual communication with the user - the Java-enabled handsets in general have good free-of-charge development systems for them. The sucessful decryption of a command is the validation. The crypto can be made as strong as you care to wait for it. The problem with PIN codes is that either you have to enter it with each command or you have to have some protocol to deal with the asyncronous nature of texting - i.e. Which command are you validating Now? If you think that is not a problem, then look at the perpetual brokeness of SNMP implementations and reconsider.

You should certainly check if there actually is access to the SMS engine in software, in *many* cases all you get is HTTP 1.1 with J2ME and you need a Binary/Native application instead (the Mobile Games development kits is where one finds the gratis development systems for native applications).

When asking question on News, Specify what you want TO ACHIEVE in DETAIL - Do you merely want to BUILD a GSM M2M controller or do you want to USE the functionality for .... WHAT, exactly. Someone might have done it already, and know some extra things to look out for.

You - and everybody else - will get better answers that way!!

Reply to
Frithiof Andreas Jensen

Thinking a bit more:

*If* you get a GPRS M2M module, wich will have always-on TCP/IP anyway and a half-decent CPU to boot, why not have it serve up a WEB page with the controls of whatever you want to do, including access control and validation? Or stick an embedded Linux box at the end of it for about as much power as you want to pay for.

That will work with *anything* on the planet and reduce the programming task to the Server side. The client does HTTP anyway. Does away with the need for a special SMS interface too.

... And Users WANT pretty pictures!!

Reply to
Frithiof Andreas Jensen

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