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DigiTan
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Posted: 04 Oct 2004 09:15:06 pm    Post subject:

I'm thinking about a mod project to guard calculators, and I want to get some feedback....

The basic idea is to have a miniature sensor that can detect when the calc is being picked up or tilted. If you go to school/work and you have to leave your calc out in the open for whatever reason, you can just activate a guard feature and walk away. If anyone moves or tilts the calc, it sets off a small (but annoying) alarm that won't stop until you enter some kind of code. The alarm system would be small enough to hide inside the casing, and it would have a self-contained power supply; so removing the normal batteries wouldn't affect it.

Anyway, I haven't built this or anything, and I don't plan to as of yet. But I've heard alot of horror stories about stolen calcs and thought it would interesting to ask. How does it sound?
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Toksyuryel
Crimson Dragon Software


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Joined: 14 Jun 2003
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Posted: 04 Oct 2004 11:24:10 pm    Post subject:

I've had my calc stolen before (never got it back either :'(), so I know the feeling. I would definitly get something like this if it fit my price range. Possible suggestion: a little infrared "key" that could be used in the same way you work your car alarm.

Last edited by Guest on 04 Oct 2004 11:24:55 pm; edited 1 time in total
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DigiTan
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Posted: 04 Oct 2004 11:30:56 pm    Post subject:

A fine suggestion! Actually I was thinking of doing something like that for my backpack. Sort of like a vehicle alarm. I haven't had my calc or backpack stolen, but I've had some close calls, and I think this idea could take off. Large models like the TI-92 and Voyage would be great candidates in my opinion because of the size (lots of room for a loud buzzer). And an IR option could maybe keep people from "spying" on your password.
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Toksyuryel
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Posted: 04 Oct 2004 11:36:28 pm    Post subject:

Better yet, have the password be transmitted via the IR device, as a series of keypresses you'd need to punch in. That way, if the "key" fell into a thief's hands and they knew what it was for, they still wouldn't have access because they wouldn't know the password.
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DigiTan
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Posted: 04 Oct 2004 11:42:21 pm    Post subject:

Another killer idea! I guess it could have maybe 4 or 5 buttons on it (1 "arm" button, and the rest "code" buttons).
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Brazucs
I have no idea what my avatar is.


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Joined: 31 Mar 2004
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Posted: 05 Oct 2004 01:11:26 am    Post subject:

lol.. like a car! Make it flash and beep twice when you activate it.
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leofox
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Posted: 05 Oct 2004 06:56:35 am    Post subject:

sounds like a nice idea, lots of calc get stolen every day, and buying a new one is expensive. It also helps ágainst 'friends' that 'lend' your calc without asking.
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DigiTan
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Posted: 05 Oct 2004 02:06:48 pm    Post subject:

Well I guess the IR feature is a winner then! Now there's the sensor problem. I was thinking of maybe a having a precision accelerometer (acceleration meter) gaurd the calc--that why you could detect tilting and movement. After I did some research, though I found out they can be "killed" by dropping them. There more rugged designs out there of course, but now I want to try a tilt sensor (no mercury).

The disadvantage is that it wouldn't be able to respond to carefull movement. The calc would have to be tilted at least 30 degrees (choose whatever axis) for the alarm to be triggered. Would the simpler tilt sensor do the job or the accelerometer the better choice?
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Toksyuryel
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Posted: 05 Oct 2004 04:24:50 pm    Post subject:

Well, most people aren't likly to be aware of the security device (it is a calculator after all Smile) and as they are trying to steal the thing they aren't going to be worried about a little tilting, you probably don't have much to worry about with the tilt sensor.

Last edited by Guest on 05 Oct 2004 04:25:10 pm; edited 1 time in total
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Mike_k


Newbie


Joined: 16 Sep 2004
Posts: 45

Posted: 05 Oct 2004 11:55:33 pm    Post subject:

To combat the tilt issue, just have the alarm keep going even if the tilt is cut off (IE: broken by a drop) A problem I see, is how to turn off the alarm if the alarm is stand alone in the calculator? I mean, if it's not connected to the calc itself, (just inside the case) how could you check for keypresses? An IR car ring thing would be a must.
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DigiTan
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Posted: 06 Oct 2004 02:01:49 pm    Post subject:

That's a good point. I figure maybe it could work so that when you arm the calc, the alarm "remembers" whatever tilt it recorded. That way --if you wanted-- you could arm the calc while it's sitting on an incline (or even upside-down), so that the theif couldn't ever hold it upright. :lol:

Turning the alarm off might be a problem if you lost the key ring. Maybe it would have to be linked to some calc software somehow as a 2nd option. Of course, if your MEM resets somehow then you're really screwed!
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DarkerLine
ceci n'est pas une |


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Posted: 06 Oct 2004 04:26:15 pm    Post subject:

Maybe you should make it so that you have to turn on the calc using the IR key instead of the [on] button?
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Toksyuryel
Crimson Dragon Software


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Posted: 06 Oct 2004 06:29:55 pm    Post subject:

oo me likes this idea Smile *nods and agrees with Sir Robin, then looks at DigiTan expectantly*
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DarkerLine
ceci n'est pas une |


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Posted: 06 Oct 2004 06:55:14 pm    Post subject:

then if a thief uses the [on] button..

BOOOM!!

(alright, maybe not that, just an alarm..)
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DigiTan
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Posted: 06 Oct 2004 10:33:35 pm    Post subject:

Quote:
BOOOM!!

LOL! That reminds me of one guy at school who hid fireworks in his pens because he was always getting ripped off. He'd stuff some "booby trap" firecrackers in there, have a string hanging out to make the victim curious, leave, and wait for somebody to take the bait. Anyway, we're sitting there in chemistry once and there's this loud "BANG!" We look back he's holding half a pen with a bunch of smoke around him; trying to look like nothing happened. Laughing

I guess we could do the IR = [on] key thing, as long as there's still room for an alarm. Maybe it won't blow up or leave a bunch of ink on you like the banks, but it will definatly turn some heads!
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Jeremiah Walgren
General Operations Director


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Joined: 24 May 2003
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Posted: 06 Oct 2004 11:35:41 pm    Post subject:

I think it sounds interesting... Though not something I'd implement into my calculator. It's almost three years old, so it getting stolen would be an excuse to buy another one.

I would, however, be very sad about the theft of such a precious item...
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Jeffrey


Member


Joined: 12 Jun 2003
Posts: 212

Posted: 07 Oct 2004 11:39:23 am    Post subject:

Interesting, yes. Practical, no. Best Buy already offers an electronics protection device that sounds an alarm if the receiver travels more than 20 feet from the device. It costs around $20.
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DigiTan
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Posted: 07 Oct 2004 03:01:05 pm    Post subject:

Quote:
Best Buy

What?!!? Those crooks!!! They stole my Calc Guardian idea!

Well, I do have to give them credit for the whole 20-feet thing. When I worked in retail, our Loss Prevention departments used similar devices that could be tied around product packages--so that taking it out of the store or tampering with the strings would set it off, but they weren't shock sensitive. I think the problem with a 20-foot "fuse" is that a theif might be able to shove it into a bag so that no one would hear the alarm. Anyway, I'll try to check out this Best Buy thing...
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jvdthwip


Advanced Newbie


Joined: 21 Jun 2004
Posts: 93

Posted: 23 Oct 2004 04:57:53 pm    Post subject:

"20-Foot Fuse"...
You'd have to arm it and disarm it every time you take it out to use it, becuase it's likely to go off... say... when you drop it off in a locker, use the restroom, go to P.E., actually lend it to a friend, and so on... It would be unpractical, except if you were worried more about a pickpocketer/shoplifter scenario rather than a person swiping it from your desk...

The alarm idea still isn't a bad idea, though... Just not an exceeded vicinity detector... Maybe you could arm it and disarm it with a password.
Quote:
Maybe it would have to be linked to some calc software somehow as a 2nd option. Of course, if your MEM resets somehow then you're really screwed!

Not necessarily, just have the calc send a "arm"- or "disarm"-like command, it doesn't have to store anything, and the program can be a FlashApp... The password would be in an archived variable, one would assume. Even if they reset the calc's ram, and were able to use the calculator, the alarm would still be going off, requiring the "disarm" command from the APP, only accessible with the password stored in the archived variable that is only changeable if you know the password to change it.

What if they delete the variable?
Make a windows program (VB or C), another calc program, or something like that, that asks for a password and outputs an appvar. The appvar would be used by the APP, but the app itself would be unable to create a new variable. (And the alarm would still be going off, even if you deleted the variable from the calc).

What if the enemy created a new variable, ran my calc to a computer with a link as fast as they could or used their own calc, and sent a new appvar with their ownpassword?
If they were that prepared, why steal your calc among anyone else's, say, the person sitting next to you?

Just a few thoughts... Neutral


Last edited by Guest on 23 Oct 2004 05:12:22 pm; edited 1 time in total
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DigiTan
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Joined: 10 Nov 2003
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Posted: 23 Oct 2004 05:36:52 pm    Post subject:

Yeah a password-protected App is a good strategy. The main type of calc theif I'm worried about is the typical student/coworker who probably isn't familair with appvars. I guess the main goal is to avoid those "abondoned calc" scenaros where you might leave your calc under a desk or something, leave, and find it stolen an hour or so later. Basically I think the best thing to do here is prevent the calc from leaving the room; or if someone does take it--at least create a scene so the guy gets caught in the act (or at least really, really suprised). False alarms might be less of a concern, since it's the user's responiciblity to re-enter his password each time.

Anyway, it's not very calc-related-- but I started on a larger version of this, and I'm really liking the IR keychain idea (though it would be expensive at first, but it only cost an extra ~$6). So far it's too big to fit inside a calc because I ran out of small processors, but the overall system could've worked just as well in a calc.


Last edited by Guest on 23 Oct 2004 05:37:22 pm; edited 1 time in total
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