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Car Alarm System

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New Member
I'm going to work on a project soon, but I need to make sure that the project I thought to work on is viable:

Now in a car I thought I would embedd circuitry, microcontroller controlled which would be connected to the Panic Circuitry of the car (the security system ), if the panic circuitry is enabled, the embedded circuitry calls out your mobile phone number to alarm you.

Now the embedded circuitry will be interfaced with a cell phone. which calls your number up, when the car panics?

So is this project viable? I think it can be implemented, but with viability I'm talking about cost, usefullness?


Active Member
Sounds like it would get kinda expensive having to pay for a cell phone that would just be kept in the car all the time.

There are already quite a few 2-way communication car alarms on the market. it just uses radio waves to communicate, so you have to be within a certain range for them to work.
I messed around with mine, and I estimated the range to be 1500-2000ft.
I'm sure there are better units out there that can go even further.

If you really think about it, how often are you that far away from your car? and if you are outside of that 2000ft range, chances are the person who is breaking in will have finshed what he was doing (stealing the car itself, or just jackin the stereo) by the tiime you get there anyways.

If you can figure out a way to get a cell phone in there to make calls for free, it might be worth it.


New Member
They have those emergency cell phones that cost very little compared to a normal cell phone, but it only calls emergency numbers (Fire, Police, 911). That would probably work well, but you have to think about false alarms and such. I doubt the police would be very happy to rush to your car only to find a tree fell on it. lol


Active Member
Even if you did do that though, you would have to tell the police where to find your car, and thats just a whole new can of worms...


New Member
www.sparkfun.com has low cost GSM modules. These modules are designed to let you design cell phoe capability into embedded systems. Sparkfin also has cheap GPS module. All you need is a Text to Speech chip and you can have the car tell you it's location over your cell phone. Come to think of it I think there was a Circuit Cellar article about this same thing a while ago.

As long as you are puting a cell capability into the car you could add a bluetooth module to interface with a hands free headset. This would give you a built in car phone.


Active Member

they have those "pay as you go" phones. no monthly charge or anything, you just get charged when you make a call. i think you have to renew them each year or two years or something like that, but thats no big deal.

ive had the same idea :lol: . i was even thinking of somehow making it so that you can call the phone in the car, it will activate some high voltage on the body of the car, so you can watch as the would be thief gets zapped :twisted:
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