Buzo's cell phone security system project

[Buzo]

This idea is kind of old (from the days where the GPS was not affordable for everybody). But it still applies for my city where there was an average of 50 carjackings per day last year. Not even counting the cars stolen from parking lots!
Not saying that somebody would want to steal my car now, but I want to add a better sound and better wheels, so a good security system is a good start.

I'm thinking in buying a 30 USD cell phone service and add 2 USD every 2 months just to keep it subscribed, so my car can send me a msg if somebody is opening the doors/trunk/hood when the alarm is set. Besides of triggering the horn and lights, of course.

In case of a carjacking, I can call the car and kill the engine from the distance by keeping a key pressed for certain time. This one may not be necessary, I can set the microprocessor to do that for me automatically. But it would be a cool feature to have

So I will need:

1) Subscribe my old cell phone - 30 USD
2) A microprocessor board -Check
3) A bank of rechargeable batteries from an old laptop to be independent of the main battery (in case they make a short in the terminals) -Check
4) Remember to keep adding 2 USD for the phone service before it expires!
5) Have a lot of fun with this new project!

I will not mess with understanding the cell's communication protocol. I will electronically "press" the buttons
a) hang on,
b) navigate through the msg-to-mycel menu and
c) send

Modifications to the cell's keypad will be required and of course, a program in the microprocessor to do the job.

Above's is the basic idea, but I know there are cell phones out there with GPS, so the car could reply me its GPS location everytime I call it.

I'll start with the basic first and leave the GPS thing for later.

[Buzo]

I have 2 cells in my drawer that don't need to be unfold to answer/hang on.

The Nokia in the left had the best reception as I recall, so I picked that one and for my surprise it has the easiest access to the keyboard pad I have ever seen.

The next step would be to program my cell phone in the first place of the list of contacts and then solder some wires for the Menu, Hang on and Call buttons.

[Buzo]

I've been grabbing information from the Manual to get the wiring colors for my install.
The handling of the cellphone should be easy to implement since we are dialing using the keypad. For a mechanics guy, it would be like adding a pneumatic cylinder on the 3 basic keys.
I already have the software and the major part of the hardware ready. Just need to do some bench testing.

I need the following signals and their physical localization in the car:
1) Door lock master switch.- To engage and disengage the alarm with the door's key. - Below the passenger's seat
2) Horn - Fuse box
3) Parking lights - Fuse box
4) Internal light (signal from all door switches) - Back of instrument panel
5) Coil B+, injector B+, fuel pump + or whatever signal to interrupt for the anti-theft.

With above signals its enough for a standard alarm that protects the car from an intruder, but I want to add the anti-carjacking feature which will kill the engine after some time if a hidden switch is not pressed before the timer expires.

The question is what to use as a switch and where to hide it?

Then got the idea of using the memory buttons of the stereo to enter a CODE to disable it, instead of the sw.

However I'm going to stick with the hidden sw for now until I finish the alarm installation and I can receive calls from my car. I'll see whats the next step when I get there.

[Legend_master]

Interesting project, why not use a prepaid phone to prevent you from having to keep paying every month?

[2ndGenGuy]

Man, another badass Buzo project!

I saw a guy once, who instead of using a physical kill switch, he used his cup holders.

Basically, he used a magnetic switch of some sort and mounted it under one of the cup holders. He then put a magnet on the bottom of a cup. So that way if the cup is not in the front cup holder, you can't start the car. He would move it to the other cup holder, and the kill switch would be activated.

It's such a stealth idea, I really love it. But I don't like the idea of your cup falling out and your car dying. But maybe you could implement something equally stealthy. A switch is just too obvious, people will look for that. Your stereo code idea is pretty cool though. Nobody would ever think to try that!

[Nicktorius]

What... the... fuck...?

I'm seriously intrigued and can't wait to see the results.

[obdriver6]

That is a sweet security project!

[ghettogeddy]

if you pull this off i want one...

[Buzo]

Just a quick update.

The bench test was successfully done, and only 6 wires are needed between the micro and the phone as you can see.

I put a 9 pins connector in the PCB to get the signals from the car. The yellow relay in the PCB is the one that will kill the engine if the secret button is not pressed on time.

The first part of the project, which is turning on and off the alarm with the driver's key locking mechanism (+ a hidden push button in case someone has a master key) should be ready by this weekend. Right now the car can already call me in my mobile, but some security features need to be added in order to prevent false triggers.

[Buzo]

if you pull this off i want one...

Sure! I would like to have a version where you don't need to hack the phone to get the keypad's connections, but do everything through the communications port. So no soldering needed.

Let's see how this one works first.

[Buzo]

Man, another badass Buzo project!

I saw a guy once, who instead of using a physical kill switch, he used his cup holders.

Basically, he used a magnetic switch of some sort and mounted it under one of the cup holders. He then put a magnet on the bottom of a cup. So that way if the cup is not in the front cup holder, you can't start the car. He would move it to the other cup holder, and the kill switch would be activated.

It's such a stealth idea, I really love it. But I don't like the idea of your cup falling out and your car dying. But maybe you could implement something equally stealthy. A switch is just too obvious, people will look for that. Your stereo code idea is pretty cool though. Nobody would ever think to try that!

Thanks John!

What we can do is to put a magnetic switch and implement a latch feature, so once the magnet is seen one time, it don't matter if it falls down. Until the next startup, of course.

[Buzo]

Interesting project, why not use a prepaid phone to prevent you from having to keep paying every month?

The cellular system here in Mexico is that your prepaid card will expire if you don't put money frequently, So if you have 50 dlls, it will expire with the time and you need to put at least 1 dll so they re-activate those 50, so now you have 51. At least its not every month, its a 3 or 4 months I guess.
I need to find a good plan, I don't expect to receive a lot of calls excepting for those for testing purposes haha.

[Buzo]

That is a sweet security project!

Thanks! The idea has been around in internet for sometime, but now I have the time and the resources to do it, and a car that is very important for me!

[Buzo]

What... the... fuck...?

I'm seriously intrigued and can't wait to see the results.

Haha the idea sounds kind of weird, but its as simple as one PCB, and a very old cell phone. The circuit and everything will work with the little 3.7 V battery of the cell and will get constantly charged with the car's battery.

Any one that can get "anything" that gives 3 pulses in sequence, can implement this system. It could be time-delay relays, or something similar. I added the microprocessor just because I have a lot of them around the house

[Tomisimo]

If you some of you here tired of me ranting about this and that, here is what I mean. Respect for the guy who do something practical and completely independent, making his car that much harder to steal, but still he shares with you and not keeping it for hem self.

I like your project, would like to see it done. its not my field, but I'm impressed anyway.
and, can you make a video of that noise you having.

[Buzo]

This is the video of the final job

http://www.youtube.com/watch?v=QLkSq...ature=youtu.be

The cellphone interface was really simple to implement, but getting all the needed signals from the car was the time consuming part because I had to start from scratch.

In the video I disabled the horns just because I am a good neighbor but the car flashes the side lights and the horns when the door gets open.

Installed the cellphone and the controller in a small project box so I can safely put it in anyplace inside the car.

The system gets enabled with the door's key switch, the same signal that locks the 4 doors and get's disabled by "doing something" inside the car. When the driver's door is unlocked using the key, a timer starts to run and will trigger the alarm if the secret disabling thing is not done. I'm still fine tuning this value, but it can be around 15 seconds.

For someone that already has a security system installed, doing something like this is really simple, since the only signal needed to get the cell triggered is the one from the horn.

If you pay attention to the audio, there are some beeps that can be heard when setting the alarm and when opening the door, I will eliminate those later, I put them there for debugging purposes only.

[obdriver6]

Oh man that is sick, I need one of those for my car!

[2ndGenGuy]

That's freakin' sweet! DO WANT.

[Buzo]

If you guys want one, I'll be more than happy to supply the microprocessor board already programmed for you. You just need to tell me if you already have a system installed in your car which would simplify everything.

I will program the micro to:

1) set the alarm when 1 pulse from the electronic horn is detected
2) disable it when 2 pulses are detected
3) trigger the call when a continuous signal is detected
4) Ignore the pulses when switching to and from valet mode

If your system does something different than above, just let me know and I will adapt the code for your specific system.

If you have no security system installed then I can ship the micro programmed like mine, but in order to keep it simple I would prefer to supply only the interface with the cellphone, and leave the fuel cut off and the handling of the horn to a professional alarm system. (I'd certainly sleep better)

So If you need a simple calling system I will program the micro to:

1) set the alarm with the drivers door key.
2) unlock the alarm with the drivers door key,
3) but if the button is not pressed in xx secs trigger the call.
4) if any passenger door is open when the car is locked, trigger the call immediately.
5) Use the little buzzer just to hear the status of the systems when you turn the door's key or press the button. One beep-set, two beeps-clear
6) Switch to and from Valet mode by holding the button pressed, you will hear the buzzer telling you when you can release the button.

I visualize that you need to solder 6 wires to the cellphone, two for the battery, two for the green button (call) and two more for the red button (hang up)

You also need Battery, Ground, Ignition and the lock/unlock wire. The push button can be shipped already soldered to the PCB with a long pigtail.

Don't know about other gens if they have the door switch for the electric locks, if not, we can do everything by time delays:

1) Set the alarm some time after the last door was closed
2) If a door gets open, wait xx secs and trigger the alarm if the switch is not pressed.

In order to avoid enabling/disabling the alarm every time, we can tell the car when you want the alarm to be set before you leave it. So you can go in and out everyday and set the alarm only when you go to some unsafe place for instance. Then the day you forgot to set it, is when your stereo system gets stolen haha. So this may be programmable through the push button sw.

Wow, this is the longest reply I have ever made, and if I'm correct, this should be my post #400 in this forum!

[87roach]

That is so very cool haha, great project man.

[Dr_Snooz]

Another excellent project as always!

[Buzo]

Thank you guys for allowing me to put electronics stuff in a primarily mechanics forum.

I've been debugging the software to make sure it works under all conditions. Since I am using the existing signals of the car...
What happen if I turn the car on with the door open?
What happen if I lock the doors before pressing the hidden button? Or after?
What happen if I unlock the car and then close the doors and I don't lock it again? or if I do lock it again?

fun stuff!

[2ndGenGuy]

So many conditions. You always think that something is going to be easy, then you realize you have more combinations of variables than you originally anticipated!

[Buzo]

So many conditions. You always think that something is going to be easy, then you realize you have more combinations of variables than you originally anticipated!

Yes you are right. It always happen to me.

[Buzo]

From all the options I tested I selected the following procedure:

1) Before you leave the car, the hidden button needs to be pressed to let the car know you want to activate the security system

2) But nothing happens, you can open and close doors, turn your car on and off, drive it, or whatever.

3) After you pressed the button, it will wait until you close your car using the driver's door key to set the alarm on.

4) if any passenger door gets open while the locks are down, the alarm will sound and call me immediately.

5) if the drivers door is open (lifting the driver's door lock by hand or with the key) the alarm will wait 30 seconds and check for the hidden button to be pressed.

6) if pressed, the alarm will get cancelled and will go to step 1, if not pressed within 30 seconds, the alarm will sound and call me.

Everything has been permanently installed in the car and tested for a couple of days with no issues.

I'm more than happy with the results of this project!!

Forgot to say that the only way to shut the alarm up once it got activated by an intruder is by pressing the hidden button.
The system will recall the last status even if the battery is disconnected.