Use bluetooth/RF dongle on keychain for car access

**superart** · 06-06-2005, 01:37 AM

Here is my idea:

I want to have a wireless dongle on my keychain that I would keep on my person. When I get within 15' of the car, I want the computer to go on out of hybernate, the LCD to turn on, and the doors to unlock. Then when I get in, I just want to be able to press a button for ignition. Basicly, I want to be able to do what the Lexus GS430 does.

When I'm ready to leave the car, I want to be able to just push the ignition button again to turn the engine off, and leave. When the car senses that the "key" is over 15' away, I want the doors to lock, an the computer to go into hybernate. Of course, I also want the ignition button to become disabled when the "key" is out of range.

How can this be accomplished?

I am thinking the dongle could be either bluetooth or RF. How can we get the computer to come out of hybernate, the doors to unlock, and the ignition button enabled.

I appreciate any input you guys can muster. Thanks.

**0l33l** · 06-06-2005, 01:40 AM

What car do you have now?
Some cars have in chip transponders... without them you won't be able to turn the car on, even if you have the key (without the transponder).

Also, what if you don't want to start the engine, but just listen to music? Wouldn't you be limiting yourself to only total off and everything on?

And I'd like to know too

**Nic** · 06-06-2005, 01:52 AM

if you want your car to respond to bluetooth with the car off you are going to have to build some sort of module that will detect the presence of the device, this is relativley easy to do with a computer but if your computer is off thats not much use to you.

perhaps start by looking here http://www.sparkfun.com/tutorial/Blu...oth_primer.htm

**superart** · 06-06-2005, 02:19 AM

I don't have a car currently (poor broke *** student), although I might be getting my aunts volvo soon...maybe.

What I am going for is a solution that could work on any car.

There are 2 ways to do this that I can currently think of.

One is, have the ignition switch be controlled by the computer. When you push the button, it sends a signal to the computer. The computer checks to see if the "key" is in range. If it is, the computer "hot wires" the car. If it's not, the computer is in hybernate and nothing happens. Or if the car is broken into, the computer found, and turned on manually, then the would be thief pushes the button, the computer would check for the "key", not find it, and not start the engine.

Option two, have the ignition button wired directly to the ignition (just like any normal key), but through a relay. Upon detection of the "key" the computer sends a voltage signal to the relay, allowing the button to connect to the ignition switch.

I'm not sure how to go about doing something like this with a transponder type key. Maybe remotely hide the actual key switch somewhere in the "Engine On" position, then wire it in series with the button, and mount that where the key-switch was.

If I didn't want to turn on the engine, I just wouldn't push the button. The computer comes on automaticly as soon as I get within 15' of the car. I would have the computer as the source of music, or anything else one would want to do in a car with the engine off (except sex, that comes from a different source

). If I drive somewhere, then park, and want to wait with the engine off and music on, I just press the ignition button again to turn off the engine, and the computer stays on.

To turn the computer off, I just leave, and as soon as I get further than arround 15', the computer locks the doors, turns off any lights, and gos into hybernate.

To allow for the computer to turn on, could something like a wake-on-lan type thing be rigged to work off of Bluetooth or RF?

**0l33l** · 06-06-2005, 02:26 AM

This makes sense.

But the only problem is: YOU CAN'T HAVE THE COMPUTER ON 24/7. You'd need to make your own PIC with that bluetooth thing. Plus then you'd have to make a transponder that you carry....

But its definately a worthwile project!

Originally Posted by superart

I don't have a car currently (poor broke *** student), although I might be getting my aunts volvo soon...maybe.

What I am going for is a solution that could work on any car.

There are 2 ways to do this that I can currently think of.

One is, have the ignition switch be controlled by the computer. When you push the button, it sends a signal to the computer. The computer checks to see if the "key" is in range. If it is, the computer "hot wires" the car. If it's not, the computer is in hybernate and nothing happens. Or if the car is broken into, the computer found, and turned on manually, then the would be thief pushes the button, the computer would check for the "key", not find it, and not start the engine.

Option two, have the ignition button wired directly to the ignition (just like any normal key), but through a relay. Upon detection of the "key" the computer sends a voltage signal to the relay, allowing the button to connect to the ignition switch.

I'm not sure how to go about doing something like this with a transponder type key. Maybe remotely hide the actual key switch somewhere in the "Engine On" position, then wire it in series with the button, and mount that where the key-switch was.

If I didn't want to turn on the engine, I just wouldn't push the button. The computer comes on automaticly as soon as I get within 15' of the car. I would have the computer as the source of music, or anything else one would want to do in a car with the engine off (except sex, that comes from a different source

). If I drive somewhere, then park, and want to wait with the engine off and music on, I just press the ignition button again to turn off the engine, and the computer stays on.

To turn the computer off, I just leave, and as soon as I get further than arround 15', the computer locks the doors, turns off any lights, and gos into hybernate.

To allow for the computer to turn on, could something like a wake-on-lan type thing be rigged to work off of Bluetooth or RF?

**superart** · 06-06-2005, 02:32 AM

Fair enough. A small PIC or BASICstamp box that connects to the computer's WOL. The microcontroller could keep an eye out for the bluetooth signal, then send a signal to the WOL to wake the computer up. And I could make a little transponder with a bluetooth chip in it to talk to the PIC box.

I'm not completely sure how to do this, but Nic's link shows a little intro into using bluetooth chips. Im sure a little googleing might help me along with that.

btw, thanks for the link Nic, any more links along those lines?

**0l33l** · 06-06-2005, 02:38 AM

Originally Posted by superart

Fair enough. A small PIC or BASICstamp box that connects to the computer's WOL. The microcontroller could keep an eye out for the bluetooth signal, then send a signal to the WOL to wake the computer up. And I could make a little transponder with a bluetooth chip in it to talk to the PIC box.

I'm not completely sure how to do this, but Nic's link shows a little intro into using bluetooth chips. Im sure a little googleing might help me along with that.

btw, thanks for the link Nic, any more links along those lines?

That sounds like it would work. But I'd do this seperately of the computer. The PIC or BASICstamp should do those functions, not the computer.

**superart** · 06-06-2005, 02:43 AM

yea, but I still want the computer to turn on and off by itself when I get close to/move away from the car.

Turning it on would be relatively easy. Just send a signal from the PIC box to the computers WOL.

How would I get the doors to lock and the computer to turn off when I get away from the car?

I guess I could patch the PIC box into thw power lock system somehow (although not quite sure how).

How would I get the computer to turn off?

**0l33l** · 06-06-2005, 03:02 AM

Originally Posted by superart

yea, but I still want the computer to turn on and off by itself when I get close to/move away from the car.

Turning it on would be relatively easy. Just send a signal from the PIC box to the computers WOL.

How would I get the doors to lock and the computer to turn off when I get away from the car?

I guess I could patch the PIC box into thw power lock system somehow (although not quite sure how).

How would I get the computer to turn off?

Well, have the BT box emulate your ACC line. Hook up a relay that is connected when you're in range. And when you're out of range it should be off. Connect your shut down controlelr to this relay. Problem solved.