Need some input for my Senior Project. Talking Knight Rider Alarm
 

Alright guys i got an idea i want to brainstorm on. I have to design something for class dealing with electronics and if necessary some programming. Of course i would rather make this a fun assignment so i was thinking about designing something for my car. I don't think there is something like this already posted but here it is:

A set of sensors located around the car that will notice when an object is approaching. They will need to be active while the car is off and inactive while the car is on. When something comes about a foot away from the car it will trigger a recording hooked up to a PA. The recording doesn't matter but i was thinking about a Robo Cop voice saying "Step away from the Vehicle". I also already have knight rider lights and it would be a plus to add them to the picture.

I got this idea from parents letting there little kids touch my car while i'm at work. I usually can see them through the window and just set off my alarm, but sometimes I don't and they get finger prints all over.

I'm not asking you guys to design this BTW... Pretty much the only part i am having trouble with are the sensors. If you guys can think of any other way to recognize if someone is standing next to the car that would be great. I was thinking about using sound to trigger it but it just seems more reliable to use movement.

I almost got all the wiring of everything else set up including the temporary power to the knight rider lights during a trigger of the sensors. I am however also having problems giving it power ONLY while the car is off... (I don't want it yelling at people driving next to me haha)

Just a brainstorm. Figured you guys were the best ppl to ask.

Thanks

Proximity sensors are what you are looking for. They should be pretty common, since they come on some models of alarm systems and other things that detect aproaching objects. It would definitely be a cool mod! :w00t:

looks like you got the proximity sensors handled

as for the powering... you can use a relay and use the cars IGN/ACC to energize a relay that will open a normally closed switch when it energizes. This means that you'll have 12V powering whatever you need when the car is off but, when it's running then the 12V source will be interrupted.

The only other concern I'd have is how much current draw will this stuff have. A small drain on your battery is acceptable but, you don't want to drain it to the point where you won't be able to start your car. Figuring that out will help with your report too. Profs love a well thought out project.

I think your overlooking the obvious, any alarm system including the factory is only armed when the car is locked and off, just need to get your power there. Hope this helps and good luck with the project.

Damn fine point.

Would just have to find the alarm triggering wire.

yeah that radar sensor looks like it would do the trick.

If you had to build a smaller working prototype though (like for bench testing) I would try using some parking sensors for a proximity switch. You could run power to the sensors, which I assume take very little draw, and have them run to a op-amp/some type of simple logic controller to "turn on" the rest of the circuit when needed. That way the whole thing isn't draining the battery the whole time. Then when the sensor is tripped, bang power is switched on to your PA message and knight rider lights. Program it to cycle at least once, and then continue to cycle the message as long as the prox switch is closed (i.e. someone standing there.)

could be a very cool project!

In 4th year I designed and programmed a little vehicle to autonomously follow a tape line on the floor using LED's and phototransistors and a little PLC. Probably one of the most fun projects I've ever done. At school anyway haha after it passed the "race-track" test of 2 laps around the lab following the squiggly tape line, I programmed it to do donuts and burnouts haha. the prof uses the video of that in his lectures now haha.

Wow, Thanks for all the quick responses! Vuduman67 GOOD CALL!!! haha. Nomad, that link is awesome, thanks!

Proximity sensor would be the best bet... But, i really like wylde1's idea of using the parking sensor... I know you meant for the prototype but if i implement that into the design than i could have it calculate the distance the person is standing from the vehicle. Therefore, tell it to say "You are approaching a secured vehicle" while someone is walking towards the car, "Please step away from the vehice" when someone is X distance from the vehicle, and "Thank you" when they walk away... Of course this would get annoying to actually have on a car, but it would be a cool thing to show off and definitely get me an "A". haha

BTW Wylde1 that sounds like an awesome project... must of been a lot of fun!

I'm going to start the final design in the next few days and then off to the prototype. If anyone is interested in this let me know. Ill try to keep this thread up to date as well.

U R welcome. :headbang:

What you are planning with the parking sensor would work on the bench but would be difficult to do on the car. Ultrasonic sensors are great but they wouldn't work through the windows unlike the radar sensor and they have limited coverage area. You would have to mount at least 1 per side but probably more. This would mean cutting holes in the fenders/doors/quarters/front bumper cover then wiring all of them up together. It would also be a larger drain on you battery (I think, I'm not sure what the draw for each sensor is) than the radar sensor.

So, for your class, go with the parking sensor. IRL, I wouldn't recommend it.

Duly Noted