I built this circuit recently and decided to do a rough schematic and post it here.It is a car alarm.You need to mount the sensor and led where they are visible from a window .I made the transmitter out of smt parts and mounted it in a keychain led flashlight.when you turn it on the led comes on and it waits for a signal from the sensors .If it gets a signal from a sensor it turns on a relay which I'm connecting to my horn.You have to have line of sight and be pretty close to control it .

Could anyone suggest some sensors?

I made my own vibration sensor.
I took a piece of a retractable radio antenna and hooked it to one lead.
I hooked the other lead to a nail hung in the center of the antenna tube.
then I hung the whole thing so that if you park on a hill it will lean .
Sort of a wind chime crossed with a bell.
I had to use really fine motor wire with thread to support the weight.
What would be awesome is If the whole vehicle body was made into a proximity sensor.

Here is the ROUGH drawing of the schematics and the .asm files.

And thanks to Nigel for showing me how to do the infrared stuff
There are some connections not showing such as power and a 5v regulator but you get the idea. Don't forget when you build the transmitter the button cells have a positive shell . I assumed it was negative now I'm trying to get them in backwards.

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Attached Files

	irtx12f615 .txt (4.6 KB, 381 views)
	iralarm16f628.txt (8.1 KB, 290 views)

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as for a sensor use a laser pointer and a photocell as the sensor

 

Thanks for your idea.

I saw some laser pointers at the local dollar store for $1.
I even noticed the plastic box would make a good project box.
I see you're new so I'll say welcome to the forum.

That's what I like about the internet, people trading ideas.

Just so this post isn't completely useless I would like to mention that the transmitter by itself would make a good trick remote .You could turn off all those annoying T.V.s at the stores.

That's why I used linux lirc detector to add mute and power to the code list I got from Nigel.
You can use a universal remote and record the signal for different model of T.V. ,then figure out how to recreate it.
This was my first time etching a circuit with peroxide+hydrochloric. It worked great

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Actually, the Internet is about war =)
It started out as a DARPA project for transfering information for intercepting incoming bomber information and was funded by the governement as a fault tollerant network. Everything that came after was a 'well what else can we make it do' sort of thing. Kind of like the modern day Internet, which explains why there's so much crap.

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Interesting observation. A little off topic , but I'll go with it.
Really the internet gives us our own choice ,It's pretty much neutral.
If you have time check out this video .

http://video.google.com/videoplay?do...666768&q=spime

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