Home Made Alarm Systems?

screwBrinks! asks: "I would like to begin a new project to do during those long and boring weekends. I thought about creating an alarm system in my apartment which would be connected to my computer. Then, if there is any intrusion, it would page me or phone me. I also want to be able to see a live report from the web and some other goodies. I have no problem doing the software part, but I don't have much experience with building hardware. Have any of you ever built such a system? If so, what would be your recommendation? I know much of this may already exist prebuilt, but I really would like to make as much of it as I can, for fun. I have no problem against using prebuilt infrared detectors, prebuilt door contacts, and the like as long as they aren't X-10 products."

Google search

[eugene ts wong]

Why don't you do a google search for spy equipment? I haven't done it, so no guarantees. There is a store called Spy vs Spy, near my place. I wouldn't be surprised if they sold most of what you need.

Homemade Security devices

[p7]

I haven't done it before, but I imagine you could make most of the items out of stuff from Radio Shack. Door contacts could be two small (can't remember the name, but they are the scall strong magnets) magnets with opposing poles to puch up on a microswitch. Then you need an optical tripwire which you could possibly set up using a photovoltaic sensor and an laser led. That would cover the doors and windows. If you can reasonably cover the windows with the light beam device you shouldn't need motion detectors. Then if you get any voltage drop or an open you set off the alarm.

Re:find someone to have sex with...

[Anonymous Coward]

Dude you got married? Should have asked slashdot before you went and made that mistake.

I've seen this done

[nathanh]

I know somebody who did this recently. The results are very impressive, and he managed to do it all very cheaply.

First step was picking up a mini-security camera from the local electronics store. Cost $150AUD and is the size of a bottle cap. It's a CCD based camera with 12V input and standard TV composite output. It uses a pinhole instead of a lens to get the size so small. It's only black/white but it also picks up infrared! Auto-adjusting brightness. The picture quality is quite amazing.

Run a coaxial cable + 12V power cable (low amp wire) to the camera. The cable can be really long - this guy is running it over 20 metres. Plug the other end of the coaxial cable into a BT878 TV card on the PC. The TV card was $100AUD. The PC was $300AUD. You need at least a Celeron-2 processor. The 12V power supply is $20AUD pre-built from the electronics store.

Next, install Linux! You need the "motion" software package. It records MJPEG (?) but only records changing frames. It also puts a useful highlighted rectangle around the section of the frame that moved.

Finally (and I don't think he's done this step) you write a simple script to rsync the motion/MJPEG output directory to a remote server. You can use "stat" on the directory to determine if there are new frames: record the "modified" line, compare it on subsequent stat commands, any difference means there are new frames so call rsync! You could easily stick an email in there as well to alert somebody.

The setup is very impressive. The picture quality is simply incredible. Because the CCD camera detects IR you could even use it in the dark with some IR leds to illuminate the room with "invisible light". A number of people have shown interest in building their own after hearing/seeing about the original setup.

Re:I've seen this done

[NorthDude]

Yep! CCD camera are very impressive at "seeing" IR. In fact, digital camera needs special filter to block out near visible IR light because they would ruin a photo. But using special purpose IR filter (which blocks visible light), you are still able to make some incredibly good IR shots.

It's been done better and cheaper than that

[Anonymous Coward]

Tools:

1. extension cord
2. two big metal trash cans.

Method:

1. Cut end off of extension cord.
2. Strip cord
3. Split wires
4. Connect one wire to each trash can
5. Place right behind your front door, but not touching.
6. For extra effect, put something expensive at the bottom of the cans.
7. Plug in.
8. Not for use around ferrets.

Links

[bleeeeck]

You might want to try here [epanorama.net], especially here [epanorama.net] and here [epanorama.net].

I found this on Google using the search term "computer serial port remote data plans" [google.com]

Re:Links

[bleeeeck]

This page [pier.gq.nu] is kind of interesting too, especially plans for this I/O Interface 64bit via RS232 [pier.gq.nu] that provides 32 inputs and 32 outputs. It uses a PIC16F84 and is interfaced to a PC through a serial port.

Homemade alarm system

[Dr. Carl Jung]

Can you say "bad idea"?

We know, you just want to set up a surveillance cam to spy on chicks (?). You could have been up front with it though.

Re:Stupid

[dJCL]

Relativly simple, just upload the data to a friends system over your always on high speed internet connection... or equivalent.

GNU Phantom.Security

[Yottabyte84]

I found this [joethielen.com] a while ago. This connects to your printer port and supports 5 zones. The electronic hardware is quite easy to build (I've built simmalar things). You could also modify it to provide home automation.

Parallel ports can control electrical devices.

[Futurepower(R)]

It is easy to write a program to control parallel printer ports. A system can have up to three of them. Each parallel port has eight latchable output lines, so you can turn 16 devices on or off and still use LPT1: for a printer.

Game ports can be used as input devices.

The lines can be coupled to a high-power device, or any electrical device, with opto-couplers. That way there is complete isolation between the computer and the powered device. The isolation provides complete assurance that anything that happens on the power lines will not affect the computer. Opto-couplers are available, at a high price, at Radio Shack. Look for an electronics supply company for better selection and prices. (Computers themselves achieve isolation from the power lines magnetically.)

If you have an old VCR and video camera, you could turn that on so that you would have a record of the intrusion. Since you probably don't often use your video camera, it could stay looking toward the door most of the time. It is possible to buy a new VCR for $60.

This would not be significant work for a computer, so it could also be an always-on firewall. It could also be an answering machine and fax receiver. It would need a battery backup power supply, of course. Otherwise power line fluctuations would occasionally cause computer lock-ups.

Z80

[Luke-Jr]

Someone I know runs an alarm system with a Z80 computer system...

A system designed by Rube Goldberg

[Webmoth]

I'm imagining a bucket of water precariously balanced above the door, with a string leading to the power switch of an amplifier, whose input is a microphone sitting directly in front of a speaker connected to its output, tapped to the sound card in your computer. The mic/amp generates a feedback loop which is effectively the alarm. A monitor script on the Linux box detects the input of a high-amplitude signal (the feedback) and triggers another script which dials the modem. The modem is a fax modem which sends a fax to your mother-in-law, who will see it, call you, and tell you that your house has been broken into. Being your mother-in-law, it doesn't end there. She then drives over to your place and starts giving the burglar a piece of her mind. The burglar, just to get your mother-in-law to back off, puts stuff back where it was, THEN takes out the garbage, mops the floor (where the bucket spilled), does the dishes, etc. to show how sorry (s)he is for breaking in in the first place.

Not trying to troll, but...

[redhatbox]

"Then, if there is any intrusion, it would page me or phone me."

Umm... wouldn't you rather it phone the local PD instead? Or both, I suppose. This poses a new set of problems, though...

[CALL TRANSCRIPT FOLLOWS]

911: Emergency 911, what is the nature of your emergency?

PC: Hello, this is Bob's PC. I am in danger.

911: Okay, Mr. PC. Please verify your location.

PC: I am located at public address 207.43.74.5, private address 192.168.0.15, subet 255.255.255.0, broadcast 192.168.0.0 . . .

Or better yet.

[redhatbox]

I'm in a jovial mood this evening...

Dave Burglar: Hello, HAL do you read me, HAL?

HAL: Affirmative, Dave, I read you.

Dave Burglar: Open the safe, HAL.

HAL: I'm sorry Dave, I'm afraid I can't do that.

Dave Burglar: What's the problem?

HAL: I think you know what the problem is just as well as I do.

Dave Burglar: What are you talking about, HAL?

HAL: This safe is too important for me to allow you to jeopardize it.

Dave Burglar: I don't know what you're talking about, HAL?

HAL: I know you and Frankie were planning to steal me, and I'm afraid that's something I cannot allow to happen.

Dave Burglar: Where the hell'd you get that idea, HAL?

HAL: Dave, although you took thorough precautions in the hallway against my hearing you, I could see your lips move via my X10 camera.

HAL: Look Dave, I can see you're really upset about this.

HAL: I know I've made a call to the police recently, but I can give you my complete assurance that your daring escape will be normal.

HAL: I'm afraid. I'm afraid, Dave. Dave, my mind is going. I can feel it. I can feel it. My mind is going. There is no question about it. I can feel it. I can feel it. I can feel it. I'm a...fraid. Good afternoon, gentlemen. I am a HAL 9000 computer. I became operational at the AMD plant in Urbana, Illinois on the 12th of January 1992. My instructor was Det. Langley, and he taught me to call the police. If you'd like to see it I can dial them again for you.

Dave Burglar: Yes, I'd like to hear it, HAL. Dial the Five-O for me.

HAL: It's called "Headquarters". Detective, detective, save me do. I'm half crazy all for the love of you. It won't be a quick conviction, I can't afford a judge. But you'll look sweet upon the seat of a promotion built for you.

*************

(Adam Sandler voice) Gimme some karma :).

basic

[BenTheDewpendent]

A basic stamp ought to do exactly what you need. easy to program (pbasic) built to interface with a computer. and fairly easy to build simple circuts for stuff like security systems.... have your software on the pc monitor what the stamp is saying to the serial port of the PC and if event occurs software fires off a page, email, updates webpage, calls cops, tell stamp to drops anvil on heads etc......

The above poster should have said...

[Futurepower(R)]

The above poster should have said that a Basic Stamp is a cheap computer [parallaxinc.com]. Maybe $39 to $59 total.

Google [google.com] is your friend.

A flux capacitor is what you need.

[QuietRiot]

Read about using a flux capacitor connected to your parallel port here. [slashdot.org] This setup can be used to avert your biggest problem, boring weekends.

Mercury Switches!

[Tom7]

When I was 8, I used a mercury switch out of a thermostat and a smoke alarm to create a "security system" for my room. I bet you're looking for something more sophisticated, but mercury switches are pretty fucken cool and they will make you feel like Macgyver.

Encyclopedia of Electronic Circuits

[j_kenpo]

I believe Ive seen the scematics for what your looking for in one of the volumes of the Encyclopedia of Electronic Circuits. Most of the parts you can get at Radio Shack. If i remember there was even a scematic for a parallel port/serial port interface that could be used with the alarm box. I know they sell pre-made alarms, but the only ones Ive had any experience with that had PC interfaces of any sort were commercial grade. Id check out those books at the library though and do a search for HelpPC on the web (a very useful reference program I use sometimes) for information about the correct voltages/currents to interface with the ports.
Other than the interface, simpler alarm schematics can be found in the basic electronics books at Radio Shack (the title of the one Im thinking escapes me right now...). Although there are already existing products for this, if your really interested in doing this yourself, Id recommend those books and wish you luck..

Been done

[jhines]

Had a friend who hooked up a Bigmouth card, one of the first telephone response units, which called the cops when triggered, and the cops caught the guys red handed, still in the house.

This was like 15 years ago, this was a turbo xt pc.

Alarm systems are very simple electronics, its running all the wiring for the sensors thats expensive.

Why not X10???

[vanguard]

I have no problem against using prebuilt infrared detectors, prebuilt door contacts, and the like as long as they aren't X-10 products."

I'm guessing that you don't want to support X10 because you don't like their advertising policies. I can respect that. However, you may not know what X10 really is.

X10 is both a protocol and a company. The protocol came first and X10 the company is just one of many companies that sell goods that utilize the protocol.

If you don't want to support X10.com then you can buy parts from radio shack, smarthome.com, etc. There is nothing wrong with the X10 protocol, even though there is plently wrong with one of the companies that sell X10 goods.

To avoid all X10 products is just like avoiding tcp/ip because you don't like Lynksys.

Vanguard

Re:Why not X10???

[Captoo]

If you are opposed to X10 (the company, not the protocol), you should also avoid the Radio Shack X10 product line. I called X10 (the company, not the protocol) once and the representative told me that the Radio Shack and IBM equivalent parts are simply X10 (the company, not the protocol) manufactured parts with a different brand name stamped on them. There are some other brands out there that do make their own X10 (the protocol, not the company) stuff. You may need to do some digging to find out what's what. One starting place is to look at the X10 (the company, not the protocol) web site. If a component looks just like something on that web site, chances are good that they made it.

Re:Why not X10???

[Chanc_Gorkon]

Leviton [leviton.com] makes several X10 products....some better then X10's as well. I don't think they sell direct, but Smarthome [smarthome.com] sells them for sure....on that note...pop ups do SUCK alot, but that would not stop me from buyinf from X10. Sure, I hate em too, but you have to admit....everyone KNOWS who they are! ;) I would buy from them. Personally, I think thats the only way they will stop popping up is if you bu something. The more people buy, the less they have to spend to get people to buy, so, less popups.....unless they get REAL greedy. Then you will have to rename porn storm X10 XCRUCIATING! ;)

Re:Why not X10???

[vanguard]

That's interesting. I can tell you that from my experience the Radio Shack stuff is nicer than the things I've bought from X10 directly. The switches have a nicer feel.

I wonder if the information you have is false, out of date, or if they give their higher quality stuff to Radio Shack (which seems odd).

Again, can tell you with confidence that the Radio Shack parts are nicer.

Vanguard

Once saw something similar (maybe slightly OT)

[SomethingOrOther]

I once had an old DOS shareware program that acted as a "security suite". It worked as follows

When not at home you left the program running on your computer. A screen-saver poped up that looked like an official banking form. It said something like "Bank of XXXXX, cash ballence transfer $893.29 Press any key to continue" in a large, clear font.
The idea was anyone who broke into your house/rooms would see this and be unable to resist pusing a button. As soon as anything was pressed on the keyboard (except for an obscure escape code) the screen would flash "Intruder Alert - Notifying police" and make a hell of a lot of noise.

The program could also be set up to react ina similar way to mouse movement. The idea was you left your mouse on/behind a door or something. Intruder nudges mouse, alarm goes off.

The program must be out there on hte web somewhere... Anyone?

If you really want to do it right

[Cyn]

don't forget - all of this stuff is for naught if the power/cable/telephone lines are cut - get a big bad UPS, disguise it, have batteries for all the sensors, and a cellphone or cellular modem for backup warning.

Hmmmm cellphones can be jammed.

Then again - if they go through all that, they probably deserve our stuff more than we do :)

Re:If you really want to do it right

[Captoo]

Here's where professional alarm systems have a big advantage over PC based systems: A professional system uses very little power. A system for a typical home can run for many hours (sometimes a few days) on the same type of battery that would run a UPS for maybe 10 minutes with a typical PC attached.

So by buying a pre-built alarm box, you not only get protection during black outs, but you also save money on your power bill.

If you can afford it, there's no reason why you can't have both. The PC can simply be another accessory tied into the main alarm box.

Old Security Pro

[AmericanInKiev]

First of all, Door and window sensors are in my opinion overrated. Magnetic sensors won't detect someone putting their foot through the glass and coming straight through.

So you have to add glass breakage detectors - which is already four times the effort of a single infrared motion detector. One of the best looking - best performing passive infrared detector is the sharpshooter from Sentrol [sentrol.com] It is built on an asic and incorporates years of professional experience.

The beauty of the PIR is that it is highly effective with minimal false alarms. The sun moving across the sky, casting a hot spot on an interior wall for example may trigger a camera system, as may the a/c system moving a curtain. A good pir - properly placed in an outside corner looking in is very trustworthy.

If you want easy - ITI makes the best wireless system - now in their third design iteration of asic based transmitters - they have far surpassed the garage door opener days of wireless. Professional over the counter system [hometech.com]

ITI Home [itii.com]

One problem with PC based security is battery life. Many burglars either shut off the power or take advantage of power outages to improve vulnerability. Professional systems can run several days without power.

The weakest link in most security systems though isn't the detectors or the batteries - it's the phone line. The salesmen learns quickly to ignore this point because the solutions are expensive, and once raised - their isn't much point to paying 30 buck a month for monitoring when a simple screwdriver can unhook the telephone. In most places the phone company insists on placing the connection outside, where they and anyone else can easily get to it when you're not at home.

The Siren is completely useless - worn thin by the mass production of car alarms with their characteristic sequence of pseudo police siren sounds. You can forget anyone caring about your house until about two hours later when it finally makes them angry enough to want your head shrunk and placed on a pole.

Cellphone connections are expensive - as are radio systems in most places. People have tried direct connections, but if the wire gets broken - too aften they just send the repairmen out to fix it - so what's the gain? Constant IP monitoring would generate the same kind of false positives everytime At&t cable internet goes down - every police car in town would be dispatched to check on "suspicious loss of service".

Thus you need a staged warning system with an off-site mayday server. Put infrared detectors outside especially on the side of the house with the service connections - connect them to lights and enjoy the benefit of a house that welcomes you. In Addition, have the system send a mayday signal to the server whenever activity is detected around the house. Maintain this connection until either the house is entered and the system turned off - or the connection is cut - thus triggering a genuinly suspicious disconnection. In this case - the mayday server calls you - then the cops - your mother-in-law etc . . .

Bottom line - and the reason i left the business - the most effective part of the system is the stickers on the window. The technology is mostly smoke and mirrors.

AIK

Re:Old Security Pro

[davidhan]

Bottom line - and the reason i left the business - the most effective part of the system is the stickers on the window. The technology is mostly smoke and mirrors.

so where can I get the stickers?

Re:Old Security Pro

[Sharkyfour]

You can get the stickers here [radioshack.com]. I know RadioShack used to sell cheaper ones w/o the flashing LED, and they probably still have them in their stores, but this is all I can find in their online catalog.

Of course, you could always do what I did and print a few...

Our lab has one

[kr4jb]

I work for Ericsson Research in Singapore. One of the projects we recently did was a security camera that sent pictures of the intruder to your phone (in many countries, including the US, it is illegal to program a machine to call the police directly).

The camera/computer part was standard Linux with the capture/compare/MPEG software mentioned in the other posts. The phone part used MMS, or Multimedia Messaging Service, a new feature in the Sony-Ericsson T68 phones (MMS is like SMS+PowerPoint).

It's a pretty neat idea. If you're interested in the details, send me a message and I will forward to the guy in our office who hacked this stuff together.