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how to make a home security system? Answered


The question is, do you want a smart(er) system or a dumb system? By that I mean do you want one with a microcontroller that needs programming or do you just want something that you can just wire up and use?

Smart(er) systems include a microcontroller that you can hook any variety of sensors (PIR, switches, sound, glass breakage, etc.) to and configure them in software. You would need a good understanding of the programming language of that particular micro in order to accomplish all those things and more, such as contacting external sources (police, relatives, friends, ect.).

Dumb systems are basically self contained hardware units consisting mostly of switches configured to inverting or non-inverting inputs to a central alarm, such as a siren or clanging bell (think firebell). These can be hooked to stand alone dialers to alert the appropriate parties.

There are schematics on the web for both, but if you are  programming challenged, a "dumb' system is probably a safer bet until you can master the microcontroller of your choice.


"Programming Challenged" Yes and I agree. Do you have any microcontrollers to recommend for consideration?

I am an analog man. The closest I get to digital is using the computer. That said, I am an avid reader and from what you say you want to do and where you are, you can start with an Arduino. They are purported to be very easy to program. For more horsepower, use a PIC Propeller. It has 8 individual hubs that process threads individually, so you can do 8 things at once instead of just 1. For the ultimate, you will need to use a real computer, especially if you want reactions to movement on camera, multiple cameras, multiple zones, etc.

What you really need to do before you settle on any one microcontroller or other system is to sit down with a sketch of your property and plan out what you ultimately want to do. Figure out if you really need cameras everywhere or will PIR (Passive InfraRed) detectors work. What entry points need to be monitored and what type do you need there. Keep going until you think you have the coverage you ultimately want. Now count up all the points you marked for security devices and you will see how complicated it can get. That is why they came up with zones. Zones are defined areas where the inputs are basically tied together and fed to one input. That is a gross oversimplification, but it puts the point across. If a fault is triggered in zone "A", you know you have to check in that general area. And so forth and so on.

You should also try to decide if you really need a "input" at a particular location or will one of those "Security Lights" work. They are those PIR controlled lights that come on when you walk near them. It's a matter of trade offs. Do you really need "That" there or will "This" work instead.

So, read up on the input types that have been thrown out to you by everyone here and see how they are to be implemented. Sketch up your system (block diagram style) and then you can start to determine what you actually need to achieve your goal.


Thanks Quercus austrina and thegeeke.
I'll start my home work and keep you posted if you wish.
This is still in thought stage as other projects need completing first.

Thanks Again!

We have one of those, it's a HUGE black tom cat.
He wouldn't stop anyone breaking in but if he sat on them they would never get out of the house ;-)

His name? I called him after one of my favorite things.......


Ooh, he's handsome!

We have a black tuxedo cat that watches us like the panther in the commercial. She is our supervisor cat.


He is handsome and he knows it, he struts regally around the garden with his head & tail held high like O'Mally from The Aristocats.
She looks lovely, i'm not sure our 'ible would even fit into that box let alone have space to move ;-)
We are in th UK so I don't know what commercial you mean, could I find it online?

Holly is fairly small, but can slap a cat twice her size into next week.

Google " geico rescue panther" and a YouTube video will come up. I am on the cranky laptop that won't let me copy and paste the link here. The advertisement features a couple who save money on a home security system by adopting a homeless panther instead. It stares and licks its chops in a menacing way.

Go to YouTube and look up Geico Panther or Geico Rescue Panther. Once you see it, you'll understand my comment below.


What do you want it to do? For the basics, you need some sort of a controller... probably an ardurino or basic stamp (I personally use basic stamp... haven't really gotten into ardurino yet), and some sensors. PIR for motion, magnetic for windows and doors, RFID to deactivate it (or a keypad will also work) and something for it to trigger (such as an alarm).

For any more help than this, you need to provide more details... although I really like CatTrampoline's answer! ;)

Hi all,
First time using this forum so hear I go...
I know the basics of what an alarm system can do. I don't know the terminology ( PIR, basic stamp, ardurino), controller makes sense not sure about zones. So, I would like to build and expand the system as I can.

Things in mind as the system grows;
Combination hardwired and wireless (can't RFID be easily hacked?)
Perimeter notification (property)
Home automation, Smart Home, Active Solar etc.
Battery backup

With that in mind I am east of the Mississippi in a suburb 1/3 acre lot
Lets start with a few windows and doors with on site alarm(horn) then would probably move to e-mail notification next.


Forgot to tell you what you could use for wireless. XBee is used with micro controllers a lot... I've never personally used it, but I understand they're pretty good. Not sure what the range is, or how easy it is to hack them, but maybe ask that question on the forum as well. :)

Basic stamp and arduino are microcontrollers. I wish I started out on arduino rather than basic stamp, so I would suggest that one, but I haven't learned it's language yet, so I couldn't help you with that. (There are people on this site who are experts on it though.) PIR stands for passive infrared, which is basically a motion detector. Zones would be the areas protected by one or more sensors. For wireless, you wouldn't use RFID. RFID stands for radio frequency identification. It's only to verify that you are who you say you are (like those door locks where you put your ID card up to the sensor and it unlocks... That's RFID). RFID is not easily hacked... I have tried to hack my own system a couple of different ways, but failed every time. (Almost got arrested once because I forgot to disconnect it from the phone lines first...) ;) I'm not saying that it's impossible, but your crook would have to be smarter than an old government spook who used to work on the computers... ;)

The only things that I see in your expantion list that I would have a problem implementing are the smart home, active solar, and email. (Possibly home automation... Just because it would be hard to explain online.) I have my system call me (and it used to call the police until I almost got arrested...) when something is tripped. I'm not good enough with programming to interface a micro controller with a computer; although others on this site might be able to help! :)

Good luck, feel free to ask any questions, and welcome to Instructables!

Although you can easily attach micro switches to windows and doors and wire them so an alarm sounds if they are opened. This required people close by to respond. (They rarely do around here)

A more sophisticated system allowing zoning and a better alarm could be made using a microprocessor BUT there is a skill curve to climb to learn to use them.

On the whole it may be better to buy a commercial system. It is reckoned that the visible alarm box on the wall is a significant deterrent.

It would be helpful if you were to elaborate a little.
Do you simply want alarms on doors & windows? do you want cameras? Do you have any electronics experience?
A bit more info about what your needs are may produce far more useful answers.

Buy a gun.