I Need Help, Please Someone !

[skimask]

Maybe if each 'friendly' had their own RFID tag or pulsing IR transmitter and/or badge or something along those lines.
Heck, let's start putting UPC labels on everybodys forehead (or fivehead)...

[Melanie]

Sounds like another school project...

You could limit your 'friendly' pets to weighing 20kg or less. Then cover your floor in Pressure mats that trigger over 35kg. Finally it would take two consequive triggers of the mat for an alarm condition (accounts for your 'friendly' pet jumping down from a high level).

Process your IR sensor (or even camera video) output by a DSP to determine the size of your target. Anything over a given size is considered 'not friendly'. Add-in further intelligent processing to descriminate between pet movement and habits and the kind taken by an intruder. It's unlikely your pet will open your fridge, drawers and cupboards... and an intruder is unlikely to spend time at the feeding bowl, grit-tray or curl-up in a warm corner for a couple of hours.

Folks have forgotten about permiter protection. If a house is secure, pets will enter/exit via a cat-flap for example. Intruders will enter via doors, windows and through the roof. Everyone want's to put up volumetric protection nowadays - because it's cheap, easy to deploy and it maximises the sellers/installers profits. Perimeter protection is more costly, but in a domestic environment is a far better option.

Finally, cover your house in standard PIR sensors, limit your pets to cold-blooded species (like Lawyers and Bank Managers).

Please make cheques payable to Melanie...

[manwolf]

How about basing it the height of the subject as well as other sensor? Unless of course people are keeping 800 lb gorillas in the house.

Melanie had better hope her Banker and Lawyer never take up PICs as a hobby!

[gringobomba14]

The problem with bankers and lawyers is that they look and smell too much like real people, so it is very difficult to differentiate between them and us.

RFID tags are one way to go for detecting friends from foe, but if you really want to get into it, you can use biometric stuff. There are some open source programs availale out there, and basically all you do is point your camera at the door or cat flap in question and if the computer recognises the shape of the face (or hind quarter if they are on the way out) then they are one of the family. Drawbacks are that it will have to be PC based, but there is less to actually build. The other advantage is that there are several programs out there that will send an SMS or MMS from your computer to a designated mobile. BUT, it's really all out there and ready made for you, and that is just BOOOOOOORRRRRRIIIIINNNNNGGGGG

[Acetronics2]

Hi,

I have a friend who found the best alarm you can find :

he's found of venomous snakes ...

The day they quietly live in their vivariums, all around the shop, at everyone's sight ... and at night their job is to inspect the bikes exposed ...

Nobody ever stoled him anything ...

Alain