Home Security - Door Locking Indicator

[NCoops]

My Project:
I am working on a new project; it is a product that attaches to the user's house keys and indicates whether the user has locked their door as they leave the house, or alerts the user if they haven't before they stray too far away from the door.

What are people's thoughts? What would be required as a user? Any feedback is welcomed and would be much appreciated

Thanks
NCoops

[toscal]

A simple red or green light would be enough. I have seen some car alarm systems that have a pager like device which tells you if someone has tried to open a door or the boot etc.
Mind you sending a text message to your phone, via bluetooth would probably be an option. Sending via bluetooth would be instant, as sms texts often aren't.

[Vangelis]

A Bluetooth tag of somekind could be used. This would be small enough to fit on your key ring and provide functionality you describe. Door locked indication could be via red/green led as Toscal mentioned, and the device could alert you to an unlocked door when red led is lit (door unlocked) and the device goes out of bluetooth range (end of drive)

Problem you will have is battery life of the bluetooth tag.. (could be circumvented by some kind of key's holder which incorporated a charge station - inductive maybe?)