bluetooth lock. eliminate keys

M

mark.duyvesteyn

Member
Ive had an idea for a while regarding bluetooth locks. the idea is that when in range with ur cellphone, the lock would automatically unlock. Bluetooth has a range of about 10 metres.

Oee way i thought of doing it (cheaply) is pairing a cheap bluetooth ear piece to you phone, and use the different color led (usual red flash for no connection/ green for connection) use a picaxe to read this info some how, and then to trigger a relay/solenoid to unlock the door, or trigger the central locking.

has anyone played round with something like this? cheers
 
M

mark.duyvesteyn

Member
i did do a search for bluetooth

but they arn't really cheap, and probably do a lot more than is needed for this task. i was thinking of more the hack approach lol.
 
C

crossthreaded

New Member
Brilliant idea, at least technically. I think I might be tempted to open the case and connect to the LED legs directly to do the detection; the power supply could be shared too.

I wouldn't like to have to explain to my insurance company if my mobile was stolen though.......
 
M

marcos.placona

Senior Member
I honestly don't think bluetooth is an excellent idea, as you can get it easy cracked. I'd go for an iButton though. I've been playing with this little guys, and they are really cool.

Bluetooth devices ain't no cheap, and hacking a earpiece can be a great exercise. By reading the ADC when it "receives" messages should do, as you'll get the pins high, and know when your device is present or not.

Give it a try and see what you can get. In the worst scenario, you will end up with a broken device ;)
 
P

papaof2

Senior Member
DealExtreme has some bluetooth headsets for under $15US delivered: http://www.dealextreme.com/products.dx/category.508

For those in the US, Computer Geeks has a $4.99US bluetooth headset (plus shipping, but you probably can get a dozen shipped for the same price - might as well, as experimentation can be hard on the devices ;-) http://www.geeks.com/details.asp?invtid=BT3061A&cpc=SCH

I would be inclined to use an RFID device, as the part you carry with you needs no power and can often be added to your keychain. Depending on the intended use, the 8 to 10 cm reading distance of some RFID units is less convenient than the 10m bluetooth distance.

DealExtreme also has an RFID/RFIC card reader/writer and some cards: http://www.dealextreme.com/details.dx/sku.10695 You can find basic readers and pre-configured cards/chips for less.

John
 
hippy

hippy

Ex-Staff (retired)
Never used Bluetooth and no experience of it, but if any phone can automatically get a pairing with the headset then how do you stop anyone with a phone from walking up to the door and it automatically opening for them ?

I'd go with marcos - try it, see what happens. Depending on the headset circuit you may be able to connect its 0V to the PICAXE 0V and simply take a tap off the LED driving line. Worst case would mean using an opto-isolator across that LED.

Most of the complexity is going to be in the PICAXE program, determining when an entry is about to occur and when that window of opportunity has passed. Just because you're in the house and have the phone on you don't necessarily want the door unlocked etc. It's really just a 'householder present' proximity detector so you can develop your software with a switch simulating the Bluetooth receiver having detected its connection.
 
M

marcos.placona

Senior Member
Not without mentioning that bluetooths should be switched off the whole time for security reasons. See why here

I think bluetooth is a very nice technology, but hasn't been handled the right way just yet.
 
You must log in or register to reply here.
Top