Bluetooth proximity sensor

[tomm277]

I would like to create a proximity device with a receiver and a small dongle type device which can then be attached to your key ring, which can be attached to the central locking system in your car so if you leave it unlocked once you get over 5 metres away the car will automatically lock itself. However, I don't know which parts/sensors or receiver I will need to use and was hoping someone could point me in the right direction?

[Dwalt]

@tomm277

Here is an example project along those lines.