Bluetooth 4.0 Scanning
Use hcitool dev to check your Bluetooth adaptors
From the command line use this to scan for Bluetooth devices:sudo hcitool -i hci0 lescan
To connect to the device: sudo gatttool -i hci0 -t random -b <> -I
You will see a prompt which includes the MAC address. Type connect so that you can read/write to the device.
For more information click here: http://joost.damad.be/2013/08/experiments-with-bluetooth-low-energy.html