In Cambridge, UK
Bluetooth LE on the Raspberry Pi
The Raspberry Pi Model 3 has built-in support for Bluetooth Low Energy (BLE). BLE is the technology behind many fitness trackers and smartwatches, and allows small, low-power devices to transmit and receive information from a central computer or smartphone.
This tutorial gets you started with Bluetooth Low Energy using a Texas Instruments CC2650 SensorTag - these are small, robust, relatively cheap and do interesting things out of the box. You can buy one directly from TI, or in the UK they are available from RS and Farnell.
BlueZ 5.4 build on Raspberry Pi
Standard Wheezy bluez package is 4.99 and doesn't have LE support.
wget https://www.kernel.org/pub/linux/bluetooth/bluez-5.4.tar.xz xz -d bluez-5.4.tar.xz tar xf bluez-5.4.tar sudo apt-get install libglib2.0-dev sudo apt-get install libdbus-1-dev libdbus-glib-1-dev sudo apt-get install libusb-dev sudo apt-get install libudev-dev sudo apt-get install libical-dev sudo apt-get install libreadline-dev ./configure --disable-systemd make sudo make install
Notes: Tests use: 2014-01-07-wheezy-raspbian.zip from http://downloads.raspberrypi.org/raspbian_latest