In Connecting to Intel® Edison from Android* with Bluetooth* LE (BLE) describes a way to access BT via Arduino code but additional BT shield/kit is required.

It all starts with the HC-05 Bluetooth module, which is meant to transfer serial data, but which can be converted into a general-purpose device costing ten times as much with a simple Flash ROM ...

The HC-05, a Bluetooth to serial bridge, can be found for around $5 on the internet and therefore may be the cheapest way to add Bluetooth connectivity to your project. However, its default setting… ...