Bluetooth LE is good enough for short-range communication, and there are a ton of boards and Kickstarter projects ... above Arduino level – and an HM-10 Bluetooth 4.0 Low Energy module.

The project uses ... it to work on 5V. An Arduino mini pro provides the brains. A FT-232 USB to serial board is used to program the Arduino. A standard Bluetooth module has to have HID firmware ...