The Bluetooth module wants 3.3v logic levels so that is taken into account. The image above shows a buffer chip doing the conversion, but the Fritzing schematic on the post uses a voltage divider.

A FT-232 USB to serial board is used to program the Arduino. A standard Bluetooth module has to have HID firmware installed. [Dastardly] makes a homemade daughterboard–er, ...

Today, Coin announced that it will offer up an Arduino Bluetooth Low Energy module that's designed to be small and easy to integrate into hardware hacks and products of all kinds.

The Arduino, Bluetooth module (check your specs, some HC-05, and HC-06 may come on a breakout board expecting 5V), and USB Host shield all run off of 3.3V, but devices you want to plug into the ...

Bluetooth 4.0's Bluetooth Low Energy (BLE) feature allows the microcontroller to run on power sources as small as a button-cell battery for some applications—and the team has developed a "shield ...

Supporting Bluetooth 4.0 a serial protocol that allows the LBM313 Bluetooth Low Energy module and Atmega328p to communicate both messages from the client which can be PC, Mac, iOS or Android to ...