If you do projects with Arduino So buy this plate is a great option, because it allows you to add communication Bluetooth on any project.
The card is small and functional. Is fed with the VCC (5V) and mass of the Arduino and just needs two additional pins: TX and RX.
The antenna is this “cobrinha” made with printed even.
The connection to the Arduino is easy: RX pin 0 (ZERO) and TX pin 1 (A). Aside from VCC to 5V and GND to GND of the Arduino. Attention only to a detail, this connection switches the USB serial connection, then send the program before connecting the pins and a.
To do the Arduino receive data via bluetooth is simple, just pair with any Android device, or Windows and open a serial terminal. Anything that you send via this terminal the serial Arduino receives like a conventional USB port. There's no complication! Simply pair the device HC-06 the photo below:
To test I compiled a simple program, that's on this page of examples of programs for Arduino, and an led that lights up when it receives a letter H on serial port. The code of the letter is sent by the Bluetooth terminal, received by the Board and submitted to the Arduino for wired serial.
Perfect! Although I still think that it could be a little cheaper. But works perfectly, being even possible to use along with the serial USB Wired, but for that you will need to use the bluetooth pin out 0 and 1. I leave below link to DealExtreme:
http://www.dx.com/pt/p/jy-mcu-arduino-bluetooth-wireless-serial-port-module-104299