VCC - 3.3VGND - GNDTXD - D12RXD - D11KEY - D13LED -That's it - Then you can connect to the bluetooth you desire. After you pair, the code is 1234 which may be changed by the AT commands.http://geekinc.ca/using-screen-as-a-serial-terminal-on-mac-os-x/http://www.instructables.com/id/Arduino-AND-Bluetooth-HC-05-Connecting-easily/?ALLSTEPS