블루푸루트 LE 프렌트 블루투스 4.0모듈/ Bluefruit LE Friend - Bluetooth Low Energy (BLE 4.0) - nRF51822 - v2.0 
The Bluefruit LE Friend is your new BLE BFF! This USB-to-BLE board makes it easy to get your computer talking to your BLE enabled phone or tablet using a standard serial/UART connection.
In it's simplest form, it works on the same principle as a common USB/Serial adapter (the FTDI Friend, for example!). Any data that you enter via your favorite terminal emulator on your development machine will be transferred over the air to the connected phone or tablet, and vice versa, as a basic 'UART' connection
The short and sweet:
Completely transparent Data mode for USB to Bluetooth LE UART connectivity from computer to tablet/phone
Connect to any phone or tablet with BLE, great for debugging or developing BLE devices or apps
Uses the fancy Nordic nRF51822 chipset with custom firmware
Optional Command mode to set GATT services/characteristics, advertising name/packet, Beacon capability, query status, RSSI, etc.
Comes with standard Over-the-Air DFU bootloader, reprogram firmware using any BLE-capable iOS or Android device
4 LED indicators: blue connection status, red mode status, orange and green for RX/TX
Snap-off SWD connector for advanced JTAG re-programming
Comes with Nordic nRF58122 developer key
You might be asking,Hey my macbook already has Bluetooth and I can get a USB Bluetooth adapter, so why use this?Good question! You can get aBluetooth 4.0 USB dongle from the store already, but Windows 7 doesn't support Bluetooth Low Energy natively, and on Win8 or OS X you'll have to sort through a huge pile of native Bluetooth APIs and development tools that often require an annual paid license and specific license terms to access. You can't just connect wirelessly without a huge stack of software or firmware in the way because there isn't a standard, open source, cross-platform way to talk BLE today.
The Bluefruit Friend is much more, it has a full BLE peripheral stack and interface software so that you can treat your BLE connection just like a UART connection - that makes it trivial to use with free Terminal software or scripting software like python (with pySerial). Using Bluefruit LE Friend, you can be up and running in under and hour on just about anything with a USB port, with easy migration across platforms and operating systems.
To use, simply plug into your computer and flip the switch to eitherUARTmode (transparent data transfer, anything you type will be sent, and data from phone is received as well) orCoMmanDmode, where thanks to an easy to learn AT command set, you can also create you own basic GATT Services and Characteristics, simulate Beacons, and change the way that the device name appears/advertises itself.
To make sure that your device stays up to date and can benefit from the latest Bluefruit LE firmware from Adafruit, you can also update the firmware on your BLEFriend over the air using any BLE-supported iOS or Android device. We always try to keep the bar as high as possible at Adafruit, and one of the biggest advantages of the BLEFriend and the entire Bluefruit LE family is that we wrote and maintain all of the firmware running on the devices ourelves from scratchand we'll be releasing new firmware and bug fixes without having to rely on a third-party vendor. For super-advanced users, we have an SWD connector on board that can be used to reprogram the nrf51822 using Nordic's SDK and an SWD debuggerlike the J-Link.
As of July 29th, 2015 we're selling an updated version with a black PCB and the nRF51822 module with 32KB of SRAM. This version is backwards compatible with previous versions and can also be used with theAdafruit Bluefruit LE firmware v0.6.2 and higher.If you have the blue PCB version, that is 16KB and you can only go up to v0.5.0 due to RAM limitations.