Adafruit Bluefruit LE UART Friend - Bluetooth Low Energy (BLE)

The Bluefruit LE UART Friend makes it easy to add Bluetooth Low Energy connectivity to anything with a hardware or software serial port. The board is capable of much more than just sending strings over the air. Thanks to an easy to learn AT command set, you have full control over how the device behaves, including the ability to define and manipulate your own GATT Services and Characteristics, or change the way that the device advertises itself for other Bluetooth Low Energy devices to see. You can also use the AT commands  to query the die temperature, check the battery voltage, and more, check the connection RSSI or MAC address, and tons more.

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