Adafruit Bluefruit LE Shield - Bluetooth LE for Arduino The Bluefruit LE Shield makes it easy to add Bluetooth Low Energy connectivity to your Arduino or compatible. Solder in the included headers and plug right in. It connects to your Arduino or other microcontroller using the hardware SPI interface (MISO, MOSI, SCK) plus a chip select line (default D8), interrupt line (default D7) and reset (default D4). ARM Cortex M0 core running at 16MHz 256KB flash memory 32KB SRAM