http://www.cnx-software.com/2015/07/07/bbc-micro-bit-educational-board-features-an-arm-cortex-m0-mcu/    ARM Cortex M0 micro-controller (Nordic Micro nRF51822 Bluetooth SoC)    5x holes for 3V, GND, and 3 GPIOs    2x user buttons, 1x reset button    25x red LED indicator lights in a 5×5 matrix    Connectivity – Bluetooth LE    Sensors – Compass, magnetometer, accelerometer    USB – 1x micro USB port for port and programming    Power – 5V via USB or battery port to connect two AAA batteries    Dimensions – 4cm x 5cmou :http://www.numerama.com/magazine/33639-micro-bit-voici-le-concurrent-d-arduino-que-la-bbc-offrira-a-tous-les-enfants.html