Nordic Semiconductor nRF51 Development Kit board (PCA10031).

• Debug Interfaces
  J-Link	USB

• Core features
  Other Core Feature	1 x Bluetooth Low Energy (Bluetooth Smart) support
  Other Core Feature	1 x ANT/ANT+ support

• Debug
  Integrated Debug Adaptor	1 x On-board J-Link

• Other
  Crystal Oscillator	16 MHz Crystal Oscillator
  Crystal Oscillator	32.77 KHz Crystal Oscillator
  Other Feature	1 x mbed Enabled
  Other Feature	1 x On-board PCB antenna

• Power
  Power Supply	5 V - 0 V USB Powered
  Power Socket	1 x USB

• Connectors
  USB	1 x USB

• Display
  LEDs	3 x RGB LEDs