# define the used CPU
  export CPU = nrf51
  export CPU_MODEL = nrf51x22xxaa
  
  # define the default port depending on the host OS
  PORT_LINUX ?= /dev/ttyUSB0
  PORT_DARWIN ?= $(firstword $(sort $(wildcard /dev/tty.SLAB_USBtoUART*)))
  
  # setup serial terminal
  include $(RIOTBOARD)/Makefile.include.serial
  
  # this board uses openocd
  include $(RIOTBOARD)/Makefile.include.openocd