+ FiveD on Arduino implements a watchdog, which has to be reset every 250ms or it will reboot the controller. As rebooting (and letting the GCode sending application trying to continue the build with a then different Home point) is probably even worse than just hanging, and there is no better restore code in place, this is disabled for now.
+// #define USE_WATCHDOG
analog subsystem stuff
REFERENCE - which analog reference to use. see analog.h for choices