/**
  \example helloworld.cpp 

  A program that prints 'Hello world' is a traditional first program
  in 'big computer land', kind of like the basic blinky except for
  computers that don't have LEDs..

  Now, the traditional helloworld program prints "Hello world" once,
  and then exits.  But of course, for a 'physical computation' machine
  like ours -- living in the wild, out in the real world -- exiting
  makes no sense at all.

  When you think about it that way, maybe the traditional program
  should really be called 'Goodbye world'.

  This sketch uses traditional serial communications, connecting at
  9600 baud 8N1, to print 'Hello world' to the NorthFace every ten
  seconds.  Now that's polite,

 */
