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,