\ button.txt to Demo Digital input      DaR 2014-02-17
chop-button
marker chop-button
4 value buttonPin \ Use digital pin 12 for the button pin
: states ( --- read state of button )
   PortB buttonPin 2dup PoBiIn  PoBiRead
   begin  PortB buttonPin PoBiRead  2dup - if
         cr ." The button state is "  dup . swap
   then  drop  ?key until  drop ;
flush