anchor.diff:  set_direction(Pin, Direction) when Direction =:= in;
   				   Direction =:= out ->
       FileName = filename:join([?GPIO_BASENAME, ?PIN_NAME(Pin), "direction"]),
  -    debug(FileName, Pin),
  +    debug(FileName, Pin, {write, Direction}),
       ok = file:write_file(FileName, atom_to_list(Direction)).
       
   set_output(Pin) ->
  
positive.code: 
  -export([open_pin/1, close_pin/1]).
  -export([write_pin/2, set_pin_high/1, set_pin_low/1]).
  -export([set_direction/2, set_output/1, set_input/1]).
  
  -define(GPIO_BASENAME, "/sys/class/gpio").
  
negative.code: -define(DEBUG, false).
  
  
  debug(FileName, Pin, Operation) ->
      case ?DEBUG of
  	true  ->
  	    OperationString =
  		case Operation of
  		    read           ->
  			"Reading from";
  		    {write, Value} ->
  			io_lib:format("Writing ~p to", [Value]) 
  		end,
  	    io:format("GPIO pin ~p: ~s file ~p~n",
  		      [Pin, OperationString, FileName]);
  	false -> ok
      end.
  
  open_pin(Pin) ->
      FileName = filename:join(?GPIO_BASENAME, "export"),
      debug(FileName, Pin, {write, Pin}),
      case file:write_file(FileName, integer_to_list(Pin)) of
  	ok              -> ok;
  	{error, Reason} ->
  