anchor.diff:  map_attr([default]) ->
       0.
   
  +index(gpio1) ->
  +    0;
  +index(gpio2) ->
  +    4;
  +index(led1_r) ->
  +    8;
  +index(led1_g) ->
  +    9;
  +index(led1_b) ->
  +    10;
  +index(led2_r) ->
  +    11;
  +index(led2_g) ->
  +    12;
  +index(led2_b) ->
  +    13;
  +index(jumper_1) ->
  +    14;
  +index(jumper_2) ->
  +    15;
  +index(jumper_3) ->
  +    16;
  +index(jumper_4) ->
  +    17;
  +index(jumper_5) ->
  +    18;
  +index(spi1_pin9) ->
  +    19;
  +index(spi1_pin10) ->
  +    20;
  +index(ss1) ->
  +    21;
  +index(ss2) ->
  +    22;
  +index(Any) when is_integer(Any) ->
  +    Any.
  +
  
positive.code:     configure(Port, Pin_index, Type, [default]).
  
  configure(Port, Pin_index, Type, Attr) ->
      Port ! {self(), {command, <<Pin_index:8, 1:8, 
  				(map_type(Type)):8, (map_attr(Attr)):8>>}}.
  
  configure_gpio(Port, gpio1, {T1, T2, T3, T4}) ->
  
negative.code: 
  % API
  -export([open/0, configure/3, configure/4,
  	 configure_gpio/3, get/2, clear/2, set/2, set/3, clear/3,
           enable_spi_ss1/1, disable_spi_ss1/1]).
  
  %--- API -----------------------------------------------------------------------
  
  