anchor.diff:            start_link/2,
             register_int/1,
             set_int/2,
  +          read_bool/1,
             read/1,
             write/2,
             stop/1
  
positive.code: 
  
  %%
  %% Test Read the value of the GPIO pin
  %%
  -spec read(GpioRef :: pid()) -> 0 | 1 | {error, atom()}.
  
negative.code:                     'ok' | {'error', atom()}.
  
  set_int(GpioRef, Condition) -> gpio:set_int(GpioRef, Condition).
  
  
  %%
  %% Read the value of the gpio pin, return a boolean value
  %%
  -spec read_bool(GpioPinRef :: pid()) -> true | false.
  
  read_bool(GpioPinRef) ->
    case read(GpioPinRef) of
      1  -> true;
      0 -> false
    end.
  
  
  %%
  