Re: [Discuss-gnuradio] Souce Block

[Eric Blossom]

On Wed, Aug 25, 2010 at 10:08:22AM -0300, John Li wrote:
> Hi!
> 
> I have many source blocks with different kinds of signal generator and I
> want to create a configurable unique block.
> 
> Can I make a source block with multiple outputs each one with a different
> rate?
> 
> Thank you,
> John

Yes you can in 3.3.*

Your block will need to derive from gr_block, and in general_work you
must call produce for each output streams, and general_work must
return WORK_CALLED_PRODUCE as it's value.

>From gr_block.h:

  //! Magic return values from general_work
  enum {
    WORK_CALLED_PRODUCE = -2,
    WORK_DONE = -1
  };

  ...

  /*!
   * \brief Tell the scheduler \p how_many_items were produced on output stream 
\p which_output.
   *
   * If the block's general_work method calls produce, \p general_work must 
return WORK_CALLED_PRODUCE.
   */
  void produce (int which_output, int how_many_items);


Eric