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I am trying to create a Hierarchical block using the GNURadio Companion GUI. Answers I've found in other posts say to select the blocks you want to incorporate, then go to More -> Create Hier. Then a new screen is supposed to appear. However, doing "Create Hier" with any combinations of blocks selected seems to do nothing.

Am I doing something wrong, or is there a problem with my GRC?

HoosierPhysics
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1 Answers1

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It's very simple. You just start with a new flow graph in GRC, and use Pad Sources as input, and Pad Sinks as output.

If you want to let the user configure something, use a Parameter GRC block.

You must set the Generate Options in the Options block to Hier Block, and set a sensible ID there, too – don't stick with top_block, but use something (without spaces or -; it needs to work as a python name) that won't conflict with something else.

Here's an example:

a small hierarchical flow graph in GRC

You can then generate Generate button (or press [F5]), and then, after you've done a rescan of your block library with the refresh button Refresh Button you can find (and use) your new block in the Block Category you specified.

Marcus Müller
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  • Great! This clears things up nicely. I had read the official GNURadio wiki attempt to explain this, but it was much more convoluted. To be honest, your explanation here should make its way to the official site. – HoosierPhysics Oct 19 '16 at 17:03
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    Although this method completely works, it still doesn't use the "Create Hier" option under More when right-clicked. Is there an alternate method which incorporates that option? – HoosierPhysics Oct 19 '16 at 17:04
  • puh, good question. but: what exactly did you read? Did you go through http://tutorials.gnuradio.org ? – Marcus Müller Oct 19 '16 at 18:11