Is it possible to create a block from other blocks?

GNU Radio
1

Hi all,

I wonder if there is a similar feature in grc as in Simulink where one
can
create a block from other blocks? (Select the blocks, right click and
merge
into one) Or how do you do more complicated flow graphs containing many
many blocks? I am a beginner and I already have a hard time fitting in
all
the blocks in the window of grc.

Best regards,

Carl

2

Yes.
https://gnuradio.org/redmine/projects/gnuradio/wiki/GNURadioCompanion#Hierarchical-Blocks

You can also increase the canvas size in the top block options.

On Tue, May 26, 2015 at 2:46 PM, Carl O. [email protected]
wrote:

Carl

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3

GRC has had the ability to create a hierarchical blocks for a little
while
(I forget which release added that): if you select multiple blocks you
can
right-click, and select more to find the ‘Create Hier’ option. This is
described on the wiki at:
http://gnuradio.org/redmine/projects/gnuradio/wiki/GNURadioCompanion#Hierarchical-Blocks

It is just creating another XML wrapper around the blocks to create the
hier block (with pads to allow input/output). I think usability wise it
is
essentially equivalent to the Simulink ‘merge blocks’ function.

Doug

On Tue, May 26, 2015 at 6:20 PM, Richard B. [email protected]

4

You can’t do it the way you asked specifically. The GUI functionality of
GNU Radio compared to Simulink is very different. The hierarchical block
mentioned by Chris above is a way of putting several blocks together
using
code to do the wrapping. You need to create a new block using gr_modtool
and wrap all the subblocks into this top block. It takes a lot more
experience to do then the few simulink clicks. If you’re are not afraid
of
that and plan on using gnuradio long term, it’s worth learning how to
do.

Rich

On Tue, May 26, 2015 at 3:14 PM, Chris K. [email protected]

5

You don’t need to code to create hier blocks; they can be created and
used purely within GRC.

On Tue, May 26, 2015 at 3:20 PM, Richard B. [email protected]
wrote:

On Tue, May 26, 2015 at 3:14 PM, Chris K. [email protected]

Best regards,

–
GDB has a ‘break’ feature; why doesn’t it have ‘fix’ too?

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6

Scrolling back I see I missed a little bit of the earlier discussion -
so
to elaborate a little:

Simple ‘merging of blocks’ (i.e. I have several blocks connected
together
in a particular way, and want to wrap that up to re-use in other places)
is
what GNURadio refers to as a hierarchical block. The blocks are being
re-used (to avoid duplication of code, which all programmers learn to
hate
the second time they copy and paste code and then have to go back and
fix
bugs in both places), but not being modified: and their connections are
static.

If you want to use the functionality of several blocks and not have a
static flowgraph (e.g. I want to access particular functions of
particular
blocks, but in some dynamic fashion that is not easily rendered as a
static
flowgraph), then you would want to do as Richard suggests: create your
own
out-of-tree module with custom blocks. For what I would consider to be
any
advanced functionality (i.e. application-specific function that is more
than just a custom flowgraph) this is going to be required. That said -
there is a fairly large set of things that you can do within the static
flowgraph framework - and you can certainly spend a long time developing
applications entirely within GRC before you need to go down the path of
creating custom blocks. Since the amount of things you will need to
learn
at that point greatly increases, I suggest holding off until you know
for
sure this is what you need.

Doug

On Tue, May 26, 2015 at 6:33 PM, Douglas G. <

7

Oh I take it back then. I did not know about this functionality myself.
Good to know!

Rich

On Tue, May 26, 2015 at 3:41 PM, Chris K. [email protected]

8

Thank you for all the answers!

I will try the different solutions.

Best regards,

Carl

On 27 May 2015 at 00:42, Douglas G. [email protected]