Re: [Discuss-gnuradio] [USRP-users] GNU Radio flow graph code

[Marcus Müller]

Hi Alejandro,

please always ask on the list!

GNU Radio companion only generates a single python file containing the
definition of your flow graph.
This flowgraph consists of connected blocks, of which the USRP UHD
sink/source is capable of communicating using UHD.
Its source code can be found in gr-uhd.

As you can see, I think there's a bit of misconception on how a GNU
Radio application works; so you might want to read up on the beginners'
tutorials, especially "what is GNU Radio (and why do I want it)" and
writing your first python application on gnuradio.org.
See my notes in your text below :)

Greetings,
Marcus

On 14.07.2014 22:12, alejandro kilei wrote:
> I've been searching through the Python files that GNU Radio Companion uses,
> especially those located in the uhd directory.
GRC doesn't use any of these; it just uses the XML block definitions to
build the flowgraph python executable.
>  I'm a bit confused how GNU
> Radio Companion interfaces with the UHD. 

Not at all, it just connects the UHD source/sink with the rest of your 
application, and doesn't care what happens inside that block.

> Do you know which file UHD is
> instantiated? 
UHD is a library; you don't instantiate it. You get an instance of the
usrp_sink or _source, which are GNU Radio blocks.
> Also, along the same lines, does GNU RC
We call it GRC, or GNU Radio companion; GNU RC is just too confusing, as
GNU is a *huge* project, and GNU Radio is but one GNU project of
hundreds, of which the GNU Radio Companion is but a graphical user
interface.
>  open a file for UHD
> data and then close it, 
UHD is a library! You get UHD device objects, which have streamer
objects, which have recv() and send() methods. For UHD documentation,
google for Ettus UHD doxygen.
> or does it make a FIFO, or does it do something
> else (the file where this happens would also be helpful)?
Look at the gr-uhd/lib/*.cc files, or if you want something that uses
UHD but isn't part of the (complex) GNU Radio framework, look at the
examples that come with the UHD source code.
> Thanks for the help
> Alejandro
>
>
> On Mon, Jul 14, 2014 at 12:06 PM, Marcus Müller <address@hidden>
> wrote:
>
>>  When generating the code, in the console window you see something like
>> Generating: "/home/marcus/test_oom.py"
>> This is the python file GNU Radio Companion generates.
>>
>> Greetings,
>> Marcus
>>
>> On 14.07.2014 20:03, alejandro kilei via USRP-users wrote:
>>
>> How do you view the code generated by the GNU Radio GRC flow graph? I
>> partly need to know how GRC interfaces with UHD and also need to make some
>> custom edits within the code generated by the flow graph.
>> Thanks for the help
>> Alejandro
>>
>>
>>
>>
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