Hello,
I am new to gnuradio, and I felt confused with “glue the blocks”, such
as
hier_block2.
I have read gnu tutorial by Mr. Shen and I understood there were
multiple
attributes to describe a block, such as endpoint and edge.
But when I tried to analyze an example of code, there was no such block
of
code to elaborate on
them. I cannot understand how python knows how to connect between two
blocks.
Which signal plays as input or output to connect between them? And am I
able
to use only line-by-line code to replace partial usage of glue(
top_block.connect(block1,block2)) ?
p.s I thought this should be a preliminary question. There must be
something seriously wrong with my concept. Please correct it if you
don’t
mind spending some time typing.
Thank you all
Hi,
The simplest examples that you can look at to understand about gnuradio
can
be found at this website.
http://www.joshknows.com/gnuradio
Think of gnuradio as a system of blocks that perform unique functions.
Each
of these blocks will either behave as a sink or a source. Your job is to
find which of these blocks do the work for you. Once you identify these
blocks you must connect them to so as to make the output of one block be
the
input of the next hierarchical block.
We no longer use hier_block. If you look at the new examples its called
top_block. It’s the same thing but with a new name. hier_block or
top_block
means the overall system that you are building which makes use of other
blocks inside of it.
As a beginner you need not understand how the connect and run do things
for
you. When you call “connect” think of it as telling a block to pass its
output to the next block in hierarchy as its input. And calling “run” as
telling your implemented system to start doing its work. Just assume
that
whatever they do is perfectly done and all you need to worry about is
how
can you implement your system with the blocks that you already have in
gnuradio or you may implement your own blocks in C++. To learn how to
make
blocks look at the tutorial in your gnuradio installation. Its found in
“gnuradio/gr-howto-write-a-block” directory.
Take a look at the examples in /usr/local/share/gnuradio/examples
directory.
I started with examples in “audio” directory and “digital” directory.
Understanding of benchmark_tx and benchmark_rx in digital directory
according to me is of prime importance.
I say it again. Don’t worry about how python knows about connect and
run.
Trying to know this will take you a lot of time. Begin with
understanding
what Gnuradio actually accomplishes. Once, you get the feel of this you
can
spend time understanding how the scheduler and other intricate stuff
works.
Take a look at documentation about USRP. Understanding of things that
happen
in a usrp is essential too.
http://rapidshare.com/files/121692530/USRP_Documentation.pdf
This is what I did as a beginnner and it took me a lot of time to
understand
gnuradio. Even though I don’t understand it as good as others on this
list
do but still I am comfortable working with it. Even to this date I
didn’t
spend time on understanding how run/connect work as I never felt it was
necessary to do so. I believe in “Why reinvent the wheel?” philosophy
and I
am happy with it.
Good Luck
Ali