Where to Start?

GNU Radio
1

Hello,

I am using the USRP(1): is there a better place to start than the
“exploring
gnu radio” page here:
http://www.gnu.org/software/gnuradio/doc/exploring-gnuradio.html

It has many problems as you know. I found a page on joshknows.com:
http://www.joshknows.com/gnuradio

…this clears up the gr.flow_graph() error (should be gr.top_block() ),
but
can find no info on getting the mc4020 FM tuner example to work. That
is a
shame as it was interesting. I’m not sure where to go.

For now I will continue reading this and then try the “how to write a
signal
block” page.

My ultimate goal is to emulate 802.15.4 in USRP (which has been done
before)
and test some variations in the MAC layer. For now, I just need to
learn
gnuradio though!

-Dave

2

On 07/09/2011 04:35 PM, dave wrote:

can find no info on getting the mc4020 FM tuner example to work. That is a
shame as it was interesting. I’m not sure where to go.
The MC4020 example was unrelated to USRP1 in any way as far as I know.
It was for a piece of
hardware someone was playing with years ago.

For now I will continue reading this and then try the “how to write a signal
block” page.

My ultimate goal is to emulate 802.15.4 in USRP (which has been done before)
and test some variations in the MAC layer. For now, I just need to learn
gnuradio though!

-Dave
Many thought experiments can be conducted using Gnu Radio Companion
(GRC), which gives you a graphical, Lego-Like
way of assembling and re-assembling flow-graphs.

You could start here:

http://www.csun.edu/~skatz/katzpage/sdr_project/sdr/grc_*tutorial*1.pdf

3

Ok, I will look into using the GRC as a first step.

I am hoping to work with the USRP eventually. If someone knows some up
to date tutorials specifically for USRP that would be appreciated as
well.

I see now that the mc4020 code was intended to gather the FM from a
cable modem over a parallel port. That is not general code or USRP code
at all.

The info at: Josh Knows | Introductory Tour of the GNU Radio Project …does have some
gnuradio + USRP specific code, but it’s very short. Maybe I can figure
it out by looking at that along with the “how to write a signal block”
page.

Thanks,
Dave

On Sat, 09 Jul 2011 17:21:52 -0400, Marcus D. Leech wrote

On 07/09/2011 04:35 PM, dave wrote:Hello,

I am using the USRP(1): is there a better place to start than the
“exploring
gnu radio” page
here:
http://www.gnu.org/software/gnuradio/doc/exploring-gnuradio.html

It has many problems as you know. I found a page on
joshknows.com:
Josh Knows | Introductory Tour of the GNU Radio Project

…this clears up the gr.flow_graph() error (should be gr.top_block() ),
but
can find no info on getting the mc4020 FM tuner example to work. That is
a
shame as it was interesting. I’m not sure where to
go.
The MC4020 example was unrelated to USRP1 in any way as far as Iknow.
It was for a piece of

hardware someone was playing with years ago.

For now I will continue reading this and then try the “how to write a
signal
block”
page.

My ultimate goal is to emulate 802.15.4 in USRP (which has been done
before)
and test some variations in the MAC layer. For now, I just need to
learn
gnuradio
though!

-Dave
Many thought experiments can be conducted using Gnu Radio
Companion(GRC), which gives you a graphical, Lego-Like

way of assembling and re-assembling flow-graphs.

You could start here:

http://www.csun.edu/~skatz/katzpage/sdr_project/sdr/grc_tutorial1.pdf

–

Marcus
Leech
Principal
Investigator
Shirleys Bay Radio Astronomy
Consortium

4

On 07/09/2011 05:59 PM, dave wrote:

The info at: Josh Knows | Introductory Tour of the GNU Radio Project …does have some
gnuradio + USRP specific code, but it’s very short. Maybe I can
figure it out by looking at that along with the “how to write a signal
block” page.

Thanks,
Dave

What you’ll find is that you won’t need to write your own signal
processing blocks, at least, not intially. GRC (also known as
gnuradio-companion on recent releases) contains many of the
fundamental building blocks necessary to construct fairly
sophisticated radio systems.

Also, GRC produces python code, which you can inspect and learn from.

5

Well, I have not been able to get GRC to actually run. I had setup two
machines with Ubuntu 11.04 by installing the UHD package from
ettus.com. With that, I have gotten some basic programs to run (dial
tone), but typing ‘grc’ shows the command as not found.

Attempts to install GRC via package first resulted in a version
conflict. A google search suggested I install clean so I did that
(installing without the UHD) and instead got a bunch of python errors.
I did all that on the second machine… the first one still has the UHD
installation that is not messed with.

Doesn’t the GRC come with the UHD package? If so, where is the binary
(or python script) located? Maybe it will work from the UHD install
without any other modifications.

I found the mailing list archive at ruby-forum.com, so I’m checking
other threads now. This is really frustrating!

David

On Sat, 9 Jul 2011 18:35:23 -0500, dave wrote

–

Marcus

Leech
Principal

Investigator
Shirleys Bay Radio Astronomy

Consortium

6

On 07/09/2011 08:36 PM, dave wrote:

Doesn’t the GRC come with the UHD package? If so, where is the binary
(or python script) located? Maybe it will work from the UHD install
without any other modifications.

I found the mailing list archive at ruby-forum.com, so I’m checking
other threads now. This is really frustrating! **

David *
*GRC is part of Gnu Radio, not UHD. UHD is just a driver package for
Ettus hardware that interfaces with Gnu Radio through
gr-uhd.

A good way for newbies to install Gnu Radio + UHD is to use my “does
everything” script:

http://www.sbrac.org/files/build-gnuradio

This script downloads and builds everything from the latest source,
including installing pre-requisites, deleting anything that might
be in conflict from a binary-packages install, and also downloads the
latest firmware for the Ettus USRP hardware.

Also, due to naming conflicts, GRC is actually invoked using the
“gnuradio-companion” command.

7

2 things:

  1. Install from source. Dont install the debian packages from apt,
    they are ancient and will mess with your source install

  2. The executable is called gnuradio-companion
    http://gnuradio.org/redmine/projects/gnuradio/wiki/GNURadioCompanion#Execution

-Josh

8

Thanks for the information. I’ll focus on the GRC for now then.

David

On Sat, 09 Jul 2011 18:13:20 -0400, Marcus D. Leech wrote

What you’ll find is that you won’t need to write your own signalprocessing
blocks, at least, not intially. GRC (also known as
gnuradio-companion on recent releases) contains many of thefundamental
building blocks necessary to construct fairly
sophisticated radio systems.

Also, GRC produces python code, which you can inspect and learnfrom.

–

Marcus
Leech
Principal
Investigator
Shirleys Bay Radio Astronomy
Consortium

9

I was already using Marcus’ build script, but I just found about the
correct name for the gnuradio-companion command in a thread from a few
weeks ago. Not sure how I missed that!

I have run it and the program works fine now. I was afraid I wouldn’t
be able to do anything useful for days. :slight_smile:

Many thanks!

David