Evaluate GNU Radio application performance on Pi4(2G)

I used Gnu Radio GUI to generate a Python program for audio_QTv1.grc from the gnuradio.zip file.  The generation went fine.  But, these issues are apparent:

(1) The generated code used the print syntax of Python 2.  This was easily fixable.

(2) There are no Python 3 libraries as a result of the installation (apt install gnuradio).  I could only find gnuradio packages in /usr/lib/python2.7/dist-packages/gnuradio.

(3) For those of you who use Anaconda instead of pip/pip3 to maintain your packages, this is probably a show stopper.

Note that Python 2 is deprecated as of 2020-01-01.  Many developers are in the process of migrating to Python 3, particularly in scientific communities.

So, if you want Python 3 support, do not do this immediately:  sudo apt-get install gnuradio

Instead, use the PPA methodology first as described on https://wiki.gnuradio.org/index.php/InstallingGR#Ubuntu_PPA_Installation and then:  sudo apt-get install gnuradio

I used Gnu Radio GUI to generate a Python program for audio_QTv1.grc from the gnuradio.zip file.  The generation went fine.  But, these issues are apparent:

(1) The generated code used the print syntax of Python 2.  This was easily fixable.

(2) There are no Python 3 libraries as a result of the installation (apt install gnuradio).  I could only find gnuradio packages in /usr/lib/python2.7/dist-packages/gnuradio.

(3) For those of you who use Anaconda instead of pip/pip3 to maintain your packages, this is probably a show stopper.

Note that Python 2 is deprecated as of 2020-01-01.  Many developers are in the process of migrating to Python 3, particularly in scientific communities.

So, if you want Python 3 support, do not do this immediately:  sudo apt-get install gnuradio

Instead, use the PPA methodology first as described on https://wiki.gnuradio.org/index.php/InstallingGR#Ubuntu_PPA_Installation and then:  sudo apt-get install gnuradio

With the newer version of GRC, it generated a Python 3 version of top_block.py that worked fine the first time.

Can i get some clarification. I feel like we are both flying around the same light bulb seeing something different.

• How are you installing GRC (i.e. GNU Radio). apt-get or compiling?
• What version of GRC is reported within the application?
• I understand the python version relationship. I thought a 3.8 install of GRC was Python3 and Python 2 was gone. Is this correct?
• I am seeing differences in GRC version depending if the load is for a Pi or say a Ubuntu Linux. You suggest a newer version of GRC will produce a top_block for the audio flow graph without errors. That has not been my experience as late as my last post. What do you believe is a new version of GRC?

This post I stumbled across https://github.com/lutusp/PLSDR/issues/6  alludes to a similar error code. It is pretty general on the problem description but rings to an audio configuration problem with the application. I'm thinking GRC is expecting a particular audio configuration on the Pi that is not there generating the error. The work around of establishing a bluetooth configuration puts in place a audio configuration GRC can use. I wish I was more familiar with Pi audio architecture but I work with what I have.

I do like your thought process and would like to continue the discussion. My goal is to establish a consistent process for a Pi GRC installation. The process would give you the ability to verify the install to say this should work.

Sean

My premise is that I will no longer use Python 2 since it is deprecated; all of my projects are now converted to Python 3.  What I described previously was what I did for an x86/x64 APT-based Linux system like one of the *buntus or debian.  On my Xubuntu x64 build, it worked perfectly.  Clearly, this is not appropriate for a Raspberry Pi.  So, I'll see what I can do on my Raspberry Pi 3B (don't have a 4 yet) which boots and runs from a USB disk (relief from using a MicroSD which I highly recommend!).

This is what I found for the Raspberry Pi: https://wiki.gnuradio.org/index.php/InstallingGRFromSource_on_Raspberry_Pi which leads you to https://wiki.gnuradio.org/index.php/InstallingGR#To_install_system_wide as part of installation.

I did this because the existing Raspbian Buster does not yet have a Python 3 oriented package for gnuradio; this is a "build from (github source") exercise.  Certainly, gnuradio 3.8.0 (latest github version) will eventually find its ways into all of the repositories.

On a Raspberry Pi 4, building from source is MUCH faster, I would imagine!

If you are not worried about excess heat and freezing up, when you get to the `make` step, use the -j parameter for specifying more than one CPU cores.  I used `make -j3 # 3 CPU cores` since my Pi is otherwise idle at the moment.  It feels cool to the touch but, then again, it is not a Pi 4.

Version: The CHANGELOG.md file on github indicates that this is [3.8.0.0] - 2019-08-09.

Python flavor: I selected Python 3 per instructions (recommended). I did not try Python 2.

Differences in GRC between Pi and Ubuntu: Going to be looking out for this.  Thanks for the heads up.

Begin make step at 13:25 USA CT.  I'll report when the make step ends. Time for tea and scones.

At 14:05 USA CT (40 elapsed minutes), I am 33% of the way through the make (compiles).  So, my estimation is that this will take 120 minutes from start to end on a Raspberry Pi 3B with a USB disk and using 3 of its CPU cores.  In theory, I should be done around 15:25.

CPU Speed 1200 Mhz | CPU Temp 85 °C

Your description confirms to me, that you flying around a different light bulb that I am.  I'm going to avoid flying off to your bulb and stick to my current light source.

Raspbian Buster 2019-09-26 full image loads GNU Radio companion (GRC) 3.7.13.4.

Ubuntu 18.04 loads GRC 3.7.11.

Both installs are accomplished with an apt-get install gnuradio. I discovered the Raspbian version comes up short in how it is packaged. It doesn't support SDR devices. You must perform an apt-get install gr-osmosdr to get the SDR source blocks. This is not required on the Ubuntu install.  I'm not going to go down the rabbit hole of why there are differences.

The problem under analysis is poor audio from GRC on a Pi3B+. On Christopher's cstanton install, using the package manager he experienced an error, that prevented the flow graph from running. I found a kludge to work around the error by configuring the Pi to support Bluetooth audio. With the Kludge in place the Pi3B+ appears to work and the audio is acceptable using the audio flow graph. My RTL/SDR is on loan at the moment so I can confirm if the Pi GRC install works.

I am hoping the GRC audio issue error message is a simple ALSA audio configuration issue. My scuba tanks are not sufficient to explore that depth at the moment.

I would be curious to discover if a compiled version of GRC gets the same error Christopher experienced. To have confidence in the results, the Pi O/S must be pristine (i.e. nothing install but GRC) because it has been demonstrated loading other applications that configure audio can and do screw other applications running on the Pi.

Sean

Lucky for me that I am not interested in outgoing audio.  My personal interest is in processing incoming electromagnetic radiation in the radio band.

On *buntu x86/x64, you can use the PPA method (simple) that I described earlier of getting gnuradio 3.8.0 (Python 3) until it finds its way into the main repos.  Once installed, maintaining updates is the same with any *buntu package through APT.  So, its an Ubuntu PPA temporarily versus being stuck on Python 2.  Pick yer poison.

Have you folks seen this RPi4-related gnuradio graphics and performance bug report?  https://github.com/gnuradio/gnuradio/issues/2848

Only 68% done and still running!  This is why I drive project managers crazy.

It must have finished very late.  I went to bed around 22:00 USA CT.

This morning, I ran `make test`.  Out of 362 tests, all passed except the following:

149 - qa_pmt (Failed)

347 - qa_qtgui (Failed)

358 - qa_zeromq_pub (Failed)

359 - qa_zeromq_pubsub (Failed)

360 - qa_zeromq_pushpull (Failed)

361 - qa_zeromq_reqrep (Failed)

362 - qa_zeromq_sub (Failed)

No errors finishing up:

sudo make install

du -ks /usr/local

322224 /usr/local

So, plan on adding 322 MB with this build in addition to the 700 MB needed in the source directories for `make` executions.

The gnuradio version is 3.9.0.

Unfortunately, there seems to be no gnuradio-companion as a result of this build.  I looked all over my disk.

Ran sudo make uninstall and now I am trying the pybombs method as described on the gnuradio github page.