Re: [Discuss-gnuradio] raspi FAQ/HOWTO/recipe ??????

[Tom Rondeau]

On Wed, Apr 13, 2016 at 11:13 PM, Marcus D. Leech <address@hidden> wrote:

On 04/13/2016 11:05 PM, Jean Luc wrote:

I've been trying as well to use GR on RPi (model 3), the ultimate purpose would be radio astronomy. A smaller form factor such as RPI's makes a remote installation more palatable than a full PC.

I wasn't able to compile it on RPi but compromised on using a more recent version (3.7.9-3~bpo8+1) taken from jessie-backports. The steps are below.

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 8B48AD6246925553 7638D0442B90D010

sudo vi /etc/apt/sources.list and  add the following line:

deb http://ftp.debian.org/debian jessie-backports main

sudo apt-get update

sudo apt-get -t jessie-backports install gnuradio

On the positive side, GR works on RPi3. However, it does keep one core to 100% in many cases. This was with input from an SDR with the 2Msps rate, though. Actually, one more problem: audio output. That part didn't work ("check topology failed on audio_alsa_sink"); I posted a message on the list the other day. I cannot say it's a GR problem, could be mine; I have yet to understand what the problem is.

JL.

I'll point out that ARCH generally has up-to-date packages for this stuff, including for most of the ARM-based SBCs.

I run ARCH on various Odroid platforms, running radio-astronomy GR flow-graphs, with good success.  I run these "headless", without any
  graphical display from the Odroid--it's just the digital radio + processing platform.

We also keep information about our support and capabilities on embedded systems here:

http://gnuradio.org/redmine/projects/gnuradio/wiki/Embedded

Also for Android if you're running that on your embedded machine:

http://gnuradio.org/redmine/projects/gnuradio/wiki/Android

We don't have much posted on using RPis because, until recently, they were not an exciting platform for us. The initial RPi was so woefully underpowered as a processor that most of us trying to do actual math went with other solutions, like the Odroid that Marcus mentioned. With the RPi2 and RPi3, they now have interesting processors where GNU Radio makes a lot more sense.

Tom

 

On Wed, Apr 13, 2016 at 7:45 AM, Rob Roschewsk <address@hidden> wrote:

Marcus,

Thanks for responding.

I'm looking to build a headless FM receiver to record and stream public service communication (fire, police, etc.). We will stream as many channels as possible that fall into a given passband.

I already have a system running on a PC and now would like to port it to the PI.

I understand it maybe an "up hill" path, but the thought is to deploy multiple inexpensive units around a geographic area all feeding a central streaming server.

The Pi is running Raspian Jesse .... I started with the distribution packages but ran into problems right out of the blocks and thought it would be best to use the latest code before asking questions :)

I understand cross compiling is the way to go.

Since I brought it up, here was the error I saw when I tried to run the script that runs on the PC but fails spectacularly on the raspberry pi with the precompiled packages ....

address@hidden:~/sdr/multirx $ ./multirx_nogui.py -s 49 noaa.xml
linux; GNU C++ version 4.9.1; Boost_105500; UHD_003.007.003-0-unknown

high=162500000 low=162400000 span=100000
center=162450000
gr-osmosdr 0.1.3 (0.1.3) gnuradio 3.7.5
built-in source types: file osmosdr fcd rtl rtl_tcp uhd miri hackrf bladerf rfspace airspy 
Using device #0 Realtek RTL2838UHIDIR SN: 00000108
Found Elonics E4000 tuner
Exact sample rate is: 1000000.026491 Hz
Using Volk machine: generic_orc
VOLK: Error allocating memory (posix_memalign: 22)
VOLK: Error allocating memory (posix_memalign: 22)
VOLK: Error allocating memory (posix_memalign: 22)
Segmentation fault