dear list,
I'm new here.
I'm developing a pd&software-defined radio project for a sound-art installation using rpi.

I'm trying to get purr-data working in order to obtain some software-defined radio functions into a patch. In particular I like the idea of detecting in pd the RF field, and usign radio signals as an input and as a kind of invisible/inaudible landscape (since it is not demodulated).

Tom Zicarelli developed an rtlsdr~ object

[https://github.com/tkzic/pd-rtlsdr](link url)

he says that it should be used with pd-extended but currently I'm not able to run pd-extended in rpi

the patch he put as an examle "rtlSDR-block.pd" seems to open perfectly for every object but rtlsdr~

I'have put all the rtlsdr~ files into the extra folders, but purr-data cannot create it anyway

does anybody could help me in doing this trick?

Any help is greatly appreciated!

love for your great work

stefano

@stefano_zorzanello you might need to install a package called librtlsdr0.
rpi uses apt, yes? if so, then type this into a terminal window:

apt install librtlsdr0

Thank you very much myQwill for your answer!
I followed your tip, installed the librtlsdrO (zero) but nothing changed... I think tht the problem remains in the external [rtlsdrì~] that needs to be compilerd, and I don't know how to do that...

I put again here the Zicarelli git-hub repository

[https://github.com/tkzic/pd-rtlsdr](link url)

if anyone could help it's very much appreciated.

best
stefano

@stefano_zorzanello My bad, I must not have realised that when I was testing this on my computer, I actually did end up recompiling as well. I thought maybe it hadn't built successfully.

To compile, just open up src/pd/linux/rtlsdr~ in a terminal and type make

@myQwil Sorry, my bad again, I actually did not recompile, everything started working on my end as soon as I installed librtlsdr0

However, now I have gotten it to compile, and I needed to install the dev package to get it to work. So in the terminal you would write:

apt install librtlsdr-dev

and now when you try running make, it should build successfully

thank myQwil again, I've installed the stuff you told me with

apt install librtlsdr0

apt install librtlsdr-dev

the following lines are the report from terminal

pi@raspberrypi:~ $ sudo apt install librtlsdr0
sudo: /etc/sudoers.d is world writable
[sudo] password for pi:
Reading package lists... Done
Building dependency tree
Reading state information... Done
librtlsdr0 is already the newest version (0.5.3-11+rpt1).
The following packages were automatically installed and are no longer required:
coinor-libipopt1v5 libbluray2 libmicrodns0 libmumps-seq-4.10.0 libraw15
Use 'sudo apt autoremove' to remove them.
0 upgraded, 0 newly installed, 0 to remove and 1 not upgraded.
pi@raspberrypi:~ $ cd /usr/lib/pd/extra/pd-rtlsdr-master/src/pd/linux/rtlsdr~
pi@raspberrypi:/usr/lib/pd/extra/pd-rtlsdr-master/src/pd/linux/rtlsdr~ $ make
make: Nothing to be done for 'pd_linux'.

then I replaced the new [rtlsdr~.pd_linux] into the extra folder, but pd still couldn't create the object

one qustion does it work fo you with purr-data or just pd?

thank you for your patience...

best
stefano

@stefano_zorzanello It works on purr-data for me. Try this though: instead of writing make write make clean; make

Great myQwil!
by your kind advice i COULD MAKE IT WORK! Now, replacing the rtlsdr~.pd_linux object with the newly created one in their externals folder, both pd-vanilla and purr-data do create rtlsdr~

!

I'm so happy that my project can start from here.

Just in purr-data at the moment I can't get the audio work because of some errors that I don't understand:

here's the console report only error at start-up

libdir_loader: added 'pdlua' to the global objectclass path
tried but couldn't sync A/D/A

and then when I put the dsp on I get

error: audio I/O dropout (with a red numerical index in brackets increasing each 5/6 seconds, or so)

the dsp is working as I can see the audio signal operating, but no audio from the dac

I can't find also any place where to set the usb sound card I'm using with rpi

any idea?

anyway, at least pd-vanilla works fine and this is most important thing.

thank you again
best
stefano

@stefano_zorzanello Someone seems to have had a similar issue in this thread: https://forum.pdpatchrepo.info/topic/11606/audio-io-error-couldn-t-sync-a-d-a