Using a USB (or PiSound) Audio Interface?

[ElRay70K70H]

I have an RPi4 that was setup to use the MODEP code, but their codebase is all 32-bit and light on plugins. The new 64-bit (beta) piStomp script & code seems a better choice; however, I don't have any of the preconfigured PiHats. What I do have is a PreSonus USB interface can that be used? Is it an automatic configuration, or simply a JACK configuration?

I also have a PiSOUND hat, but I'd rather not deal with installing it's drivers, etc. for this initial stab at the piStomp codebase.

[Randall (Admin)]

The 64-bit pi-Stomp is not on mainline so no longer considered beta.  Yes, the 64-bit with realtime kernel is more performant and adds so many cool plugins not available via 32-bit MODEP.

We provide automatic configuration of the 3 ADC/DAC cards (IQAudio Codec Zero, HifiBerry DAC+ADC and AudioInjector cards).  You'd need to configure jack/alsa to use your PreSonus USB, but there's nothing specific in the Jack requirements for pi-Stomp/MOD, so if you can get it (or any ADC/DAC) to work on your system, it should work just fine with pi-Stomp. 

[ElRay70K70H]

Thanks!

I've already made a start and I'm at the point where I need to configure JACK, because the service immediately stops.

I ran into some trouble (I don't recall what) running setup.sh, so I ran the individual scripts inside. I did run into a few issues because the scripts assume:

• The user running the scripts is: pistomp
• The user's home directory is: /home/pistomp
• The source code/build directory is: /home/pistomp/pi-stomp

I almost always do builds like this under: /usr/local/src and I was logged in as "me".

As I type this, I suspect the issue w/ setup.sh was path-related and will likely run now.

[Randall (Admin)]

Right.  As stated in bold in the installation instructions (https://www.treefallsound.com/wiki/doku.php?id=software_installation_64-bit), the user name must be pistomp.  If you choose otherwise, then yeah, you're on your own.

[ElRay70K70H]

As stated in bold in the installation instructions ... the user name must be pistomp

Yeah, I totally skipped the section on writing a microSD, because I already had a RPi4 running 64-bit Lite from an attached SSD.

[ElRay70K70H]

Not too bad.  Looks like I have everything running, I'll just have to test it with a guitar & headphones.  I'm troubleshooting everything remotely right now.  The three services: jack, mod-host and mod-ui[ are running.  For completeness, I just needed to edit /etc/jackdrc to use hw:1 instead of hw:0

That said, I am still getting some errors from mod-ui:

Code: [Select]

Sep 26 15:08:13 pibox authbind[23072]: error: failed to expand CURIE `units:db'
Sep 26 15:08:14 pibox authbind[23072]: error: failed to open file /home/pistomp/data/.pedalboards//LICENSE/manifest.ttl (Not a directory)
Sep 26 15:08:14 pibox authbind[23072]: lilv_world_load_file(): error: Error loading file `file:///home/pistomp/data/.pedalboards//LICENSE/manifest.ttl'
Sep 26 15:08:14 pibox authbind[23072]: lilv_world_load_bundle(): error: Error reading file:///home/pistomp/data/.pedalboards//LICENSE/manifest.ttl
Sep 26 15:08:14 pibox authbind[23072]: error: failed to open file /home/pistomp/data/.pedalboards//.git/manifest.ttl (No such file or directory)
Sep 26 15:08:14 pibox authbind[23072]: lilv_world_load_file(): error: Error loading file `file:///home/pistomp/data/.pedalboards//.git/manifest.ttl'
Sep 26 15:08:14 pibox authbind[23072]: lilv_world_load_bundle(): error: Error reading file:///home/pistomp/data/.pedalboards//.git/manifest.ttl
Sep 26 15:08:14 pibox authbind[23072]: error: failed to open file /home/pistomp/data/.pedalboards//README.md/manifest.ttl (Not a directory)
Sep 26 15:08:14 pibox authbind[23072]: lilv_world_load_file(): error: Error loading file `file:///home/pistomp/data/.pedalboards//README.md/manifest.ttl'
Sep 26 15:08:14 pibox authbind[23072]: lilv_world_load_bundle(): error: Error reading file:///home/pistomp/data/.pedalboards//README.md/manifest.ttl

• For the first one, my GoogleFu might be weak, because I've only seen info on this in the Ardour forums, but I've got nothing GUI Front end related loaded
• For manifest.ttl errors, LICENSE and README.md are plain text files
• The manifest.ttl error inside .git I'm digging into. I'm seeing that error mentioned regarding LV2 plugins on the MODEP and Zynthian sites

[Randall (Admin)]

Don't worry about those errors.  The lilv library expects everything it finds in the pedalboard directory to be a pedalboard, but in reality there are other just plain files as you discovered.

Are you able to access the MOD Web UI though?  (by pointing a browser to pistomp.local/)

If so, at least the MOD stack is likely happy.  If it's processing audio and you can change things via the MOD Web UI, then you're probably all good.

[ElRay70K70H]

Everything is working fine, as best as I can tell.

Two odd things:

• Using a single guitar, with a mono cable, the audio in is now the "bottom" input. The default pedalboards all assume it's the top, and I'm 90% is was the "top" input jack when running MODEP/PatchBoxOS (1.10-ish MOD code)
• Also when running MODEP/PatchBoxOS, I had a CV/MIDI in jack at the very bottom.  Given the additions with 1.12 of the MOD code, I'm not surprised if this went away post 1.10

Thanks again.  I'll play with this for a while, and then likely start sourcing parts for my Crate Two-Tone conversion.

[Randall (Admin)]

I'm near certain those issues are caused by your interface/codec/alsa config, not MOD 1.12 or pi-Stomp.

The MOD UI doesn't have fixed I/O (audio or MIDI).  It presents the I/O that jack tells it about.  If your interface has MIDI and alsa/jack know about it, it should likely show in MOD UI.  You might try checking the alsa config file (/var/lib/alsa/asound.state) or the various alsa commands (amidi, aconnect, arecord, aplay, etc.)

[ElRay70K70H]

Yeah. I will have to troubleshoot this.  The CV connector appeared on all the pedalboards after a reboot this morning, but by the evening, it vanished again.

[Randall (Admin)]

Maybe you mean MIDI port?  I don't believe I've ever seen external connectors for CV.  Only CV connectors within a pedalboard that contains a CV plugin.  I'm not exactly sure what an external CV would mean.  Actual control voltage, not just symbolic voltage?  Not sure how an audio/midi card would support that.  Do you?

MIDI ports might disappear from the MOD UI when you don't have an active device plugged into the port.  I will gain MIDI ports when I have something plugged into a port.  If I turn off the device or unplug it, the port previously shown in the MOD-UI goes away.

I've also seen a MOD-UI bug where all ports (audio and midi) on one side of the browser disappear when the browser window is resized.  Generally a page refresh brings them back.