JAAA Spectrum Analyser and the RPi - can't get it working - Page 1
Forum section: electronics / projects

author: rjmusto
author_rank: Contributor
timestamp: November 19, 2021, 10:10:08 am
content: HI all,In the past I have made good use of the JAAA audio spectrum analyser running on a RPi. Neat and handy piece of software.Recently thiough I have tried to get it working on a RPi 4 but all efforts have failed. The app runs ok, but no trace shows up - so not connecting to any inputs.This is no doubt something to do with how the Pi is handling the audio - have tried removing Pulseaudio, which can get in the way, but so far nothing I've tried has got it working.Anybody on here had success with this? Any tips on what is needed?Thanks,Ralph

author: mag_therm
author_rank: Frequent Contributor
timestamp: November 19, 2021, 03:00:19 pm
content: I was also unable to get jaaa to work stand -alone. (Fedora 32)Do you have jackctl installed?Firstly I open amixer or alsamixer to set the audio capture at 0dB at hw level.Then start jackctl with >setup connecting to the sound card I want.In > setup > options there are cmds you can add to momentarily kill pulseaudio, then restart it.I can give you those if needed.That allows pulseaudio to work with jack, but I am not understanding fully how.Then open the graphic (GUI) patchpanel ( it is miss-called "Graph" lower left button). A lot easier to use than the >PatchBayThen invoke jaaa. It will immediately show on the GUI.You can pull the green cables to connect to its In_1 and In_2 The jaaa outputs do not work here.The jaaa should start to display.Re-Set the analog alignment level in alsamixer to match jaaa dBfs level according to your noise floor.I set it about -20dBfs for 0dBu 0.775 Vrms but there are various other standards.Set jaaa low dBfs , 16 bit noise floor is about -80 to -90 dB approx .Setting freq on jaaa seems to need the full string like this: 3.0k for 3000 Hz range ( need to enter the decimal point and kYou can also start calf now, and patch in its filters etcHope this helps.

author: rjmusto
author_rank: Contributor
timestamp: November 19, 2021, 04:24:57 pm
content: Hi,Thanks for the detailed reply.I haven't used Jack previously, so on a bit of a learning curve here...I have it installed and got as far as your"You can pull the green cables to connect to its In_1 and In_2 The jaaa outputs do not work here."part, but am at a bit of a loss what the green cables are here. Have I missed a step in the process perhaps?The screenshot shows what I am looking at.Many tahnks.

author: mag_therm
author_rank: Frequent Contributor
timestamp: November 19, 2021, 05:00:40 pm
content: From your png, I can see that you do not have a capture enabled.>SetupIn settings, > "Interface" will drop down to show the available ones.Use alsamixer or amixer to help if you have a lot of them.I use Driver: alsa Rate 48000 frames 1024 periods 2>Options # add the cmds"Check Exe script on startup" : pulseaudio -k"Check Exe script after startup": pacmd load-module module-jack-source channels=2; pacmd load-module module-jack-sink channels=2;Everything else at defaultsNow save that setup in settings "My_pch_capture", you can make one file for each capture sound card#It was difficult for me to realize that the whole jackctl seems to be able to only run on the one capture interface.#It is not able to handle more than one stereo channeI have not tried 2 instances of jackctl yet."My_pch_capture" is exe when you select it and >apply >OKWhen that is successful, the capture interface will appear on left side of the GUI, so you can pull cables from it to jaaa.To pull a cable.left click on a green output terminal -it will turn blue.Hold left click then pull the blue cable, it will snake after your mouse as you pull it to the input terminal.If all is good, the blue cable will turn green.As I mention jaaa outputs do not work, so pull more cables from input to system playback

author: HB9EVI
author_rank: Frequent Contributor
timestamp: November 19, 2021, 05:15:04 pm
content: you don't need jack to run jaaa or japa; just start them with the -A flag and it uses the regular alsa devices.if you're not going to run your own home studio, it's not worth the pain run jack; it's a rather complexe piece of software in every days life not really necessary; I run jack only on my home studio workstation, everywhere else I just use alsa/pulseaudio

author: rjmusto
author_rank: Contributor
timestamp: November 19, 2021, 05:34:40 pm
content: Ok, was being a bit of a numpty.....I didn't have the USB audio dongle plugged in, so the correct interface never showed up.Now it's working. Happy days.HB9EVI :-I never got it to work with -A. No idea why, but ah well, I've learnt a bit about Jack......73Ralph

author: mag_therm
author_rank: Frequent Contributor
timestamp: November 19, 2021, 05:48:10 pm
content: One of Jack's problem is the lack of documentation.I am feeding ft8 mode to wsjt-x. I wanted to go through some af filters for ssb too so calf is useful. jaaa is a better s.a. than the one in calfIt took me a long time to figure out alsa and jack . I have written some down but still don't have a good understanding of it.Here is Fedora 32:[PR_mag_therm@localhost ~]$ man jaaaNo manual entry for jaaa[PR_mag_therm@localhost ~]$ man jackNo manual entry for jack[PR_mag_therm@localhost ~]$ jaaa --helpJaaa-0.8.4(C) 2004-2010 Fons Adriaensen <fons@kokkinizita.net>Options:-h Display this text-name <name> Jack and X11 name-J Use JACK, with options:-s <server> Select Jack server-A Use ALSA, with options:-d <device> Alsa device [hw:0]-C <device> Capture device-P <device> Playback device-r <rate> Sample frequency -p <period> Period size -n <nfrags> Number of fragments Either -J or -A is required.[PR_mag_therm@localhost ~]$ jaaa -A -d hw:1Can't connect to ALSA[PR_mag_therm@localhost ~]$