Author Topic: pi-stomp 1.0.2: no output via processing chain; capture problem?  (Read 1364 times)

collinsr

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pi-stomp 1.0.2: no output via processing chain; capture problem?
« on: November 21, 2021, 12:09:49 AM »
My pi-stomp 1.0.2 is up and running, but I can't seem to get any output via the processing chain; it looks like I've borked the input / capture somehow?

Here's what I've tried:

1) Guitar to amp works fine in bypass mode

2) Tone generator to amp (and headphones) works fine in processing mode; volume knob works as expected

3) Guitar to pedalboard has no signal-- I connected input 1 to the TinyGain monitor, and it never budges

4) (3) holds true for inputs 1 and 2, and various settings of the input gain via the system menu

5) I ran the amixer set -c 0 'Output Mixer HiFi' on command from the troubleshooting section; no effect

...FWIW, jackd is running with the following parameters:

/usr/bin/jackd -t 2000 -R -P 95 -d alsa -d hw:audioinjectorpi -r 96000 -p 64 -n 2 -X seq -s -S

...let me know if there are any other tests or diagnostics I can run...

Thanks!

Randall (Admin)

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Re: pi-stomp 1.0.2: no output via processing chain; capture problem?
« Reply #1 on: November 21, 2021, 11:25:59 PM »
Your jack config is likely too CPU intensive for anything except a very small pedalboard.  I would recommend trying these:
-r 48000 -p 128

But that's still probably not the root cause.  I agree it sounds like the input never makes it to the the sound card, or if it does, it's not making it to MOD.

I just made a quick fix to allow the host test mode (added for v2 by BenH) to also work (mostly) for v1 hardware.  You can use it to see if your audioinjector is receiving any audio.

Here's what to do...

First make sure your input gain is high-ish.

Then, via a network connected SSH session:
cd ~/pi-stomp
git pull

sudo systemctl stop mod-ala-pi-stomp jack

(That might take a while)

ps-run --host test

That'll bring up a curses UI.  With your instrument cranked, play it and look for VU meter type action next to the L or R Capture fields.

If you see segments "lighting up", then the audio card is receiving output and we'll try to figure out why MOD doesn't appear to be receiving it.  If no segments, then I'm suspecting a hardware problem.  Let me know, and we'll go from there.   











benh

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Re: pi-stomp 1.0.2: no output via processing chain; capture problem?
« Reply #2 on: November 22, 2021, 04:21:36 PM »
You might have to stop jack as well to get audio in test mode

Randall (Admin)

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Re: pi-stomp 1.0.2: no output via processing chain; capture problem?
« Reply #3 on: November 22, 2021, 04:29:49 PM »
yes, jack is included on the systemctl stop line.

What I forgot though, is once you're done using that test mode, Control-C to exit, then you'll either need to reboot or run this to get back to normal:

sudo systemctl restart jack modep-mod-host modep-mod-ui mod-ala-pi-stomp

benh

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Re: pi-stomp 1.0.2: no output via processing chain; capture problem?
« Reply #4 on: November 23, 2021, 08:18:21 PM »
Ah oops, ****t in my eyes :-)

collinsr

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Re: pi-stomp 1.0.2: no output via processing chain; capture problem?
« Reply #5 on: December 03, 2021, 11:07:02 PM »
The ps-run --host test shows nothing on either of the captures when plugged into to either input. I pulled out my scope and the signal is on the audioinjector's right input pin for input 1.

I plugged in my headphones and tried the beep command on ps-test; I can hear the beep and it responds to the volume controls.

With the full pi-stomp software going, a pedalboard with a metronome sends output to my amp (woohoo!) (edit: I see I had the tone generator working in my original post...) ... it sounds like maybe the audioinjector's ADC is borked?

« Last Edit: December 03, 2021, 11:09:25 PM by collinsr »

Randall (Admin)

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Re: pi-stomp 1.0.2: no output via processing chain; capture problem?
« Reply #6 on: December 04, 2021, 07:43:22 PM »
Yes, sounds like something on the input side of things.  Are you saying that your scope does show signal making it to the AudioInjector's input pad?  That would suggest that at least it's not the buffer or relay.  Then it would either be the AI card failing, or some software configuration preventing it from working.  Just to make certain, I'd construct a pedalboard like below with both inputs routing to both outputs and tinygain meters on each. 

And make sure the output of this:
amixer get -c 0 'Output Mixer HiFi'

returns:
Mono: Playback [on]

And:
amixer -c 0 get Capture

returns a percentage above 70%

If not, run:
amixer -c 0 set Capture 90%


If none of that works, then yeah, I suspect something wrong with the audioinjector.  If we decide that's it, I'll send you a new one.