[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Discuss-gnuradio] possible alsa error?

From: John Meloche
Subject: [Discuss-gnuradio] possible alsa error?
Date: Thu, 17 Jul 2014 10:41:08 -0400

sorry that the first message was sent before I could finish explaining.  my fault, please excuse.
I am using an 8 channel USB sound card as an audio source and the first test I do is to ensure that the audio signals can be seen in the attached QT scope block screen shot. This works perfectly when the PC is first started, however when I stop the flow graph and then start it again I get an alsa error message.
When the flow graph is working correctly I get the following message:
<<< Welcome to GNU Radio Companion 3.7.5git-0-g2bb2b314 >>>
Preferences file: /home/drdc/.grc
Block paths:
Loading: "/home/drdc/Documents/8 ip switch test.grc"
Showing: "/home/drdc/Documents/8 ip switch test.grc"
Generating: "/home/drdc/Documents/InputSwitchTest.py"
Executing: "/home/drdc/Documents/InputSwitchTest.py"
Using Volk machine: avx_32_mmx
After the flowgraph is restarted I get the error message that can be seen in the attached screen shot.  running sudo alsa force-reload does not fix the problem.  Only a reboot will fix it.
Some background:
To get the USB sound card to work at all I have done the following:
1 removed pulseaudio
2 blacklisted the internal sound card
3 running aplay -l lists only the USB sound card (exactly what I need)
The audio source block device ID must be left blank to work
If I specify hw:0,0 or plughw:0,0 I get errors telling me that I am not using enough ports or am using too many ports.  I think that it is looking at the SPDIF and MIDI ports on the USB sound card that I do not use.
As always any advise is appreciated.

Attachment: QT GUI Plot.png
Description: PNG image

Attachment: Flowgraph with error message.png
Description: PNG image

reply via email to

[Prev in Thread] Current Thread [Next in Thread]