Auto-detect USB speakers on boot

TuxArch · 02-25-2011, 07:52 PM

Hi,
I have logitech v.20 usb speakers that work great. Each time I boot however, I need to run "cat /proc/asound/cards" to identify my speakers, which produces the following output:

Code:

 0 [Intel          ]: HDA-Intel - HDA Intel
                      HDA Intel at 0xd5200000 irq 42
 1 [HDMI           ]: HDA-Intel - HDA ATI HDMI
                      HDA ATI HDMI at 0xd0030000 irq 43
 2 [Speaker        ]: USB-Audio - Logitech USB Speaker
                      Logitech Logitech USB Speaker at usb-0000:00:1d.0-2, full speed

Now that I see that the USB-Audio speakers are [2] (this changes each time I boot, sometimes it's 0 or 1), I manually edit /usr/share/alsa/alsa.conf and make these two lines point to the appropriate number

Code:

defaults.ctl.card 2
defaults.pcm.card 2

Is there any way to automate this process so that on boot the computer recognizes if the USB is plugged in or uses the internal speakers if not? And even better, is it is also possible to allow it to start out with internal speakers and automatically shift to usb if I plug them in after already having booted? Thank you very much!

corp769 · 02-25-2011, 08:17 PM

Hey man, I am working on something for you. Give me a little bit of time so I can get it right.

Cheers,

Josh

TuxArch · 02-25-2011, 09:41 PM

I think the following may be all that I need to add to /etc/asound.conf (that I created) ?

Code:

pcm.!default {
    type hw
    card Speaker
}
ctl.!default {
    type hw           
    card Speaker
}

corp769 · 02-25-2011, 09:53 PM

Did you try it?

TuxArch · 02-25-2011, 09:54 PM

I have implemented it, but how would I try besides restarting a bunch of time to see if it always matches the usb speakers? After one restart, the usb speakers defaulted but this could be due to chance?

corp769 · 02-25-2011, 10:13 PM

If you think it is due to a chance, then try to prove that it's not by restarting one more time and noting what number is being set.

corp769 · 02-26-2011, 06:26 AM

http://www.linuxquestions.org/questi...n-bash-865095/

Check this out.... I got drinking a few beers last night and decided to attempt at my (old) sed skills and come up with something. I ended up having to get some help, learned from it, and voila! enjoy.....

Cheers!

Josh