USB sound card compatibility

Forum for discussion about the Langstone Microwave Transceiver that shares some features with the Portsdown. Wiki: https://wiki.microwavers.org.uk/Langstone_Project
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g4eml
Posts: 752
Joined: Thu Apr 26, 2018 9:36 am

USB sound card compatibility

Post by g4eml » Fri Jun 05, 2020 3:13 pm

As USB sound cards from different manufacturers have different names it is currently necessary to edit the files Lang_TX.py and Lang_RX.py to reflect the card name.

I think it might be possible to identify the card by number rather than name which might remove the need to edit the files.

If you currently have to edit the file to work with your USB sound dongle could you please give this a try.

Change the name definition from "hw:CARD=Device,DEV=0" to "hw:CARD=1,DEV=0"

This seems to work for my USB dongle. If it works for others then I will make this the default setting.

CARD=0 seems to always be the built in raspberry pi audio socket, I am assuming the first additional USB device will always be CARD=1.

You can enter cat /proc/asound/cards to list the card numbers and names.

Colin G4EML

w0iy
Posts: 27
Joined: Sat Jul 04, 2020 2:38 am

Re: USB sound card compatibility

Post by w0iy » Wed Aug 05, 2020 2:51 am

cat /proc/asound/cards
0 [Headphones ]: bcm2835_headphonbcm2835 Headphones - bcm2835 Headphones
bcm2835 Headphones
1 [H540 ]: USB-Audio - Logitech USB Headset H540
Logitech Inc Logitech USB Headset H540 at usb-0000:01:00.0 -1.3, full speed


I tried hw:CARD=1, DEV=0 with no luck.

w0iy
Posts: 27
Joined: Sat Jul 04, 2020 2:38 am

Re: USB sound card compatibility

Post by w0iy » Wed Aug 05, 2020 3:47 am

a link of possible interest: https://wiki.gnuradio.org/index.php/Audio_Sink#Linux

I do believe there is an error in the last line under Linux. In regard to ", if there are no "xxxx" (quotes around the arguments) then there is a syntax error at run time.

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M5TXJ
Posts: 347
Joined: Wed Jul 05, 2017 8:34 pm

Re: USB sound card compatibility

Post by M5TXJ » Fri Sep 04, 2020 8:39 pm

Hi folks,
I'm slowly gathering parts to build a Portsdown 4 Langstone combo, I have a stock of CM108 USB sound dongles, can these be used?
73 Dave
...are you sure I can't use a pair of 813's?... :shock:

g0mjw
Posts: 2568
Joined: Sat Sep 20, 2014 9:15 am

Re: USB sound card compatibility

Post by g0mjw » Sat Sep 05, 2020 7:45 am

Almost anything can be used if you are prepared to modify the code to enable it. That's not too difficult if you are a familiar with programming. You just need to work out what the device is identified as and that it can produce audio at the correct sample rate. When I was waiting for my proper dongle to arrive I managed to get my Sennheiser headset to work relatively easily by modifying the Python script. viewtopic.php?f=129&t=6602&p=22472&hilit=headset#p22472

However, you need to know what you are doing. To check your dongle, use the aplay -L command and see what it gives.

Otherwise, I would advise sticking to the recommended dongles, they are not expensive., they work, it's much kinder to the developers. The CM108 looks very similar to the one Colin recommended, so you may be lucky.

Mike

g4eml
Posts: 752
Joined: Thu Apr 26, 2018 9:36 am

Re: USB sound card compatibility

Post by g4eml » Sat Sep 05, 2020 8:36 am

Many of the low cost dongles use the CM108 chip, so it is likely that it will work.

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