Sound problems, TP-link 703N

Discussion about my Wifi Radio project at http://mightyohm.com/wifiradio/ or my WL-520gU talk at NOTACON.
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Dac
Posts: 7
Joined: Sat Jan 05, 2013 5:34 am

Sound problems, TP-link 703N

Post by Dac »

Hello all, and thank you for sharing this awesome project! I have successfully transformed 3 devices into wi-fi radio so far:

First it was Siemens SX763, which is actually DSL modem/router given to users by biggest local ISP. So it's cheap, easy to find and on paper quite powerful. Still buggy, but supported by OpenWRT and in development: http://wiki.openwrt.org/toh/gigaset/sx76x
Second, Ubiquiti RouterStation Pro, too expensive device for this, but it was just sitting there while I was waiting for some bugs to be ironed out on WRT for Siemens.
Third, TP-Link TL-WR703N, which seems like an ultimate device for this http://wiki.openwrt.org/toh/tp-link/tl-wr703n , except for flash memory being too small for mpd package. This is solved with USB hub, small USB flash memory (old and unused 256 MB in my case) and extroot.

I have used several versions of WRT, Backfire, Attitude Adjustment beta and RC1, and some daily snapshots.
Sound cards used are el cheapo GigaTech (lsusb reports " C-Media Electronics, Inc. Audio Adapter (Planet UP-100, Genius G-Talk)") and SteelSeries Siberia USB, also C-media based (lsusb says "C-Media Electronics, Inc. Audio Adapter"), should be different chip used with virtual 7.1 surround options and other gaming stuff.

So, the problem: it all works fine as long as wifi is turned off. Didn't get there with RouterStation (only used on LAN), but both Siemens and TP-Link produce same chopped, garbled sound as soon as wifi works. Wireless mode doesn't matter, or if it's in fact used for connection. Wireless on, sound goes bad and only one thing can be done - turn wifi off, reboot, and sound is good again.

Anyone experienced that problem? Any advice?
Last edited by Dac on Sat Jun 29, 2013 3:19 am, edited 1 time in total.
TP-Link TL-WR703N running Attitude Adjustment 12.09

Dac
Posts: 7
Joined: Sat Jan 05, 2013 5:34 am

Re: Sound problems

Post by Dac »

Unfortunately, in the Atheros AR9331 chip which is the heart of the TL-WR703N router, it looks like there is only an EHCI device and no OHCI. For some unknown reasons, full-speed devices seem to work somehow, but very unreliably, like what you observed with the Arduino communication. It looks like that this phenomenon is linked to the WiFi operation, as if you turn it off, you don't have problems.
https://forum.openwrt.org/viewtopic.php ... 41#p187441


Oh well... :roll:
TP-Link TL-WR703N running Attitude Adjustment 12.09

Dac
Posts: 7
Joined: Sat Jan 05, 2013 5:34 am

Re: Sound problems

Post by Dac »

Good news! It seems that some bugs have been squashed when OpenWRT came out of beta, so on final 12.09 wireless and USB sound work together without chopping. :D

Not that this setup is without problems (for us noobs) because Atheros and WRT don't play nice in client mode, I was hoping that was fixed also but isn't. Wireless is active, connected, got the address from DHCP, but can't access it directly. I can open Luci or get ping to address obtained from DHCP only when ethernet (with fixed IP) is connected.

edit: yes, relayd did the trick :)

http://wiki.openwrt.org/doc/recipes/relayclient
https://forum.openwrt.org/viewtopic.php ... 67#p173467
http://cavebeat.blogspot.co.at/2012/08/ ... ridge.html
TP-Link TL-WR703N running Attitude Adjustment 12.09

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