Using an OpenWrt router as a USB recorder

[bfields]

I got my Behringer X18 in part because I thought the 18x18 USB interface would be handy for live band recordings.  But in practice, time is always tight, and I rarely get around to setting up a laptop.

 

It occurred to me that I'm already hooking up a computer to my mixer every time, in the form of a wireless router--why couldn't it do this job?  It took a few days to figure out how, but I hacked something together, and it ran successfully and captured a few hours of audio at a show Saturday night.

 

Show night, the only steps required were to run a USB cable from the mixer to the router and plug in a USB drive.  As soon as the router detects both of those things, it starts recording automatically.

 

It produces data at about 3.5MB/second.  I don't think that's too fast for your average flash drive these days?  That comes out to about 12GB an hour.  I formatted the drive with ext4 because I was worried about hitting VFAT's 4GB filesize limit.  You could modify the script to break up output into smaller chunks instead.

 

But, it's probably very specific to my hardware.  You've got to reflash your router to OpenWrt, install some other software, then manually copy some scripts into place, and probably do some other configuration I've forgotten.  And although it worked fine Saturday night, it aborted after only 8 minutes at a Friday night rehearsal, and I haven't yet figured out why.  So, all in all, it's just a fragile hack for now.

 

Still, maybe it's useful to someone else.  And if it proves to be reliable, it should be doable to package this all up in a more convenient form:

 

  https://github.com/bfields/openwrt-recording

 

 

[stoken6]

Cool project. I love creative uses of existing gear.

 

Cheers, Mike.