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Here's the video of the ZL3IN c2qso.sh contact. Remember, this is just raw UDP packets over the internet, with no error correction, and you're hearing the Codec2 audio just as it was transmitted in the conversation.

Over the weekend I had a half-hour conversation with Paul, ZL3IN, using Codec2. Paul corrected an error in the script I've published, and we were thus able to hear each other. His side of the conversation encoded in Codec2 is available here ; you can get my side here . I've also mixed the two into a wav file . Details and a video will follow.

If I haven't been using Skype for a while, I check that everything is working properly using their 'Call Testing Service'. This service tells you to record a message, then plays it back. Thinking that this would be great for testing a codec2-over-udp setup, I’ve been playing with a similar service, using this script: ncat –udp -l \$LOCAL_HOST \$LOCAL_PORT –sh-exec ‘netstat -nu | grep \$LOCAL_HOST:\$LOCAL_PORT | head -1 | cut -c 45-57 > /tmp/out.ip ; timelimit -t10 -T1 cat > /tmp/out.c2 ; cat /tmp/morig.c2 /tmp/out.c2 > /tmp/out2.c2 ; ncat –udp \`cat /tmp/out.ip\` \$LOCAL_PORT < /tmp/out2.c2'

Simon took me up on my offer in the last post, and after a bit of fiddling, I could hear his codec2-encoded voice reach across the Internet from Crowsnet Pass in Alberta to the Bay of Fundy. Great fun!

Over the holidays, I developed a bash script that allows to computers to communicate with codec2-encoded audio using UDP packets. The script, called c2qso.sh , doesn't do any of the firewall-punching magic that Skype etc. perform. But it should be useful in testing lightweight linux contexts, especially those without a GUI, since it comprises pipelines built from pretty standard Unix tools. Who'd like to arrange a QSO?

The TH-D72 USB port is configured as a CDC device, using the CP2102 USB UART bridge. On Windows, presumably you should use the drivers provided by Kenwood. I accessed the port on my Ubunutu 10.04 desktop just by using /dev/tty.USB0, which popped open when I connected the device. CP2102 support evidently is built into recent kernels. Looking around, it seems that MacOS support is more dicey, so I'll probably experiment with it using a linux box or a virtual linux machine on my MacBook. For the person like me, who is hoping to connect this to an embedded device, there's some particularly bad news: this chip doesn't communicate using the plain CDC-ACM; I'm told it has a proprietary communication system to the host. The best bet is to port the software from the linux kernel, alas. 

The new TH-D72 is a dandy radio, with APRS and a built-in GPS engine. But I was a bit dismayed to see that the CAT commands are somewhat different from those for the TH-D7G, since I'd put quite a bit of time into programming for those. Guessing that Kenwood wouldn't rewrite this software for each rig, I took a look at this list of commands for the most recent similar radio, the TM-D710, and sure enough, it seems they work. Phew. In addition, if we want a micro-controller to talk to this thing, then I suppose it will need to have USB host mode on it, since the rig acts as a USB device, of course. The CUI32 apparently provides the hardware for this connection, so we'll see how that works.