Tag Archives: opera

Location based sound, part two

Our first public test for the The swamp that was, a bicycle opera takes place next weekend, so I’ve been working on the on-bike software and getting more experience with the BeagleBoard while Kaffe builds up the sound pieces. In order to test the software, I’ve made a local map I can play with:

Each coloured zone represents a different audio sample. We are also experimenting with direction, panning each sound depending on your direction and that of the sound source. For example it’s possible to set a sound to come from the north, which pans it to the left if you are heading in an easterly direction and the reverse. Using this test map, I can run the system on battery while out walking the dog:

The Swamp that was, a bicycle opera

Day one on a new project – with Kaffe Matthews, and a collaboration between FoAM & Timelab, “The Swamp that was” is an opera where bicycles become a way to hear stories of the past in the city of Ghent.

I’m picking up the software side of things from Wolfgang Hauptfleisch, which involves using BeagleBoards – low power self contained open hardware ARM computers, a good follow up to my experiments with the considerably more closed NDS and less general purpose Android.


This is my test BeagleBoard xM in a custom laser cut housing from Timelab.

The “swamp” system is based on lua scripts calling proteaAudio for realtime audio processing. Lua has a tiny footprint and is great as an embedded interpreter (despite indexing from 1 and other minor gripes). Everything seems to be up and running, and I’ve set up a project on gitorious with the sourcecode.

Some random things I’ve learned include: flags to speed up dd copying images to extremely slow usb SD memory cards:

sudo dd if=swamp0-1.img of=/dev/sde oflag=dsync bs=1M count=1024

List ip addresses of devices attached to your local router:

sudo arp-scan --interface=wlan0 192.168.1.0/24

I’m using the Ångström distribution on the beagle board, which uses opkg for package management – it took me a long time to figure out the best way to search for packages is simply:

opkg list | grep alsa