Unique USB identifier

A project log for 4chord MIDI

4chord MIDI - the USB MIDI keyboard to play every major hit pop song with four little buttons.

sven-gregoriSven Gregori 08/03/2017 at 18:323 Comments

Thanks to the folks at, 4chord MIDI has now its own unique USB vendor/product ID pair! In practice this means that one could add a udev rule specific to 4chord MIDI, and for example automatically execute a shell script whenever a device gets plugged in, which could then start fluidsynth and automatically connect it via aconnect. Or start jackd and a2jmidid to get Ardour ready for MIDI recording.

Well, I guess those two example udev rules just made it on my TODO list..


oshpark wrote 08/24/2017 at 04:40 point

Thanks for sharing this!  USB VID/PID is a gotcha for many Open Source Hardware projects, so it is great that you've explained how to get one.

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Sven Gregori wrote 08/24/2017 at 07:19 point

Some more background on it is in the Hackaday article I heard about in the first place:

If one is familiar with git workflow, it's really straightforward if you follow their instructions. They are quite strict on the licensing part - if you don't put an open source license file into your project directory, you won't get lucky, which I think is a good thing (despite me learning that the hard way).

Also worth noting is that this is some volunteer side project and not operated like a business, so pull requests might take some time (weeks even) until they get handled.

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Sven Gregori wrote 08/20/2017 at 00:51 point

Wasn't even kidding, at least the fluidsynth udev rule example is now in the Github repository, including a little installation script:

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