[LAU] [OT] Open Source Portable Recorder?

Johannes Kroll jkroll at lavabit.com
Mon Jan 7 17:42:26 UTC 2013

On Sun, 6 Jan 2013 08:48:35 -0800
"Len Ovens" <len at ovenwerks.net> wrote:

> On Sun, January 6, 2013 5:57 am, Johannes Kroll wrote:
> > Hi all!
> >
> > This is kind of off-topic here but I thought if there is such a thing,
> > some of you guys might know.
> >
> > I'm looking for an audio recorder where the firmware and/or the
> > hardware is hackable. Ideally, this would be similar to the Tascam
> > DR-05 in price and features, but with free/libre firmware and hardware.
> > Maybe someone knows of such a project?
> >
> > Alternatively, is any of the "closed" devices such as the Tascam DR-XX
> > known to have modifiable firmware?
> The price point would be the hard part. Any of the open hardware projects
> I have seen are more expensive than the closed projects, just because they
> are small and don't have the price cuts of large scale manufacture. The
> Open Moco is a great example in the smart phone world (one of the few that
> got to a usable/buyable product). And may actually work for you... though
> I don't know that it has stereo in.
> What I would suggest is to take something like the dr ($60 is cheap) for
> the case, mics and display and add one of the small open general purpose
> mother boards that are around. The gumstix or something similar would fit
> the case... there may even be an atom based board that would fit.... or
> would fit in a box not much bigger. The question would be how much time do
> you personally want to send hacking? (hardware hacking) How much can you
> spend? The computer swapout alone would more than double the price.
> As for hacking the unit itself, the first question is why. Not so much why
> you want to, but why would others want to. Before something gets the
> firm/software hacked there generally needs to be a reason at least a few
> people want to do so. Some extra functionality that is obvious (the smart
> phone has so much locked functionality it is frustrating so there are lots
> of hacks). The dr already seems to me to anything I would think of using
> it for,

As to why, I can think of a few things:

 - triggering recording at fixed time intervals, or based on some audio
   event like raised volume, or based on some external event, e. g. for
   syncing to a video camera
 - implementing USB audio so the device can be used as an external
   microphone. The recorders I've seen only output an analog signal.
 - changing recording parameters like custom sampling rates or different
   encodings. Commercial ones mostly do uncompressed WAV or MP3, but no
   lossless compression like FLAC for example.

Other people probably have other ideas...

Last not least, I simply like the idea of being in control of hardware
I buy.

As to price: the DSO nano is a free/open source oscilloscope which
isn't expensive at all, so building free and inexpensive hardware is
possible. Actually, using the DSO nano as a base could be a good
start for a recorder, it has A/D converters, mass storage and
everything... Just no mics.

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