Re: [Jack-Devel] Information request about audio Jack communication

On Wed, Mar 12, 2014 at 4:54 AM, David Brun <[hidden]> wrote:

> Hello,
>
> I am working on a project that involves the creation of a connected device
> (kind of captor) for smartphones / tablets.
> In order to get rid of connectivity limitations, I intended to use the
> jack audio port to connect the captor to the smart device, which is the
> only port present on every smartphone / tablet.
> I have seen a huge number of captors using this method, for instance:
>
>    - https://www.kinsahealth.com
>    - https://www.paypal.com/webapps/mpp/credit-card-reader
>    - https://squareup.com
>
>
Why do you think that JACK has anything to do with your project?


   - Would you have some pointers on documentation or other resources to
   help me find out how to implement this bi-directional communication between
   a smart device and a custom captor via a jack audio port?

This has not been done, unless you include the recent effort at an IIO
backend, but that is still streaming data, or the MIDI backend which can be
used to send arbitrary event data but is really totally disconnected from
what you are trying to do.

   - Would you know a software that could tell me what raw data transit on
   a jack audio port (even on a PC)? Monitoring a jack audio port with
   existing devices could help me analyze data and certainly understand much
   better how everything works.

JACK sends 32 bit floating point sample values, as a continuous stream.

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