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Thread: Teensy 4.0 : Adat input ?!

  1. #1

    Teensy 4.0 : Adat input ?!

    Hi,

    I'm a newbie with teensy and I'm looking for create a DSP module with Faust Langage (I used a lot !). I saw that Adat Output works great with teensy 3.X but Adat Input wasn't available because of the hardware. Teensy 4.0 has optical output (and Adat will work great) but it also has optical input now :-). Do you think Adat input will work ?? I already imagine a multi-voice spatializer !!...

    Thanks !!

    Pierre-Adrien

  2. #2
    Member
    Join Date
    Aug 2016
    Location
    Australia
    Posts
    95
    Hi,

    I have ADAT gear and took a look at this a while ago. Output of ADAT turns out to be far simpler than input.

    Output starts be NRZI coding the data stream, which is a well documented algorithm, and then bit transmission is driven by a timer interrupt. The Audio Library ADAT object code shows how this is done.

    Input requires synchronization with an clock embedded in the bitstream and then decoding by a different algorithm. Because of the sync requirement, solutions tend to need a significant hardware component. There are some around with FPGAs (e.g. https://ackspace.nl/wiki/ADAT_project or https://opencores.org/projects/adat_...rward_receiver), and others using the venerable Wavefront AL1401/1402 chips which are becoming increasingly rare.

    It is possible that the Teensy 4 processor moves this forward, as there is an improved clock synchronization and an inbuilt PLL, but I'm not familiar enough with the new hardware to know whether this approach is practical.

    I hope this helps.
    Last edited by palmerr; 02-06-2020 at 09:41 AM. Reason: typos

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