[LAU] Open Sound Interface project beginnings

alexander axeldenstore at gmail.com
Tue Oct 25 18:17:32 UTC 2011


On 10/20/2011 10:54 PM, Charles Henry wrote:
> Hi, list
>
> I'm interested in getting feedback for a project, namely building an
> audio interface, with the goal of creating freely available schematics
> and code required.  Hence, an Open Sound Interface.
>
> Once I've heard from all those interested, we may want to migrate the
> discussion to another development oriented list such as the
> linux-audio-dev list to work out nitty-gritty technical details.  For
> now, it's enough just to gauge interest and deal with planning issues.
>
> The concept is to create a modular and scalable system that allows
> users to create a sound interface with an arbitrary number of
> input/output channels.
> Goals of the system:
> 1.  low latency
> 2.  isolate design considerations
> 3.  abstraction of data transport types
> 4.  flexibility of adc/dac/preamp combinations
> 5.  no unnecessary features--keep it lean; niche features can be added
> in by those interested
>
> My idea for how to do it, and components/tasks to design:
>
> 1.  Modules for dac and adc with on-board identifiers  (mixed-signal design)
> 2.  A FPGA-based programmable system board with connectors for
> respective modules (high-frequency circuit design)
> 3.  FPGA code for buffers, clocks, and device discovery (VHDL/Verilog
> programming)
> 4.  Data transport modules (FPGA code plus hardware design), could be
> USB, FW, ETH, PCI, wireless, etc...
> 5.  Kernel modules for each type of transport (software design)
> 6.  Power supplies (not especially difficult, but tough to find
> off-the-shelf components to meet specs)
>
> What I'm doing:
> studying VHDL coding and preparing to test I2C/SPI dacs on a Digilent
> Basys-2 board with breadboards (maybe over a few months)
> studying high frequency electronics design
>
> This sort of problem would take a good team to do well.  There's room
> for many levels of software/hardware expertise, especially those who
> understand linux audio kernel modules (design for many parts of the
> system depend on capabilities to design for).
>
> It may be a chore, but some kind of organization and design documents
> will be needed.  All the components are inter-related: it takes a
> combination of top-down (whole system) and bottom-up (per module)
> considerations to build a complete design.
>
> Any feedback, insights, practical considerations, and reasonable
> expectations for taking a complex project like this to completion
> would be welcome.
>
> Thanks,
> Chuck
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> Linux-audio-user at lists.linuxaudio.org
> http://lists.linuxaudio.org/listinfo/linux-audio-user
>
Awesome, I've been thinking about this myself too, There actually is a 
DA interface project that I found some months ago.. maby one could use 
that as a base ! I might be able to contribute with some electronics, 
mostly testing.. I'm more or less a beginner atm but I know how all 
basic components affect the signal... But yes, this have to be done, 
It's not like there'll be better audio interface linux support in the 
future...


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