Re: Yaesu Digital support / Codec2 support

"John D. Hays" <john@...>


NW Digital Radio doesn't have any current project plans to implement either Fusion or Codec-2 on the UDRX-440.

That being said, here are some thoughts for someone who would like to support them.

Yaesu has prepared a document which describes the protocol in detail here. The DV3000 card we have developed should be able to encode and decode the Fusion AMBE stream, both half rate and full rate, and one would need to implement the protocol stack.  Also a C4FM modem would need to be written for the UDRX (preferably in fixed point math).  We would be willing to give integration guidance to a developer wishing to implement the modem using our I/Q interface so that it has a socket interface like our GMSK, MSK, and other modems. (This would allow re-use for other protocol stacks, for example the D-STAR spec is not limited to GMSK or it might be used for Codec-2.)

A DV3000 card and Raspberry Pi would allow someone to start work on the protocol stack ahead of the creation of the modem and release of the UDRX.  

We have been following Codec-2 development and there are a couple of ways to implement it.  Currently, Codec-2 has not defined a VHF/UHF repeater and networking protocol or modulation, the work has been primarily focused on HF to this point.  The digital stream for the vocoder and protocol stack could be run in 3 different ways:
  1. Using an external computer and sending/receiving through the UDRX via a network socket.
  2. Implement it directly on the UDRX.  We are not confident that this will be possible without rewriting the vocoder in fixed point as the UDRX does not have a floating point processor.  It may be possible as some work has been done in Belgium using the Raspberry Pi, but we beleive it has been built using the hardware FP, rather than the software implementation.
  3. Do what DVSI does with the AMBE vocoder and put in on a specialized DSP processor and mate it with the UDRX interface for the DV3000 card. . 
So it should be possible to support these modes on the UDRX, if someone wishes to pursue development.

John D. Hays
PO Box 1223, Edmonds, WA 98020-1223 

On Sat, Apr 19, 2014 at 6:33 PM, Vaughn Phillips <vaughn.w0ulf@...> wrote:

Hello all,

Silly question: is anyone out there aware of whether there will be any available Codec2 or Yaesu digital support (From the team or from the community at large) for these formats on the UDRX-440?

I tried searching the group for anything about these and only ran across some side conversations about these protocols: nothing directly related to whether they'll be "available" for this platform. Please don't shoot me if I missed this somewhere else - but a link to it would be greatly appreciated if I did.

I know we've got a little while before the hardware ships out, so I suppose there's still a chance for this to happen if someone hasn't already made it reality. And no, I'm not volunteering to learn to program well enough to get this done any time soon :P


-Vaughn Phillips
Albany, Oregon, USA


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