Re: [Discuss-gnuradio] Extending UHD Device Support

[Tom Rondeau]

On Fri, Aug 26, 2011 at 11:45 AM, Wilson, Jeffery (DS-1)
<address@hidden> wrote:
> Designation: Non-SSA/Finmeccanica
>
> Matt,
>
> Thank you for your response. We will certainly be sure to abide by any and
> all licensing requirements as we move forward.
>
> As for now I would like to develop a simple source block (without using UHD)
> for our radio so I can at least do something like a basic FFT display as a
> proof of concept that we can in fact get our radio working in some way with
> GNU Radio. Is there anywhere I can find help/guidance specific to creating
> new source blocks other than picking apart the current ones? If not, which
> block(s) would be a good starting place?
>
> Thanks!
>
> -- Jeff

Hi Jeff,
Most of the hardware interfaces we have consist of a hardware
interface library (call it drs0) and a GNU Radio wrapper block around
that one that would be called gr-drs0. The gr-drs0 is structured in a
standard GNU Radio format. It inherits from a gr_block (actually, it's
usually a gr_sync_block), has a constructor to initialize the device
through the drs0 library, and has a work function that either gets
samples to push onto the flow graph for a receiver or takes samples
from a flow graph and sends them to the device for a transmitter. This
will also have wrapper accessors to get and set the properties of the
device, like frequency, gain, etc.

If you want to have a quick hack at it without the UHD, you can look
at how things were done with usrp and gr-usrp (or usrp2 and gr-usrp2),
which are both in the GNU Radio source tree.

If you can work with the UHD, though, I would recommend doing so. It
would make integration into GNU Radio projects much simpler.

Tom



> From: Matt Ettus [mailto:address@hidden
> Sent: Thursday, August 25, 2011 6:18 PM
> To: Wilson, Jeffery (DS-1); address@hidden
> Subject: Re: [Discuss-gnuradio] Extending UHD Device Support
>
>
>
> Jeffery,
>
> The first thing to keep in mind is that everything is GPL'ed (and
> specifically, *not* LGPL).  This means that if you use any UHD host code,
> you must obey the GPL for EVERYTHING that links in.  This goes all the way
> up to your customer's application.  This restriction already applies for GNU
> Radio itself since it is also GPL'ed.
>
> The firmware is GPL'ed.  This means that if you use any of the firmware,
> your ENTIRE firmware image must obey the terms of the GPL.
>
> The FPGA design is GPL'ed.  This means that if you use any of our Verilog,
> *everything* compiled into that FPGA image must comply with the GPL.  This
> would include all of your custom signal processing code, if it is in the
> same FPGA.
>
> The implementation of UHD host code is heavily oriented towards the state
> machines in the firmware and FPGA, so modifying it to work with other
> devices is easier if they use the same firmware and FPGA designs.  This is
> fine as long as you are ok with invoking the GPL requirements on those
> portions of your design.
>
> Users of Ettus Research hardware are able to use all of this under less
> restrictive terms in our alternative license.
>
> Matt Ettus
> President, Ettus Research LLC
>
> On Wed, Aug 24, 2011 at 8:23 AM, Wilson, Jeffery (DS-1)
> <address@hidden> wrote:
>
> Designation: Non-SSA/Finmeccanica
>
> Hello,
>
>
>
> We make several RF front-ends that we’d like to see supported in GNU Radio.
> Our initial idea is was to extend the Ettus UHD to include support for our
> devices, so that a waveform/flow graph using a UHD block could run using
> either a USRP or one of our devices with only minor modifications. Does it
> “make sense” to extend UHD for this purpose?
>
>
>
> Our radios are embedded Linux systems that can communicate over USB as well
> as Ethernet. Initially I would like to use Ethernet as communication (using
> sockets). As far as I can figure a good place to start would be to follow
> the USRP2 UHD implementation and re-implement it for our system.
>
>
>
> Any tips, examples or general guidance would be very much appreciated.
>
>
>
> Thank you!
>
>
>
> --
>
> Jeff Wilson
>
> DRS Signal Solutions, Inc.
>
> Direct: 301.944.8772