Re: [Discuss-gnuradio] Writing a Radio Driver

[Marcus Müller]

Hi Harrison,

There's no "driver architecture" in GNU Radio; you just write
sink/source blocks.
If you have a few minutes to spare, start with the GNU Radio tutorials
[1] from start to hardware; that should give you a solid primer on how
things work with GNU Radio. If you then know how you get your samples
from the ADC through your Zynq into your userland, you're basically set
:D well, aside from minor things like figuring out how to expose your
hardware controls most practically to GNU Radio, and how to avoid overhead.
Again, there's no standard for hardware control in GNU Radio[1].

UHD is quite specific to Ettus devices, so I don't think screwing your
stuff onto that seems very wise (though I've seen parts similar to yours
in Ettus products ;) [2]). UHD, though, is open source, including the
FPGA image and the matching drivers as well as the userland interface,
and I don't think the developers mind you looking at the code they
produced to tackle the FPGA-userland interface.

Greetings,
Marcus


[1] maybe there should be. I think we should wrap this up in clean
interface specifications, and define CORBA objects for that :D j/k.
[2] There is an upcoming embedded USRP, employing a Zynq, the E300.
Ettus presented some information on grcon 2014:
http://www.trondeau.com/storage/grcon14/presentations/Sep16_05_Ettus_Updates.pdf

On 16.10.2014 20:21, Harrison Caudill wrote:
> Hello Everyone,
>
> I have a custom PCB to power an SDR, and I'm going to need to provide
> a gnuradio driver for it.
>
> We are using:
>  * Xilinx Zynq 7020 SoC
>  * Analog Devices AD9364 ADC
>  * AvNet ZedBoard for prototyping
>
> I can only imagine that we will ultimately use a tweaked version of
> the Ettus Research UHD driver.  I have found a couple of other drivers
> that people have written, as well.
>
> Short of old-fashioned source-diving, I am unsure of where to begin.
> Can anyone recommend some good reading on the gnuradio architecture
> and/or driver layer?  I'm guessing I'll have to write a source block
> for the radio, leaving the issue of running the flow graph on the PL
> of the Zynq and interfacing properly with the AXI bus.
>
> Thanks,
> Harrison
>