Re: [Discuss-gnuradio] UHD examples/apps

[Josh Blum]

> Hmmm, this will require some thinkage.  I just ran into a *similar* 
> problem when running Tom's uhd_fft.py on a BASIC_RX, because it sets
> the antenna, and of course, there aren't any antenna options on the
> BASIC_RX.
> 

I would like the app to only set the antenna when the option is
specified. So if options.antenna: self.u.set_rx_antenna(....)

> The question becomes whether we place the burden on the user app to 
> "know" what is reasonable, and not ask UHD to set things that aren't
> actually there, or whether there should be some kind of *explicit*
> "default" value that means "don't barf on me, bro".
> 

The UHD should handle all cases and throw a reasonable error like "no
antennas to select". Those neglected properties should be filled in for
the sake of completeness.

Whether or not to use an empty string as a pass-through, not so sure.

> For a hand-coded Python/C++ app, perhaps it's reasonable for the APP
> to ask UHD what features are available, and only ask for settings
> related to those features.  But for GRC, it's harder to do that sort
> of thing, since GRC is inherently declarative, and not procedural.
> 
> 

Indeed.

The available antennas are query-able. Available clock configurations
are not yet. Thats planned for the next rev of the API.

-Josh