Re: Gnuradio Interface to a Tuning Knob?

[Marcus Müller]

Hi everybody,

I think there's two things here:

1. writing something that handles the input device (from joysticks to 
pedals to midi devices)
2. using the inputs to change something in your GNU Radio program.

I think 1. might actually be rather doable these days, when staying in 
Qt. (MIDI devices might actually be a bit tricky, but I bet there's a 
program that converts MIDI events to xinput device events.)
2. might be a bit more tricky: it's easy if everything you want to 
control just takes every control command using asynchronous messages 
(like the USRP blocks do, for example). Then, all you have to do is have 
some kind of way of defining what messages to emit when a specific input 
happens.
Sadly, not everything has message inputs for its functionality so far. 
PMT is really not helping the case, either, architecturally (kind of 
complicated to generate on the fly without writing code).

Best regards,
Marcus

On 05/08/2020 15.37, Derek Kozel wrote:
> Hi Kevin,
>
> Yes, I have one of these knobs, a Griffin PowerMate. There was support 
> for it in the WX GUI on Linux, so it's supported in 3.7 releases.
> https://github.com/gnuradio/gnuradio/blob/maint-3.7/gr-wxgui/python/wxgui/powermate.py 
>
>
> There was a longstanding kernel bug that ignored the 0 index step. A 
> fairly minor issue but I don't know if was fixed in newer kernels.
>
> I'd love to see someone use MIDI controllers in a GNU Radio based 
> application.
>
> Cheers,
> Derek
>
> On 8/5/2020 2:29 PM, Kevin McQuiggin wrote:
> > Hi All:
> >
> > I recall that at one time there was a gnuradio block that interfaced 
> > to some sort of physical tuning knob.  I am wondering if anyone 
> > remembers this and has some details?
> >
> > My recollection was that the device was from the gaming world, but 
> > that it was never that popular so support for it dropped several years 
> > ago.
> >
> > Thanks in advance,
> >
> > Kevin