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Question re soapy


James Dallas
 

Hello,

I rebuilt from source for 4.4.3 last night and now soapy seems to be working, both as source and sink.

Lime-on-Soapy seems a little more stable than "native" LimeSDR support, so I see the potential to use it especially for day-to-day SSB and NFM hamming.

However some of the options on the GUI don't make a lot of sense and some seem not to be working. Also I didn't see any tool tips indicating what stuff does.

Is Soapy support still work in progress? 

Specific areas of confusion/concern...

(1) What does Mod do? Doesn't seem to do anything for me.

(2) Next to the sample rate, bandwidth, bb freq there are list boxes with a value of 0. They don't seem to do anything.

(3) One minor annoyance... When I scroll down to fiddle with gain settings I frequently end up adjusting the LO offset instead. Could this be changed either to a direct input box (the same sort of UI element that sample rate uses) or perhaps add a lock button to the slider so that this can't be accidentally changed? I nearly lost my mind last night when it seemed like all the FM stations had disappeared (turns out I had just changed the LO offset that they didn't appear where I expected). Also I can't set the LO offset back to zero after changing it (closed is 0.4).

(4) The bandwidth setting doesn't actually seem to do anything but that may be a Lime/soapy issue. I think gqrx mayb do something similar.

(5) sometimes the gain sliders do weird things  (snap back to zero for TIA after  adjusting global) but I think this is a soapy issue. And may not even be an issue, in the sense that may be how it is supposed to work.

(6) There's a little bit of cutoff in the layout around DC correction.


Edouard Griffiths
 

Hi,

until LimeSuite 19.01 or 19.02 release becomes official it is still relying on 18.10.0 so make sure you compile LimeSuite from that tag and that the LimeSDR gateware is consistent. I haven't encountered such issues with the native LimeSDR support on both Lime-mini or Lime-USB. However I have tried to compile with the head of master of LimeSuite and had no issues even without changing the gateware.

(1) Anything that is inside the sliding area belongs to Soapy and "mod" control appears to do so I have no clue either. Whenever possible I have tried to derive tooltips from the information Soapy returns but this might not always be the case nor possible.
(2) The combo boxes next to sample rate, bandwidth, bb freq are there to support possible discontinuous ranges as supported by Soapy API. In the Lime case these are single ranges hence the range index values are reduced to only "0".
(3) I don't see the gain setting anywhere near the LO slider but maybe this is particular to the slidebar position. Maybe some separator can be added between the SDRangel settings and the Soapy settings area so that when scrolling controls do not get too close together
(4) As said in (1) and as you noticed this is Soapy business
(5) same as above
(6) strange... maybe I missed some height constraint when defining the widget. 

Brgds, Edouard.


James Dallas
 

Thank you for the heads up about the LimeSuite release. I'll go back and check my script re: tags... I don't think I'm actually checking that.

On Thu, Feb 7, 2019 at 11:38 AM Edouard Griffiths <f4exb06@...> wrote:
Hi,

until LimeSuite 19.01 or 19.02 release becomes official it is still relying on 18.10.0 so make sure you compile LimeSuite from that tag and that the LimeSDR gateware is consistent. I haven't encountered such issues with the native LimeSDR support on both Lime-mini or Lime-USB. However I have tried to compile with the head of master of LimeSuite and had no issues even without changing the gateware.

(1) Anything that is inside the sliding area belongs to Soapy and "mod" control appears to do so I have no clue either. Whenever possible I have tried to derive tooltips from the information Soapy returns but this might not always be the case nor possible.
(2) The combo boxes next to sample rate, bandwidth, bb freq are there to support possible discontinuous ranges as supported by Soapy API. In the Lime case these are single ranges hence the range index values are reduced to only "0".
(3) I don't see the gain setting anywhere near the LO slider but maybe this is particular to the slidebar position. Maybe some separator can be added between the SDRangel settings and the Soapy settings area so that when scrolling controls do not get too close together
(4) As said in (1) and as you noticed this is Soapy business
(5) same as above
(6) strange... maybe I missed some height constraint when defining the widget. 

Brgds, Edouard.


Edouard Griffiths
 
Edited

This is how the UI should look like. The DC correction (6) and mod (1) belong to the same block. This is a complex DC correction with modulus (Mod) and argument (Arg):

This will be corrected in next version.
Edit: the text values for mod and arg are wrong as well. Both should display 0.


Marty Wittrock
 

Edouard,

What is the purpose of the BB Freq? It seems to move the frequency around, but I would think that by clicking on the 'X' on the form you get the Delta Frequency and coarse adjust it to perform what 'NCO' used to do (shift the frequency down to HF from 30MHz based on what you enter). How would one center a frequency of, say, 7.125 MHz in the Main tuning control if the Delta Frequency has already been adjusted to -28 MHz? 

Thanks in advance for your help with this, Edouard - 73,

de Marty, KN0CK


James Dallas
 

Hi Marty,

Looking at the c++ class for soapy's user api, it looks like BB is intended to compensate for tuning errors.

It appears to stand for "Baseband" frequency.

I am not sure if this is really the same sort of offset that the "X button" offset tuning allows or not though.

On Fri, Feb 22, 2019 at 5:00 PM Marty Wittrock <martywittrock@...> wrote:
Edouard,

What is the purpose of the BB Freq? It seems to move the frequency around, but I would think that by clicking on the 'X' on the form you get the Delta Frequency and coarse adjust it to perform what 'NCO' used to do (shift the frequency down to HF from 30MHz based on what you enter). How would one center a frequency of, say, 7.125 MHz in the Main tuning control if the Delta Frequency has already been adjusted to -28 MHz? 

Thanks in advance for your help with this, Edouard - 73,

de Marty, KN0CK