Re: [Discuss-gnuradio] A Question on WX GUI FFT Sink

[Tom Rondeau]

On Mon, Oct 1, 2012 at 4:35 PM, LD Zhang <address@hidden> wrote:
> Well I should have been more patient before I sent out the last email. It
> turns out for the functionality I want (flexible zoom in display of the fft
> spectrum) the block is called simply "QT GUI sink", if I am not mistaken.
>
> When I tried, there is the error message:
>
> -------------------------------------------------------
> Traceback (most recent call last):
>   File "/home/ldz/usrp_tests/top_block.py", line 75, in <module>
>     tb = top_block()
>   File "/home/ldz/usrp_tests/top_block.py", line 58, in __init__
>     self.top_layout.addWidget(self._qtgui_sink_x_0_win)
>   File "/usr/local/lib/python2.7/dist-packages/gnuradio/gr/top_block.py",
> line 94, in __getattr__
>     return getattr(self._tb, name)
> AttributeError: 'gr_top_block_sptr' object has no attribute 'top_layout'
> -----------------------------------------------------------------------------------------------------
>
> I took a look in the top_block.py in my test directory. But I don't
> understand the problem. I have not yet become accustomed to the python
> environment.
>
> Please off suggestions. Thanks.
>
> LD

In the Options blocks, you have to change from using WXGUI to QTGUI.

And just use the QT Sink block. From there, you can switch between the
FFT, spectrogram, time, and constellation modes.

Tom


> On Fri, Sep 28, 2012 at 3:39 PM, Josh Blum <address@hidden> wrote:
>>
>>
>>
>> On 09/28/2012 02:15 PM, LD Zhang wrote:
>> > Hello,
>> >
>> > I have a simple GRC demo where the USRP source goes to a WX GUI FFT sink
>> > and WX GUI Scope sink. They appear to be a good tools for sanity checks.
>> > One feature I don't find however but I think should be quite necessary
>> > is
>> > when one needs to examine a portion of the FFT spectrum more closely.
>> > But I
>> > don't find an option where one can specify the start and stop frequency
>> > for
>> > the FFT spectrum display. Am I missing something?
>> >
>>
>> WX FFT sink cant do this. But...
>>
>> FWIW, the QT gui FFT display sink does have a zoom feature.
>>
>> -josh
>>
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>
>
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