Re: [Discuss-gnuradio] Doppler shift on waterfall plot with audio signal

[Chris Kuethe]

No reason. Just scribbled up a quick flowgraph to demonstrate the use
of a computer's microphone and speakers to do audio frequency DSP with
gnuradio.

On Fri, Oct 21, 2016 at 1:56 PM, Garver, Paul W <address@hidden> wrote:
> I'm not familiar with your application. But you would get better frequency 
> resolution for the same length FFT if you decimate after the BPF. It would 
> probably be easier to see what is going on. Is there a reason you are 
> significantly oversampled?
>
> Paul Garver
>
>
>> On Oct 21, 2016, at 3:31 PM, Chris Kuethe <address@hidden> wrote:
>>
>> I've been meaning to do some more experimentation here using CW, FMCW,
>> and chirps.
>>
>> You should be seeing a bright line down the middle of the waterfall.
>> If not, your hardware isn't working - I'm thinking it's your speakers
>> since you do seem to be gettting *something* from the microphone on
>> your FFT. You won't hear the tones since they're ultrasonic, but is
>> your sound muted?
>>
>>> On Fri, Oct 21, 2016 at 10:01 AM, Steve Gough <address@hidden> wrote:
>>> Hi All,
>>>
>>> I am interested in analyzing the doppler shift of a transmitted signal.
>>>
>>> As a first step, I want to see if I can capture hand movements in a
>>> Waterfall sink for an audio signal (tone). For that I use a flow graph like
>>> the attached screenshot based on
>>> https://github.com/ckuethe/gnuradio-examples/tree/master/doppler_sonar and
>>> https://www.youtube.com/watch?v=9trGfdcMPtk&noredirect=1.
>>>
>>> I don't observe any doppler shift when I move my hand/walk in the vicinity.
>>> I can see the FFT plots change in shape on motion, but nothing is observed
>>> on the Waterfall sink.
>>>
>>> Could you please tell me if I am missing something here?
>>>
>>> The observed waterfall spectrogram is also attached.
>>>
>>> Thanks,
>>> Steve
>>>
>>> _______________________________________________
>>> Discuss-gnuradio mailing list
>>> address@hidden
>>> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
>>>
>>
>>
>>
>> --
>> GDB has a 'break' feature; why doesn't it have 'fix' too?
>> <Screenshot_2016-10-21_12-46-58.png>
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-- 
GDB has a 'break' feature; why doesn't it have 'fix' too?