Re: [Discuss-gnuradio] Specify taps for 'FFT_Filter' using function call to 'GLFSR Source'

[Cinaed Simson]

On 09/28/2017 01:21 PM, Cinaed Simson wrote:
> On 09/27/2017 12:07 AM, Marcus Müller wrote:
>> Hi Cinaed,
>>
>> interestingly, period() gives me 0b(degree ones) all the time, so I'm
>> not sure we don't see a bug there.
> 
> I looped over degree in range(1,33)
> 
>   src=digital.glfsr_source_f(degree,True,mask,seed)
>   src=digital.glfsr_source_b(degree,True,mask,seed)
> 
> and I consistently get a period of degree**2-1 both float and byte types.

Opps, the period was

   period=2**degree-1

-- Cinaed

> 
> But I did notice running the GLFSR source in a flow graph with type Byte
> generates an asymmetric frequency spectrum about the center frequency.
> 
> There are persistent dips in the amplitude at roughly -1.27 Hz and -2.58
> Hz which aren't present in the positive frequencies - and are not
> present in the spectrum for type Float.
> 
> -- Cinaed
> 
> 
>>
>> Best regards,
>>
>> Marcus
>>
>>
>> On 09/27/2017 12:01 AM, Cinaed Simson wrote:
>>> Try
>>>
>>>   from gnuradio import digital as digital
>>>   src=digital.glfsr_source_f(13,False,0x0000100D,0xA5A5)
>>>   src.period()
>>>
>>> src has type <gr_block glfsr_source_f (0)>
>>>
>>> Unfortunately, I don't know enough to be able to convert to an array of
>>> floats need for filter taps.
>>>
>>> -- Cinaed
>>>
>>>
>>> On 09/26/2017 05:45 PM, Chad Spooner wrote:
>>>> All:
>>>>
>>>> I've got a working signal generator in GRC that uses the FFT Filter
>>>> block. In the Taps
>>>> field of this block, I've hand-entered a length-31 sequence that is an
>>>> MLSR sequence.
>>>> These sequences can be generated using the GRC block GLFRS Source as well.
>>>>
>>>> What I would like to do is call GLFSR from within  the FFT Filter Taps
>>>> field with arguments
>>>> that depend on a Parameter. Specifically, the Degree parameter of GLFSR
>>>> would
>>>> be tied to a Parameter in the flowgraph.
>>>>
>>>> I've been searching around the web for a way to do this, but I can't
>>>> seem to find how
>>>> to call things like GLFSR as opposed to using the GLFSR block in GRC. My
>>>> Google
>>>> searches do not seem to contain the correct keywords to get me to the
>>>> help I need.
>>>>
>>>> I'd appreciate any hints, especially links to explanations on the web.
>>>>
>>>> Thanks!
>>>>
>>>> Chad
>>>>
>>>> -- 
>>>> Chad M. Spooner
>>>> NorthWest Research Associates
>>>> 301 Webster Street
>>>> Monterey, CA 93940
>>>> address@hidden
>>>> 831 582 4904
>>>> cyclostationary.blog
>>>>
>>>>
>>>>
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