GNU Radio modules and its contents

[GNU Radio, the Free & Open-Source Toolkit for Software Radio]

Hi Community,
I am quite new to GNU Radio ecosystem and I am wondering how you guys are
getting to know about many functions that the library and submodules offer?
For example, it's relatively easy to make a flowgraph based on the blocks
but the blocks (and hided object behind them) are one thing but the other
thing are variety of functions in each of the module e.g. gr-digital. I
didn't know about the digital.psk_4() function that returns mappings from
symbols to bit words before I run the examples from the gr-digital module.
I was always putting those values as lists by hand, cause I didn't
know that such a function exists. So my main question is: how to get to
know about a variety of functions/classes that GNU Radio provides? Should I
read the source code of each module starting in lib/ and /python directory
or is there a less cumbersome way?
Thanks
-- 

Marcin Puchlik

DSP Engineer



mobile +48 504 716 843


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05-500 Piaseczno/near Warsaw

Poland, EU

http://is-wireless.com

Re: GNU Radio modules and its contents

[Marcus D. Leech]

On 2022-02-09 08:09, Marcin Puchlik via GNU Radio, the Free & 
Open-Source Toolkit for Software Radio wrote:

Hi Community,
I am quite new to GNU Radio ecosystem and I am wondering how you guys 
are getting to know about many functions that the library and 
submodules offer? For example, it's relatively easy to make a 
flowgraph based on the blocks but the blocks (and hided object behind 
them) are one thing but the other thing are variety of functions in 
each of the module e.g. gr-digital. I didn't know about the 
digital.psk_4() function that returns mappings from symbols to bit 
words before I run the examples from the gr-digital module. I was 
always putting those values as lists by hand, cause I didn't know that 
such a function exists. So my main question is: how to get to know 
about a variety of functions/classes that GNU Radio provides? Should I 
read the source code of each module starting in lib/ and /python 
directory or is there a less cumbersome way?

Thanks
--

Marcin Puchlik

DSP Engineer



https://www.gnuradio.org/doc/doxygen/page_digital.html#digital_python_helpers_psk

That general area should help.

Low sample rate hardware

[vitt...@pm.me]

Good evening everybody
I'm looking for a sampling device, GNURADIO compatible, with low sample rate ( 
max 50 KHz ) AND frequency response down to 1 Hz, so sound cards aren't the 
choice.
Any suggestion ???
Tnx in advance :-)

Vittorio

fingerprint: fb5f492a54e016c632c933d3ee4b7e38203c79ca

Sent with [ProtonMail](https://protonmail.com/) Secure Email.

Re: Low sample rate hardware

[Fabian Schwartau]

Hi Vittorio,

often you can remove/short the de-coupling caps on soundcards, making 
them work down to DC. Maybe thats the easy/simple solution.


Best regards,
Fabian

Am 09.02.22 um 19:07 schrieb vitt...@pm.me:

Good evening everybody
I'm looking for a sampling device, GNURADIO compatible,  with low sample 
rate ( max 50 KHz ) AND frequency response down to 1 Hz, so sound cards 
aren't the choice.

Any suggestion ???
Tnx in advance :-)

Vittorio


fingerprint: |fb5f492a54e016c632c933d3ee4b7e38203c79ca|

Sent with ProtonMail  Secure Email.

Re: Low sample rate hardware

[Albin Stigö]

For low budget modify the low pass filter of a sound card.

On Wed, Feb 9, 2022, 15:27 vitt...@pm.me  wrote:

> Good evening everybody
> I'm looking for a sampling device, GNURADIO compatible,  with low sample
> rate ( max 50 KHz ) AND frequency response down to 1 Hz, so sound cards
> aren't the choice.
> Any suggestion ???
> Tnx in advance :-)
>
> Vittorio
>
>
> fingerprint: fb5f492a54e016c632c933d3ee4b7e38203c79ca
>
> Sent with ProtonMail  Secure Email.
>
>

Re: Low sample rate hardware

[Fabian Schwartau]

Besides hardware-hacking a sound card, you may also use some USB 
oscilloscope, in combination with sigrok-cli and its --continuous flag. 
I have never used this, but I guess there is a way to stream this data 
to gnuradio. Note that not every hardware supports this --continuous 
feature! Sadly the Wiki does not tell you which one does, so you have to 
look into the source code:

https://github.com/sigrokproject/libsigrok/tree/master/src/hardware
and search for the flag SR_CONF_CONTINUOUS to find a working hardware. 
Also, the sigrok.org website is down since a few days and the wiki is 
not available, which would help to match a drivers name to an actual device.


Fabian

Am 09.02.22 um 19:07 schrieb vitt...@pm.me:

Good evening everybody
I'm looking for a sampling device, GNURADIO compatible,  with low sample 
rate ( max 50 KHz ) AND frequency response down to 1 Hz, so sound cards 
aren't the choice.

Any suggestion ???
Tnx in advance :-)

Vittorio


fingerprint: |fb5f492a54e016c632c933d3ee4b7e38203c79ca|

Sent with ProtonMail  Secure Email.

Re: Low sample rate hardware

[Alex Roberts]

EDN recently published an article on using an external input buffer to
extend the low range response of sounds cards:

“Input buffer and attenuator for sound card oscilloscopes extends low-end
frequency response”. Stephen Woodward.
https://www.edn.com/input-buffer-and-attenuator-for-sound-card-oscilloscopes-extends-low-end-frequency-response/


They have an example circuit and describe how it compensates for the AC
coupling capacitors.

On Wednesday, February 9, 2022, Fabian Schwartau  wrote:

> Besides hardware-hacking a sound card, you may also use some USB
> oscilloscope, in combination with sigrok-cli and its --continuous flag. I
> have never used this, but I guess there is a way to stream this data to
> gnuradio. Note that not every hardware supports this --continuous feature!
> Sadly the Wiki does not tell you which one does, so you have to look into
> the source code:
> https://github.com/sigrokproject/libsigrok/tree/master/src/hardware
> and search for the flag SR_CONF_CONTINUOUS to find a working hardware.
> Also, the sigrok.org website is down since a few days and the wiki is not
> available, which would help to match a drivers name to an actual device.
>
> Fabian
>
> Am 09.02.22 um 19:07 schrieb vitt...@pm.me:
>
>> Good evening everybody
>> I'm looking for a sampling device, GNURADIO compatible,  with low sample
>> rate ( max 50 KHz ) AND frequency response down to 1 Hz, so sound cards
>> aren't the choice.
>> Any suggestion ???
>> Tnx in advance :-)
>>
>> Vittorio
>>
>>
>> fingerprint: |fb5f492a54e016c632c933d3ee4b7e38203c79ca|
>>
>> Sent with ProtonMail  Secure Email.
>>
>>
>
>

Re: Low sample rate hardware

[wk]

Good evening everybody
I'm looking for a sampling device, GNURADIO compatible, with low 
sample rate ( max 50 KHz ) AND frequency response down to 1 Hz, so 
sound cards aren't the choice.

Any suggestion ???
Tnx in advance :-)

Vittorio



Some time ago I was using Analog Devices' ADALM2000 demo/measurement 
module. It looks like ADALM PLUTO but is a combination of 2-channel 
oscilloscope and arbitrary generator.
It has two 1Mohm DC/AC coupled inputs. Usually it is used with 
dedicated software from
AD, named scopy, but there are libraries and drivers for Gnu Radio. 
Sampling speed is up

to 10MHz so it should be more than enough.

--
Wojciechh