[Discuss - gnuradio] Callback function on OOT Python blocks

[Jose Ruvalcaba]

Hello,

I am trying to setup a callback function on an python OOT Block I made with
GNU radio 3.7. I am trying to do this so I can manually change the value of
my parameter using a slider.

In the XML file of my OOT block I have added a statement that looks like
this: set_variable_name($variable_name) 
However, I was wondering, Do I need to add any other "callback" commands to
my python file? Or is this callback line in the XML file enough in order to
have variables change in my python OOT Block. Any tips would be appreciate.


Thank you,

Jose Ruvalcaba

Re: GMSK bandwidth

[Brian Padalino]

On Wed, May 6, 2020 at 7:48 PM Artur Nogueira  wrote:

> Hello guys,
>
> I'm trying to generate a GMSK signal in accordance to the GSM
> specifications. To do so, I've been trying with both "GMSK Mod" and "GMSK
> Modulator" blocks, the last one with the following parameters:
>
> [image: image.png]
>
> To set these parameters, I considered (i) a sufficiently high base-band
> sampling rate (samples/symbol) in order to avoid aliasing; (ii) the
> well-known 0.3 BT product and (iii) a 156 bits GSM pulse, i.e. 1 time slot
> (I considered that GMSK provides 1 bit/symbol).
>
> Nevertheless, my signals have a bandwidth which is much larger than the
> 200 kHz requirement.
> What am I doing wrong?
>

I think you want something more like 3 symbols for your pulse duration.
Not 156.

Brian

>

GMSK bandwidth

[Artur Nogueira]

Hello guys,

I'm trying to generate a GMSK signal in accordance to the GSM
specifications. To do so, I've been trying with both "GMSK Mod" and "GMSK
Modulator" blocks, the last one with the following parameters:

[image: image.png]

To set these parameters, I considered (i) a sufficiently high base-band
sampling rate (samples/symbol) in order to avoid aliasing; (ii) the
well-known 0.3 BT product and (iii) a 156 bits GSM pulse, i.e. 1 time slot
(I considered that GMSK provides 1 bit/symbol).

Nevertheless, my signals have a bandwidth which is much larger than the 200
kHz requirement.
What am I doing wrong?

Best regards,
Artur

Behavior of sample scheduler with hardware RX/TX (USRP)

[Lukas Haase]

Hi,

I am discussing this question on usrp-users right now but I think this may 
actually be a question regarding the scheduler in gnuradio.
I have the following simple flow graph (USRP in loopback configuration):

 +-+
 +---+   | |
 | Cosine Source |---+-->| QT GUI  |
 +---+   |+---+  +-+ |  Freq   |
 `--->| USRP Sink |  | USRP Source |>|  Sink   |
  +---+  +-+ | |
 +-+

Both Source+Sink use the same motherboard which resets its time as follows:
  self.uhd_usrp_sink_0.set_time_unknown_pps(uhd.time_spec())

Furthermore, I let streaming start at the same time:

  self.uhd_usrp_sink_0.set_start_time(uhd.time_spec(1.0))
  self.uhd_usrp_source_0.set_start_time(uhd.time_spec(1.0))

The very puzzling result: I only get a string of L's, most likely from USRP 
Sink, indicating that samples arrived too late (later than 1s).

I can "fix" this in two ways:

1.) I break the connection from "Cosine Source" to "QT Freq Sink". Then both 
input and output sample streams are independent

2.) I let USRP Sink streaming start *later*:
  self.uhd_usrp_sink_0.set_start_time(uhd.time_spec(1.1))
  self.uhd_usrp_source_0.set_start_time(uhd.time_spec(1.0))

Fix #1 I cannot use because I need both signals in my algorithm. Fix #2 is 
unsatisfying because it feels unreliable and if I add blocks like "Skip Head" 
with a sufficiently high number (which I want to use to align my signals within 
gnuradio" I receive "U" (Underrun, USRP Sink did not receive enough samples 
from gnuradio).


My question is: How does the scheduler work exactly if we call the work 
functions of these blocks work1, work2, work3, work4?
In which time order are they called and what makes it to break the above 
diagram when USRP Source/Sink start streaming at the same time?


Thanks,
Lukas

Gnuradio error

[Vincenzo Mone]

Please I still have problems when I run a grc file.

I have loaded the grc file in the gnuradio and and do not get any

Red blocks but when I go to play it, I get errors.

Here is the log I see on the bottom side of gnuradio:

 

 

 

Loading: "/home/enzo/gr-fcdproplus/example/fmfcdpp.grc"

>>> Done

 

Generating: '/home/enzo/gr-fcdproplus/example/FMRadio.py'

 

Executing: /usr/bin/python3 -u /home/enzo/gr-fcdproplus/example/FMRadio.py

 

Traceback (most recent call last):

  File "/usr/lib/python3/dist-packages/fcdproplus/fcdproplus_swig.py", line
14, in swig_import_helper

return importlib.import_module(mname)

  File "/usr/lib/python3.6/importlib/__init__.py", line 126, in
import_module

return _bootstrap._gcd_import(name[level:], package, level)

  File "", line 994, in _gcd_import

  File "", line 971, in _find_and_load

  File "", line 955, in _find_and_load_unlocked

  File "", line 658, in _load_unlocked

  File "", line 571, in module_from_spec

  File "", line 922, in create_module

  File "", line 219, in
_call_with_frames_removed

ImportError: /usr/lib/libgnuradio-fcdproplus.so.3.8.0: undefined symbol:
hid_exit

 

During handling of the above exception, another exception occurred:

 

Traceback (most recent call last):

  File "/home/enzo/gr-fcdproplus/example/FMRadio.py", line 39, in 

import fcdproplus

  File "/usr/lib/python3/dist-packages/fcdproplus/__init__.py", line 45, in


from .fcdproplus_swig import *

  File "/usr/lib/python3/dist-packages/fcdproplus/fcdproplus_swig.py", line
17, in 

_fcdproplus_swig = swig_import_helper()

  File "/usr/lib/python3/dist-packages/fcdproplus/fcdproplus_swig.py", line
16, in swig_import_helper

return importlib.import_module('_fcdproplus_swig')

  File "/usr/lib/python3.6/importlib/__init__.py", line 126, in
import_module

return _bootstrap._gcd_import(name[level:], package, level)

ModuleNotFoundError: No module named '_fcdproplus_swig'

 

>>> Done (return code 1)

 

Any help?

Also please I have heard that I have to set the device name but did not
understand how to do it.

 

arecord -L

and I got this result:

 

default

Playback/recording through the PulseAudio sound server

null

Discard all samples (playback) or generate zero samples (capture)

pulse

PulseAudio Sound Server

sysdefault:CARD=AudioPCI

Ensoniq AudioPCI, ES1371 DAC2/ADC

Default Audio Device

front:CARD=AudioPCI,DEV=0

Ensoniq AudioPCI, ES1371 DAC2/ADC

Front speakers

iec958:CARD=AudioPCI,DEV=0

Ensoniq AudioPCI, ES1371 DAC2/ADC

IEC958 (S/PDIF) Digital Audio Output

dmix:CARD=AudioPCI,DEV=0

Ensoniq AudioPCI, ES1371 DAC2/ADC

Direct sample mixing device

dsnoop:CARD=AudioPCI,DEV=0

Ensoniq AudioPCI, ES1371 DAC2/ADC

Direct sample snooping device

hw:CARD=AudioPCI,DEV=0

Ensoniq AudioPCI, ES1371 DAC2/ADC

Direct hardware device without any conversions

plughw:CARD=AudioPCI,DEV=0

Ensoniq AudioPCI, ES1371 DAC2/ADC

Hardware device with all software conversions

sysdefault:CARD=V20

FUNcube Dongle V2.0, USB Audio

Default Audio Device

front:CARD=V20,DEV=0

FUNcube Dongle V2.0, USB Audio

Front speakers

surround21:CARD=V20,DEV=0

FUNcube Dongle V2.0, USB Audio

2.1 Surround output to Front and Subwoofer speakers

surround40:CARD=V20,DEV=0

FUNcube Dongle V2.0, USB Audio

4.0 Surround output to Front and Rear speakers

surround41:CARD=V20,DEV=0

FUNcube Dongle V2.0, USB Audio

4.1 Surround output to Front, Rear and Subwoofer speakers

surround50:CARD=V20,DEV=0

FUNcube Dongle V2.0, USB Audio

5.0 Surround output to Front, Center and Rear speakers

surround51:CARD=V20,DEV=0

FUNcube Dongle V2.0, USB Audio

5.1 Surround output to Front, Center, Rear and Subwoofer speakers

surround71:CARD=V20,DEV=0

FUNcube Dongle V2.0, USB Audio

7.1 Surround output to Front, Center, Side, Rear and Woofer speakers

iec958:CARD=V20,DEV=0

FUNcube Dongle V2.0, USB Audio

IEC958 (S/PDIF) Digital Audio Output

dmix:CARD=V20,DEV=0

FUNcube Dongle V2.0, USB Audio

Direct sample mixing device

dsnoop:CARD=V20,DEV=0

FUNcube Dongle V2.0, USB Audio

Direct sample snooping device

hw:CARD=V20,DEV=0

FUNcube Dongle V2.0, USB Audio

Direct hardware device without any conversions

plughw:CARD=V20,DEV=0

FUNcube Dongle V2.0, USB Audio

Hardware device with all software conversions

 

But did not understood what to do.

Anybody can tell me also exactly what to do?

Thanks in advance

 

 

73 de Enzo IK8OZV
EasyLog 5 BetaTester
EasyLog PDA BetaTester
WinBollet BetaTester
D.C.I. CheckPoint Regione Campania
Skype: ik8ozv8520




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[GSoC20] GRC: View only mode (Secure): Blog updates

[Arpit Gupta]

Hi everyone,

I am really excited about doing some awesome work with GNU Radio this
summer and I hope that my work will be a nice extension to the GNU Radio
project.
I'll be posting weekly blogs about the current state of my project and will
also remain in frequent touch with the mentors throughout the program. Here
is the link  to my blog.

Congratulations Alekh for selection in GSoC. I wish you all the best for
your project.
Thank you, everyone, for your constant support throughout the selection
procedure.

Regards,
Arpit Gupta
Indian Institute of Technology Roorkee