controlling Digital I/O from GRC



I would like to control the digital I/O (8 of the lines) of the USRP X300 from GNU Radio Companion.  Has anyone attempted this?


From reading the gpio_api online, it sounds like I need to discover the digital I/O by using the get_gpio_banks function in multi_usrp, and then use usrp_x300->set_gpio_attr() to control the digital I/O.  Is there a way to do this from GNU Radio Companion?  My experience thus far has been dragging and dropping blocks in GRC.  If I make a block from scratch, I am assuming I will need to pass the usrp_x300 handle into the block to make the calls (I don’t have experience making my own GRC blocks).  I would also need a user interface to assign the value for the output of the digital I/O.


Any recommendations on where to begin?










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Anton Komarov | 24 Apr 16:43 2014

Control audio recording using function probe

Hi, have an issue with controlling audio recording with function probe, that measures signal level. A variable 'muted' is set to 0 or 1 depending on current  rf power threshold, and depending on muted state recording starting and stops. I suppose i would get continous file when level is above the threshold, but in fact script generatates files every second (file name contains current time), because filename variable updates continously and wav sink opens new files or rewrites old ones. So glad to hear your suggestions to solve this task.
public PGP key

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Tom Rondeau | 24 Apr 18:32 2014


Testing mail server. Seems server wide problem.


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Ed Criscuolo | 24 Apr 17:32 2014

Finding max index in a vector

How do I find the index of the max value in a vector from GRC?
The max_xx block outputs the max value, but not its
index, despite what it's documentation says:

"Data is passed in as a vector of length  from multiple input sources. 
It will look through these streams of  data items and output two 
streams. Stream 0 will contain the index value in the vector where the 
maximum value occurred."

I checked the code template for max (GR v3.7.3), and it doesn't even
seem to retain the index of the max it reports.

 <at> (^.^) <at>   Ed
Software RadioUSA | 25 Apr 03:02 2014

GnuRadio/USRP1 application compatible HandHeld Wideband 33 Megahertz – 4.4 Gigahertz Software Defined Radio

Since this device utilizes the LibUSRP driver, all USRP1 Applications should be able to work with this SDR device.

This handheld wideband SDR device fits comfortably within the dimensions of the BladeRF, but utilizes USB 2.0 to AVOID well known USB 3.0 Issues with Radio Waves.

Technical Specifications:

• Wide RF range 33MHz-4400Mhz *(1)

• 64MSPS 14bit AD
• 128MSPS 12bit DA

• Wide range supply voltage from DC 8V-24V.
• USB 2.0 H/S connectivity provide max 8M sampling bandwidth(16bit).
• Integrated accuracy ±0.5ppm <at> 25℃ TCXO andstability is ±1.0ppm (-20℃~70℃)
• Flexible PLL regenerated clock for AD/DA to get more choice.
• Impact PCBA form factor 118.18*76.68 mm

More technical information can be found here: 

Works with the following software from within windows:

Windows GSM Scanner ( Working Nicely )


Windows GSM Base Station ( Alpha Version Software)


www.SoftwareRadio.us for more information.

E-Mail:  SoftwareRadioUSA <at> Gmail.com
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qin 1921 | 24 Apr 05:57 2014

coding bug in gr-channels/lib/flat_fader_impl.cc

I believe there is a bug in file gr-channels/lib/flat_fader_impl.cc, line 67

according to Eq.4 of paper "Improved Models for the Generation of Multiple Uncorrelated Rayleigh Fading Waveforms" published on IEEE COMMUNICATIONS LETTERS, VOL. 6, NO. 6, JUNE 2002, 

that line should be changed from:

         float alpha_n = (2*M_PI*n - M_PI + d_theta)/4*d_N;

        float alpha_n = (2*M_PI*n - M_PI + d_theta)/(4*d_N);

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golorkhameshta | 24 Apr 05:33 2014

Announcing NEWSDR in Boston on Friday June 6

*                     Fourth-Annual                     *
*                                                       *
*     New England Workshop on Software-Defined Radio    *
*                      NEWSDR 2014                      *
*                                                       *
*         Friday, 6 June 2014, 8:30 AM - 5:30 PM        *
*     Boston University, Photonics Center, 9th Floor    *
*                    Boston, MA, USA                    *
*                                                       *
*              http://www.sdr-boston.org/               *


You are cordially invited to the 2014 New England Workshop
on Software Defined Radio (NEWSDR 2014), which is the fourth
installment of an annual series of workshops organized by
the Boston SDR User Group (SDR-Boston). This year NEWSDR
will be held on the 9th Floor of the Photonics Center of
Boston University on Friday 6 June 2014.

NEWSDR 2014 also features two technical oral presentation
sessions, several technical poster presentation sessions,
several hardware  demonstrations and SDR test-beds, and an
industry panel discussion, all focusing on the latest
advances in software-defined radio and/or cognitive radio

Please forward this message to your colleagues that may be
interested in NEWSDR'14.  We hope to see you there!


  * Professor Jeffrey Reed, Virginia Tech


  * Mr. Marcus Leech, Science Radio Laboratories / Shirleys Bay Radio Astronomy Consortium

  * Dr. Zoran Zvonar, MediaTek Wireless Inc.


  * The MathWorks Inc.
  * National Instruments / Ettus Research
  * Analog Devices Inc.
  * MediaTek Wireless Inc.
  * Boston University, Center for Information and Systems Engineering


  * Oral and poster presentations are now being solicited
  * See link at the bottom of this email to submit your abstract online!


  * Free with advanced online pre-registration (lunch and parking included)
  * Space is limited, so register soon!
  * See link at the bottom of this email to register online.


The latest information of this event can be found at the following
website: http://www.sdr-boston.org/ (under&nbsp;"Workshops > NEWSDR 2014").





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Sara Chérif | 24 Apr 04:42 2014


 I run  the file "ofdm_txrx.py" from terminal using command ./ofdm_txrx.py
But I got errors !!! why ?

Thanks in advance ! Here is the output on terminal: 

./ofdm_txrx_me.py: line 26:
OFDM Transmitter / Receiver hier blocks.

For simple configurations, no need to connect all the relevant OFDM blocks
to form an OFDM Tx/Rx--simply use these.
: No such file or directory
./ofdm_txrx_me.py: line 31: import: command not found
from: can't read /var/mail/gnuradio
./ofdm_txrx_me.py: line 33: import: command not found
from: can't read /var/mail/utils
./ofdm_txrx_me.py: line 36: try:: command not found
from: can't read /var/mail/gnuradio
from: can't read /var/mail/gnuradio
from: can't read /var/mail/gnuradio
./ofdm_txrx_me.py: line 41: except: command not found
./ofdm_txrx_me.py: line 43: import: command not found
./ofdm_txrx_me.py: line 44: import: command not found
./ofdm_txrx_me.py: line 45: import: command not found
./ofdm_txrx_me.py: line 47: _def_fft_len: command not found
./ofdm_txrx_me.py: line 48: _def_cp_len: command not found
./ofdm_txrx_me.py: line 49: _def_frame_length_tag_key: command not found
./ofdm_txrx_me.py: line 50: _def_packet_length_tag_key: command not found
./ofdm_txrx_me.py: line 51: _def_packet_num_tag_key: command not found
./ofdm_txrx_me.py: line 53: syntax error near unexpected token `('
./ofdm_txrx_me.py: line 53: `_def_occupied_carriers = (range(-26, -21) + range(-20, -7) + range(-6, 0) + range(1, 7) + range(8, 21) + range(22, 27),)'

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Philip Balister | 23 Apr 22:06 2014

ICE for emebedded builds

Tom and I have put some effort into integrating Ice into OE so we can
support control port builds.

It will take a bit before I can get the updates needed into meta-oe, so
I have pushed a couple of branches for people to poke at. They will go
away once I can push the ice stuff into meta-sdr (which is bloacked by
ice going into meta-oe)

Anyway, have fun:



Nasi | 23 Apr 21:01 2014

OFDM benchmarking with UHD

Hi all,

(Ubuntu 1304 gnuradio 3.7)

I want to test OFDM in gr_digital using tx_ofdm.grc and rx_ofdm.grc. (simultaneously using usrp n200 devices)
Where are UHD source and sink in that flow g.?

Since I do not want to add them myself, I want to see how the original system works.
Do you know where I can find such a thing?

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julian | 23 Apr 18:02 2014

installing gnuradio e110

Hello, i'm new in gnuradio and i want to update all needed to program this
device the e110.

how it says in:
i have downloaded the latest image e1xx-003 and store to sd with the
MakeEttusSDCard.legacy.sh.(the MakeEttusSDCard.sh didn´t work for me).
i updated the uhd and then the FPGA firmaware following all instructions and
everything OK.

but the problem is when i want to update the gnuradio,if i run:

opkg remove --force-depends gnuradio gnuradio-dev gnuradio-examples
git clone http://gnuradio.org/git/gnuradio.git gnuradio.git
# cd gnuradio.git
# mkdir build
# cd build
# make
i have this error:

[ 13%] Built target pygen_gnuradio_runtime_python_gnuradio_gru_21325
[ 13%] Generating __init__.pyc, pmt_to_python.pyc
Traceback (most recent call last):
  File "/home/root/gnuradio.git/build/python_compile_helper.py", line 6, in
<mod                    ule>
    py_compile.compile(file=src, cfile=gen, doraise=True)
  File "/usr/lib/python2.6/py_compile.py", line 129, in compile
    raise py_exc
py_compile.PyCompileError: SyntaxError: ('invalid syntax',
.git/gnuradio-runtime/python/pmt/pmt_to_python.py', 67, 88, '   
(numpy.float32,                    pmt.init_f32vector, float,
pmt.f32vector_elements, pmt.is_f32vector),\n'))

make[2]: *** [gnuradio-runtime/python/pmt/__init__.pyc] Error 1
make[1]: ***
on_pmt_a42cc.dir/all] Error 2
make: *** [all] Error 2

some idea?.
looks like there is some syntax error in the code downloaded but is not


best regards,

View this message in context: http://gnuradio.4.n7.nabble.com/installing-gnuradio-e110-tp47730.html
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