Hello,
I have ubuntu 12.04 and GNURadio 3.6.2. I was trying to run some older scripts
which uses the USRP. These scripts were made with GNURadio Companion about 3
years ago, and then I added some extra menu options by manually editing the
python script made by GRC.
Unfortunately when I run t
Hello all,
I have an older version of gnuradio (pre 3.6.2) on one of my laptops. When I
run a simple script I made in GRC which has a USRP source block and a WAV file
sink block it seems to work fine. With nothing connected on the LFRX RF
connectors, I get a signal with basically 0 amplitude
Hello all,
I am using a USRP1 and an LFTX daughtercard and Ubuntu 12.04.
I am having an issue with a simple GRC script I made which has three blocks.
A WAV file source connects to a resampler block and then to the UHD USRP sink.
When I run the script I get a single underun right at the start of
?
Thanks, -Tom
From: Josh Blum
To: discuss-gnuradio@gnu.org
Sent: Monday, November 12, 2012 1:03 PM
Subject: Re: [Discuss-gnuradio] UHD Underrun with Wav File Source and USRP Sink
On 11/11/2012 01:21 PM, Tom Hendrick wrote:
> Hello all,
>
> I a
-gnuradio] UHD Underrun with Wav File Source and USRP Sink
On 11/12/2012 02:10 PM, Tom Hendrick wrote:
>
>
> Hello Josh,
>
> Thanks for the suggestion. Yes I had zero padded the file with about 1
> second of zero signal prior to the signal I want to transmit. I had stil
As an additional check, I reduced the signal amplitude further in the WAV file
to make sure there is no truncation. I still see the same two underruns at the
start of running the script.
Thanks, - Tom
From: Tom Hendrick
To: "discuss-gnuradio@gn
Does anyone have some ideas on what else I can try right now? I'm out of ideas
on what is causing the underruns at the start of running the script that reads
the WAV file and outputs to the USRP LFTX.
Thank you, -Tom
From: Tom Hendrick
To: Tom Hen
Hello all,
I'm seeing a lot of latency in streaming from a webcam with GNURadio and the
USRP.
The transmit chain looks like:
ffmpeg | ./modulator > tx.fifo &
then I run
sudo ./usrp_stream_tx.py
modulator is an external code I am running that is not part of gnuradio.
uhd_stream_tx is a python s
Hello Josh,
The transmitter sends data when there is enough to fill a packet. The packets
are flushed about every 200msec consistently. The ffmpeg encoder seems to have
a continuous output that is pretty steady since it is encoding webcam images at
a pretty reasonably constant bitrate with the
Hz so the USRP is run at 1MS/s rates.
Thank you, Tom
From: Matt Ettus
To: Tom Hendrick
Cc: "j...@ettus.com" ; "discuss-gnuradio@gnu.org"
Sent: Wednesday, January 23, 2013 10:34 AM
Subject: Re: [Discuss-gnuradio] Unknown cause of Laten
x27;m not sure if there
even is a solution to this that I could easily implement with GRC.
Thanks again, Tom
From: Tom Hendrick
To: Matt Ettus
Cc: "discuss-gnuradio@gnu.org" ; "j...@ettus.com"
Sent: Wednesday, January 23, 2013 10:40
45kbps how come I don't
see the latency buildup with netcat and a cat5e cable? This led me to believe
it was a problem with my gnuradio setup.
Thanks again, Tom
From: Matt Ettus
To: Tom Hendrick
Cc: "j...@ettus.com" ; "discuss-gnura
k you, Tom
From: Josh Blum
To: Tom Hendrick
Cc: Matt Ettus ; "discuss-gnuradio@gnu.org"
Sent: Wednesday, January 23, 2013 1:52 PM
Subject: Re: [Discuss-gnuradio] Unknown cause of Latency with USRP
On 01/23/2013 02:29 PM, Tom Hendrick wrote:
> Hello Matt, I went back an
double check to make sure the
transmitter is indeed flushing out data only once a packet is made.
Thank you, Tom
________
From: Josh Blum
To: Tom Hendrick
Cc: "discuss-gnuradio@gnu.org"
Sent: Thursday, January 24, 2013 2:36 PM
Subject: Re: [Discuss-gnuradio] U
Hello all,
I've done some troubleshooting on an underrun problem I was having where the
signal seemed to get broken up with
random gaps. The underruns happen when I set the data rate of my stream
lower than the external modulator/demodulator's transmission rate. The
external modulator code
Hello,
I think its possible some of the underrun issues I mentioned in my other posts
(where random gaps occur inside a block of data sent to the USRP when set the
USRP sampling frequency any lower than 1 MHz,) may be solved by tweaking
nout_items and buffer related settings.
For GNURadio 3.6.
k you, Tom
From: Tom Rondeau
To: Tom Hendrick
Cc: "discuss-gnuradio@gnu.org"
Sent: Wednesday, February 6, 2013 2:36 PM
Subject: Re: [Discuss-gnuradio] Changing Nout_items and Buffer Settings for
GNURadio 3.6.2
On Wed, Feb 6, 2013 at 1:34 PM,
From: Tom Hendrick
To: Tom Rondeau
Cc: "discuss-gnuradio@gnu.org"
Sent: Wednesday, February 6, 2013 2:54 PM
Subject: Re: [Discuss-gnuradio] Changing Nout_items and Buffer Settings for
GNURadio 3.6.2
Hi Tom,
I appreciate your response and information
Hello all,
I am trying to make the USRP1 work with 4 independent real signal channels (not
IQ) using two RX daughterboards. In the older versions of GNURadio I was able
to make this work with a custom block I had found in a repository or from
somebody on the mailing list.
I am using GRC to
Oh ok I will try that out not sure why I didn't come across that in my search.
Thanks so much Marcus!
-Tom
From: Marcus D. Leech
To: discuss-gnuradio@gnu.org
Sent: Tuesday, February 19, 2013 11:13 AM
Subject: Re: [Discuss-gnuradio] USRP1 4 Channel Subdev I
is is
possible but I would like to not have to boot into an older ubuntu version when
I need 4 real channels. The only thing that comes to mind is to adjust
noutput_items and I tried this but it didn't eliminate the overruns.
Thank you, -Tom
____
From: Tom He
right way to change those
settings?
What are the default values in case I need to set them back to what they were?
I couldn't find this anywhere in the UHD documentation.
Thank you, - Tom
____
From: Marcus D. Leech
To: Tom Hendrick
Cc: "discuss-gnuradio@g
t 1Ms/s for each
of the 4 USRP channels.
Is there anything else I can try? Do I need to also alter the send_frame_size
and num_send_frames in the uhd_usrp_probe calls?
Thank you, Tom
From: Josh Blum
To: Tom Hendrick ; "Discuss-gnuradio@gnu.org"
-Tom
From: Tom Hendrick
To: "j...@ettus.com" ; "Discuss-gnuradio@gnu.org"
Sent: Thursday, February 21, 2013 2:20 PM
Subject: Re: [Discuss-gnuradio] USRP1 4 Channel Subdev Issue
Thanks Josh.
I've tried some different combinations of uhd_us
Hello all,
I've had trouble making a 4 channel USRP samples at 1Ms/s write to file at 500
kS/s with ubuntu 12.04 and libuhd. I am getting several overruns and I had
tried adjusting some of the parameters using usrd_probe_devices but with no
success. I have a laptop with a duo core centrino pro
rmance on older machines
On 03/01/2013 04:51 PM, Tom Hendrick wrote:
> Hello all,
>
> I've had trouble making a 4 channel USRP samples at 1Ms/s write to file at
> 500 kS/s with ubuntu 12.04 and libuhd. I am getting several overruns and I
> had tried adjusting some of the para
From: Josh Blum
To: Tom Hendrick
Cc: "discuss-gnuradio@gnu.org"
Sent: Saturday, March 2, 2013 9:18 AM
Subject: Re: [Discuss-gnuradio] LibUSRP vs LibUHD Performance on older machines
On 03/01/2013 05:16 PM, Tom Hendrick wrote:
> Josh,
>
> Thank you so much for the sug
Thanks Marcus, I also thought the same thing. Just to be safe I had run the
uhd_usrp_probe call with the default settings before trying the suggestions
from Josh.
From: Marcus D. Leech
To: discuss-gnuradio@gnu.org
Sent: Saturday, March 2, 2013 3:25 PM
Subj
Hi Josh,
Would you happen to suggest any more setting changes I could try before just
deciding I need to depend on the older libusrp/gnuradio for recording 4
channels to disk from a USRP?
Thanks, - Tom
From: Josh Blum
To: Tom Hendrick
Cc: "di
you, -Tom
From: Josh Blum
To: Tom Hendrick
Cc: "discuss-gnuradio@gnu.org"
Sent: Sunday, March 10, 2013 10:29 PM
Subject: Re: [Discuss-gnuradio] LibUSRP vs LibUHD Performance on older machines
On 03/08/2013 02:44 PM, Tom Hendrick wrote:
> Hi Josh,
>
> Would y
.
Thanks, -Tom
From: Josh Blum
To: Tom Hendrick
Cc: "discuss-gnuradio@gnu.org"
Sent: Sunday, March 10, 2013 10:29 PM
Subject: Re: [Discuss-gnuradio] LibUSRP vs LibUHD Performance on older machines
On 03/08/2013 02:44 PM, Tom Hendrick wrote:
> Hi Jo
h
To: Tom Hendrick ; "Discuss-gnuradio@gnu.org"
Sent: Monday, March 11, 2013 8:29 AM
Subject: Re: [Discuss-gnuradio] LibUSRP vs LibUHD Performance on older machines
On 03/11/2013 02:00 AM, Tom Hendrick wrote:
Hello Josh, Thanks for responding.
>I just tried your suggestion.
>
Hello,
I'm interested in editing some of the source and sink .cc files.
On my older laptop I have obtained GNURadio from the terminal using the build
instructions. I am able to locate the .cc files I am interested in editing.
On my newer laptop I installed GNURadio and GRC using the synaptic p
Hi
I am using a web
camera to get an MPEG-4 rtsp stream that is set to a constant bitrate. I
have a script which pipes the rtsp stream to a code in C++. The C++
code modulates the signal and writes a .WAV file to the hard disk.
I have a python script which interfaces with GNURadio/USRP
adio] Piping to the USRP - mkfifo issue
To: "Tom Hendrick"
Cc: discuss-gnuradio@gnu.org
Date: Monday, March 7, 2011, 12:53 AM
On Sun, Mar 6, 2011 at 6:59 PM, Tom Hendrick wrote:
Hi
I am using a web
camera to get an MPEG-4 rtsp stream that is set to a constant bitrate. I
have a sc
Hello All
I have a basic/beginner question.
I am using mkfifo to pipe output from a C++ application to a GRC script using a
named pipe.
I'm using C++ code that another student wrote and I am not too keen on making
difficult changes to it. In mode 1, it outputs a waveform in double values in
Hi all,
I'm having some issues with the USRP and some latency in the output signal. I
am using a C++ program which modulates a signal and writes to a file
continuously.
When I use a normal file, the C++ program output looks perfect. When I use a
script made in GRC to read the C++ output file
Josh..
Thanks, real time scheduling is enabled, and I run my python script with sudo
and I do not see the typical failure message saying real-time was not enabled.
When I run the C++ program in one terminal and output the modulated signal to a
normal file, I can read that file in with my python
Hi all.
I am still trying to figure out how to deal with doubles in GRC. Has anyone
tried to make a block that converts from double to float? I recall Josh
suggesting to make this block from another post I made, but I am a beginner
with python/GRC and cannot figure out how to make it myself
Hi all,
I'm using a C++ program that modulates a signal that I feed to GRC via an
mkfifo (named pipe) file. The problem is that I get underruns from the USRP.
There is a function in the C++ program that converts from double to float and
then dumps it to stdout which I then feed to an mkfifo
aun wrote:
From: Martin Braun
Subject: Re: [Discuss-gnuradio] Buffer Question for Streaming with USRP
To: discuss-gnuradio@gnu.org
Date: Monday, April 4, 2011, 8:10 AM
On Sun, Apr 03, 2011 at 07:12:58PM -0700, Tom Hendrick wrote:
> Hi all,
>
> I'm using a C++ program that modul
Hello all.
I am slowly making progress on a streaming application but am coming across
some problems with underruns on the transmit side.
I am using a C++ program to modulate an input signal. Unfortunately the input
signal to the C++ has a variable bitrate. The problem is that the C++ progra
Hello all, I am helping a colleague with the USRP center frequency tuning
functionality and it is my understanding the signal must contain I and Q values
centered at 0Hz.
A real valued signal is generated independently by another program and is fed
to a GRC script. Is it easy/possible to make
h one in GRC)
Thank you again! - Tom
--- On Tue, 6/21/11, Marcus D. Leech wrote:
From: Marcus D. Leech
Subject: Re: [Discuss-gnuradio] Real Signal to I/Q Samples
To: discuss-gnuradio@gnu.org
Date: Tuesday, June 21, 2011, 11:56 PM
On 06/21/2011 05:33 PM, Tom Hendrick
I have a really simple question that I can't seem to find the answer to online
(and pardon my limited signal processing background). I'm trying to help a
fellow colleague figure out a processing problem.
An external code modulates a real-valued signal that is eventually fed into
GRC. For now t
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