Re: [Discuss-gnuradio] Getting the API version at compile time
The approach that I used is similar, but I thought I'd mention it because it only relies on the installation and not on having the source code (I'm using a Ubuntu package). The newer version supports the UHD drivers and there is an install directory for the headers, so I added the following to my makefile: USRP_API_VERSION=$(shell if test -d /usr/local/include/uhd ; then echo NEW_USRP_API ; else echo OLD_USRP_API ; fi ;) I used the USRP_API_VERSION variable in a "-D" compiler option. Thanks for the suggestions, which led to the solution I adopted. Johnathan Corgan-2 wrote: > > On Oct 12, 2011, at 20:13, Tom Rondeau wrote: > > On Wed, Oct 12, 2011 at 5:26 AM, Peter D. Massam > wrote: > >> I need to be able to maintain my program for both old and new systems >> and >> I've been looking for a version constant that I can use for conditional >> compilation. >> >> ** >> > You can find the version information in > $(top_builddir)/gnuradio-core/gnuradio-core.pc. This is... > > ___ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > -- View this message in context: http://old.nabble.com/Getting-the-API-version-at-compile-time-tp32637243p32644037.html Sent from the GnuRadio mailing list archive at Nabble.com. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] DAC I/Q swap and bit inversion
On Wed, Oct 12, 2011 at 4:12 PM, Ian Buckley wrote: > (Matt, this just occurred to me, you should be 2's comping the bus here, > not simply inverting it, you've introduced an LSB DC offset). An optimization -- the 1 LSB offset is swamped by real offset in the hardware, so we just take it out as part of normal DC offset calibration. Matt ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Signal Seperation
Hi, Could somebody give me some tips and help on the following problem? Really appreciated! The input signal is b1(t)*sin(f1*t) + b2(t)*sin(f2*t), where f1 and f2 are close but different, and b1(t) and b2(t) are two different square waves with different period. After the USRP down coverts this wave to the baseband, the two modulated sine waves are mixed. How could I extract b2(t) or b1(t) respectively? I tried to used a baseband filter, but it seems not work well. Thanks! -- -- Best Regards (Raullen) Qi Chai ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] GRC Polyphase Channelizer examples?
Is there a (hopefully simple) example of using the polyphase channelizer block in grc? I'm trying to do a simple case of dividing a 250 kHz wide stream from USRP into a small number (initially 4) of contiguous channels. Given my generally ignorant status, I'm stumped on setting the parameters. e.g. -- (a) is the "taps" param an integer or is it a firdes function as in the xlating FIR filter? (b) what is the oversample param used for? (c) what is the sample rate of each of the output channels -- it doesn't appear to be the same at the sample rate at the input, or alternatively my parameters are so far off that what's coming out of the thing is absolute junk (when I feed it into a USRP sink set to 250ksamples, I get screens of underruns). Thanks, John ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] GRC Polyphase Channelizer examples?
On 10/13/2011 09:11 PM, John Ackermann N8UR wrote: Is there a (hopefully simple) example of using the polyphase channelizer block in grc? I'm trying to do a simple case of dividing a 250 kHz wide stream from USRP into a small number (initially 4) of contiguous channels. Given my generally ignorant status, I'm stumped on setting the parameters. e.g. -- (a) is the "taps" param an integer or is it a firdes function as in the xlating FIR filter? (b) what is the oversample param used for? (c) what is the sample rate of each of the output channels -- it doesn't appear to be the same at the sample rate at the input, or alternatively my parameters are so far off that what's coming out of the thing is absolute junk (when I feed it into a USRP sink set to 250ksamples, I get screens of underruns). Thanks, John If it's only 250Khz wide, and you only need four, have you tried 4 discrete freq-xlating FIR filters? They're fairly easy to use, and can produce a baseband output at a decimated rate. I haven't yet figured out how to use the polyphase channelizer because I almost never have the N equi-spaced channels problem in my fields of interest. So, discrete filters it is (sometimes a hierarchy of discrete filters). -- Marcus Leech Principal Investigator Shirleys Bay Radio Astronomy Consortium http://www.sbrac.org ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] New webpage look
i think josh is right about the color. Instead of red, some shade of blue or green might give a better look. http://gnuradio.org/redmine/projects/gnuradio/wiki instead of putting "Start page", "Index by Title", "Index by Date" buttons on right-side, they may be placed on the top of start page (maybe beside "History"). This may be useful for people new to gnuradio website (initially for 2 weeks, i thought that "start page" is the only wiki) ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] gr_file_sink error handling and incorrect behavior on broken pipes
This relates to a previous post regarding the behavior of gr_file_sink
when it writes to a named pipe and the other side of the pipe stops reading.
Currently the bahavior of the block is that it does not catch the
"errno=32=EPIPE"
(or any errno!=0 for that matter)
and thus the work function returns a false number of consumed items
(for some reason even with a broken pipe it always returns 512 items
consumed...)
As a result the remaing graph keeps producing samples that are somehow falsely
consumed into the file sink.
I added a couple of lines to check for the errno!=0
Please check and comment.
I attach 2 python files to check the bahavior of the file sink.
Firtst do " mkfifo fifo_rx" and then run tx.py and rx.py in different shells.
You can stop start rx.py any number of times and tx.py pauses and
restarts as well.
Observe though that tx.py consumes cpu even when the pipe is broken
because it continuosly calls
the gr_file_sink work function...
Achilleas
==
diff --git a/gnuradio-core/src/lib/io/gr_file_sink.cc
b/gnuradio-core/src/lib/io/gr_file_sink.cc
index aab0158..52d4c84 100644
--- a/gnuradio-core/src/lib/io/gr_file_sink.cc
+++ b/gnuradio-core/src/lib/io/gr_file_sink.cc
@@ -27,6 +27,8 @@
#include
#include
#include
+#include
+#include
gr_file_sink_sptr
@@ -64,9 +66,16 @@ gr_file_sink::work (int noutput_items,
return noutput_items; // drop output on the floor
while (nwritten < noutput_items){
+errno=0;
int count = fwrite (inbuf, d_itemsize, noutput_items - nwritten, d_fp);
-if (count == 0)// FIXME add error handling
+if (count == EOF){ // FIXME add error handling
+ //printf("fwrite() returned EOF. Requested %d and wrote
%d\n",noutput_items - nwritten,count);
break;
+}
+if (errno!=0){ // FIXME add error handling
+ //printf("fwrite() raised error no = %d. Requested %d and wrote
%d\n",errno,noutput_items - nwritten,count);
+ break;
+}
nwritten += count;
inbuf += count * d_itemsize;
}
diff --git a/gnuradio-core/src/lib/io/gr_file_sink.cc
b/gnuradio-core/src/lib/io/gr_file_sink.cc
index aab0158..52d4c84 100644
--- a/gnuradio-core/src/lib/io/gr_file_sink.cc
+++ b/gnuradio-core/src/lib/io/gr_file_sink.cc
@@ -27,6 +27,8 @@
#include
#include
#include
+#include
+#include
gr_file_sink_sptr
@@ -64,9 +66,16 @@ gr_file_sink::work (int noutput_items,
return noutput_items; // drop output on the floor
while (nwritten < noutput_items){
+errno=0;
int count = fwrite (inbuf, d_itemsize, noutput_items - nwritten, d_fp);
-if (count == 0)// FIXME add error handling
+if (count == EOF){ // FIXME add error handling
+ //printf("fwrite() returned EOF. Requested %d and wrote
%d\n",noutput_items - nwritten,count);
break;
+}
+if (errno!=0){ // FIXME add error handling
+ //printf("fwrite() raised error no = %d. Requested %d and wrote
%d\n",errno,noutput_items - nwritten,count);
+ break;
+}
nwritten += count;
inbuf += count * d_itemsize;
}
#!/usr/bin/env python
##
# Gnuradio Python Flow Graph
# Title: Tx
# Generated: Thu Oct 13 23:55:47 2011
##
from gnuradio import eng_notation
from gnuradio import gr
from gnuradio import window
from gnuradio.eng_option import eng_option
from gnuradio.gr import firdes
from gnuradio.wxgui import fftsink2
from grc_gnuradio import wxgui as grc_wxgui
from optparse import OptionParser
import wx
class tx(grc_wxgui.top_block_gui):
def __init__(self):
grc_wxgui.top_block_gui.__init__(self, title="Tx")
##
# Variables
##
self.samp_rate = samp_rate = 100e3
##
# Blocks
##
self.wxgui_fftsink2_0 = fftsink2.fft_sink_c(
self.GetWin(),
baseband_freq=0,
y_per_div=10,
y_divs=5,
ref_level=20,
ref_scale=2.0,
sample_rate=samp_rate,
fft_size=1024,
fft_rate=30,
average=True,
avg_alpha=0.1,
title="FFT Plot",
peak_hold=False,
)
self.Add(self.wxgui_fftsink2_0.win)
self.gr_sig_source_x_0 = gr.sig_source_c(samp_rate, gr.GR_COS_WAVE, 5000, 1, 0)
self.gr_noise_source_x_0 = gr.noise_source_c(gr.GR_GAUSSIAN, 0.1, 42)
self.gr_file_sink_0 = gr.file_sink(gr.sizeof_gr_complex*1, "fifo_rx")
self.gr_file_sink_0.set_unbuffered(True)
self.gr_add_xx_0 = gr.add_vcc(1)
##
# Connections
##
self.connect((self.gr_noise_source_x_0, 0), (self.gr_add_xx_0, 1))
self.connect((self.gr_sig_source_x_0, 0), (self.gr_add_xx_0, 0))
self.connect((self.gr_add_xx_0, 0), (self.wxgui_fftsink2_0, 0))
self.connect((self.gr_add_xx_0, 0), (self.gr_file_sink_0, 0))
def get_sa
