Re: [Discuss-gnuradio] About Top_block

[Mir M. Ali]

Hi,

The simplest examples that you can look at to understand about gnuradio can
be found at this website.
http://www.joshknows.com/gnuradio

Think of gnuradio as a system of blocks that perform unique functions. Each
of these blocks will either behave as a sink or a source. Your job is to
find which of these blocks do the work for you. Once you identify these
blocks you must connect them to so as to make the output of one block be the
input of the next hierarchical block.

We no longer use hier_block. If you look at the new examples its called
top_block. It's the same thing but with a new name. hier_block or top_block
means the overall system that you are building which makes use of other
blocks inside of it.

As a beginner you need not understand how the connect and run do things for
you. When you call "connect" think of it as telling a block to pass its
output to the next block in hierarchy as its input. And calling "run" as
telling your implemented system to start doing its work. Just assume that
whatever they do is perfectly done and all you need to worry about is how
can you implement your system with the blocks that you already have in
gnuradio or you may implement your own blocks in C++. To learn how to make
blocks look at the tutorial in your gnuradio installation. Its found in
"gnuradio/gr-howto-write-a-block" directory.

Take a look at the examples in /usr/local/share/gnuradio/examples directory.
I started with examples in "audio" directory and "digital" directory.
Understanding of benchmark_tx and benchmark_rx in digital directory
according to me is of prime importance.

I say it again. Don't worry about how python knows about connect and run.
Trying to know this will take you a lot of time. Begin with understanding
what Gnuradio actually accomplishes. Once, you get the feel of this you can
spend time understanding how the scheduler and other intricate stuff works.


Take a look at documentation about USRP. Understanding of things that happen
in a usrp is essential too.
http://rapidshare.com/files/121692530/USRP_Documentation.pdf

This is what I did as a beginnner and it took me a lot of time to understand
gnuradio. Even though I don't understand it as good as others on this list
do but still I am comfortable working with it. Even to this date I didn't
spend time on understanding how run/connect work as I never felt it was
necessary to do so. I believe in "Why reinvent the wheel?" philosophy and I
am happy with it.

Good Luck
Ali


On Tue, Jun 16, 2009 at 4:51 AM, Chun-Ta Kung  wrote:

> Hello,
> I am new to gnuradio, and I felt confused with "glue the blocks", such as
> hier_block2.
> I have read gnu tutorial by Mr. Shen and I understood there were multiple
> attributes to describe a block, such as endpoint and edge.
> But when I tried to analyze an example of code, there was no such block of
> code to elaborate on
> them. I cannot understand how python knows how to connect between two
> blocks.
> Which signal plays as input or output to connect between them? And am I
> able to use only line-by-line code to replace partial usage of glue(
> top_block.connect(block1,block2)) ?
>
> p.s I thought this should be  a preliminary question. There must be
> something seriously wrong with my concept. Please correct it if you don't
> mind spending some time typing.
>
> Thank you all
>
>
>
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[Discuss-gnuradio] Re: xcvr2450, v3.2 and usrp1

[William Sherman]

Here is my console output for a transmit program:
The XCVR2450 doesn't transmit.

python rx2_pu_tx.py -f 2.4G
xcvr2450: Setting reg 2 to 30072
xcvr2450: Setting reg 5 to 38225
xcvr2450: Setting reg 5 to 38A25
xcvr2450: Setting reg 6 to 4006
xcvr2450: Setting reg 7 to 627
xcvr2450: Setting reg 8 to 1C218
xcvr2450: Setting reg 9 to 68B9
xcvr2450: Setting reg 10 to 3C0A
xcvr2450: Setting reg 11 to 10B
xcvr2450: Setting reg 12 to 3FC
xcvr2450: Setting reg 3 to 963
xcvr2450: Setting reg 4 to 4
xcvr2450: Setting reg 5 to 38225
xcvr2450: Setting reg 5 to 38A25

tx tune result:
baseband freq: 24.00
dxc freq: -0.00
residual freq: -0.00
>>> gr_fir_ccf: using SSE
xcvr2450: Setting reg 12 to 3FC
modulation:  dbpsk
Channel freq:2.4G
RX/TX bitrate:   250kb/sec
samples/symbol:2
TX interp:256
original_payload = 01:01:01
uUuUuU^Z
Suspended
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Re: [Discuss-gnuradio] Using the USRP2 external SRAM

[Tiago Rogério Mück]

Thanks for the answer.

I'm going to start working on it soon and then I'll come back here with the
results (or with the problems :)

2009/6/15 Eric Blossom 

> On Wed, Jun 10, 2009 at 04:59:24PM -0300, Tiago Rogério Mück wrote:
> > Hi all,
> >
> > I'm working on some experiments using the USRP2, and the 32 Kb available
> for
> > the firmware won't be enough for my experiments. I'll need to modify the
> > FPGA code so I can use the 1 MB SRAM for both instructions and data for
> the
> > aeMB, but I'm a bit lost on how I can do this modifications.
> >
> > I looked the code and came to some conclusions about what needs to be
> done:
> >
> > 1 - Change the memory map
> >  - Change the RAM space to 0 - 1 MB
> >  - Update the mapping of the buffer poll and the peripherals
> >
> > 2 - Change the logic inside the sys_ram block to forward access to
> addresses
> > beyond 32 K to the external SRAM
> >
> > 3 - Change the ram_loader parameters so it can load the entire firmware.
> >
> > Could someone tell me if I'm going to the right direction? I will be very
> > grateful for any hint you can give me.
>
> Yes, this is the right direction.  You'll probably want to include a
> dcache to get any kind of throughput out of it.  There's currently a
> small icache.
>
> Eric
>
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Re: [Discuss-gnuradio] USRP question: Writing to AD9862 registers from FPGA?

[Eric Blossom]

On Wed, Jun 03, 2009 at 10:28:55PM -0400, Aviv Keshet wrote:
> Hi gnuradiators,
> 
> I know I can use the usrper program to write values to the registers of the 
> two
> 9862 chips (on the USRP1). I am using the USRP1 for a custom application, with
> my own FPGA code. My question is whether it is possible for the FPGA to write
> values to these registers directly?

No, there are no wires that connect these.

> Or is it only the cypress microcontroller that has access to these registers?

yes.

> And if so, is it possible for the FPGA to command the microcontroller to do 
> so?

no.


> I didn't find any obvious verilog module that does this when looking through 
> the
> original verilog code. If it exists and I missed it, please let me know.
> 
> Thank you,
>Aviv Keshet

FYI, on the USRP2 everything connects to the FPGA ;-)

Eric


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Re: [Discuss-gnuradio] Driver for USRP1

[Steve Totaro]

G4U (Ghost for Unix) is exactly what you need.

It is a BSD based boot disc.

On Tue, Jun 16, 2009 at 12:58 PM, Frank Rawlins wrote:
>
> I wonder if anyone can help.  I use USRP1 mainly for RA with UBUNTU
> 9.04, what I would like is a program to create an image of the whole hard
> drive on a DVD.  Therefore, if the PC or hard drive fails I can run the DVD
> on the same or different computer installing all associations automatically
> to drive the USRP.    Keeping UBUNTU at 9.04 forever and all associations
> would not be a problem for me as long as everthing is stored on DVDs.
> Anyone know of such a program?
>
> Thanks,
>
> Frank Rawlins
> England
>
>
> 
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Re: [Discuss-gnuradio] Problem with playback

[Pascal Charest]

On Mon, Jun 15, 2009 at 6:53 PM, hjaffer  wrote:

> But there is no program that reads a file and transmits the data in the
> file.


I've made available online a python script that does that. You can download
it at . It takes raw samples as
input. The output can be a mix of the gnuradio oscilloscope (-o), the
gnuradio spectrum (-s) or the USRP (-u).

I hope it will answer your needs. If not, at least you will have some code
to start playing with. Please note that GUI does not work except for the
close button...

Pascal
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Re: [Discuss-gnuradio] Driver for USRP1

[Pascal Charest]

On Tue, Jun 16, 2009 at 3:27 PM, Frank Rawlins wrote:

>  Thank you for your reply John.  However, I think you might have thought I
> meant copying data.
>
> In a typical setup with a complete clean hardrive (nothing installed) I
> would first install the operating system, in this case UBUNTU 9.04.  I then
> go the appropriate site to copy all the links and associated programs for
> USRP to work this can take up to 1 hour usually with problems.  Once
> everything is running well I want to copy the total image of this hard drive
> on to a DVD.  The DVD can then be used to install the operating system plus
> all associations on another clean hardrive.  Therefore,  being
> completely independent of the internet to install USRP on a new PC.
>

Try remastersys


I never used it, but it seems to do the job.

Pascal
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Re: [Discuss-gnuradio] Re: GNU radio and cygwin

[Eric Blossom]

On Wed, Jun 10, 2009 at 02:58:32PM +0530, Ravishankar. M wrote:
> Hello all,
> 
>   I hereby forward the mail again with an anticipation to get a reply.
> 
>   I am new to gnu radio and cygwin. I have installed GNU radio with cygwin.
> As is the case python scripts act as wrapper for underlying C++ source. When
> trying to run scripts from cygwin, is there a way to debug the code by
> putting breakpoints? There's an intention to analyze the inputs and outputs
> of signal processing blocks and hence need to debug using breakpoints.
> Thanks in advance.
> 
> Regards
> Ravi 

Ravi,

We generally analyze the inputs and outputs of signal processing
blocks by logging their inputs and outputs to files using
gr.file_sink(...).  This allows us to quickly gather lots of data
which is then typically viewed using tools such as octave, scipy and
matplotlib.

Eric


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RE: [Discuss-gnuradio] Driver for USRP1

[Frank Rawlins]

Thank you for your reply John.  However, I think you might have thought I meant 
copying data.

 

In a typical setup with a complete clean hardrive (nothing installed) I would 
first install the operating system, in this case UBUNTU 9.04.  I then go the 
appropriate site to copy all the links and associated programs for USRP to work 
this can take up to 1 hour usually with problems.  Once everything is running 
well I want to copy the total image of this hard drive on to a DVD.  The DVD 
can then be used to install the operating system plus all associations on 
another clean hardrive.  Therefore,  being completely independent of the 
internet to install USRP on a new PC.

 

Hope this makes sense.

 

Frank


 
> To: f.anth...@hotmail.co.uk; g...@toad.com
> Subject: Re: [Discuss-gnuradio] Driver for USRP1 
> Date: Tue, 16 Jun 2009 10:47:53 -0700
> From: g...@toad.com
> 
> A DVD would not be a good replacement for a hard drive -- particularly
> because it isn't writeable (and many things expect to write to the file
> system, even for small log files and such).
> 
> It would be easier to install Ubuntu onto a USB memory stick, boot it,
> and copy over whatever changes you need for your RA USRP setup. Then
> you can just make copies of this USB stick as needed to run it in
> various places. 
> 
> You can get these sticks in various sizes, smaller or larger than a DVD,
> for two to thirty dollars each.
> 
> John

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Re: [Discuss-gnuradio] USRP1 DBSRX 10MHz reference clock

[Eric Blossom]

On Tue, Jun 16, 2009 at 11:24:31AM -0700, Kutik wrote:
> 
> Eric Blossom wrote:
> > 
> > On Tue, Jun 16, 2009 at 08:23:37AM -0700, Kutik wrote:
> >> 
> >> I would like to change the USRP master clock to 10MHz.
> >> 
> >> I call urx->set_fpga_master_clock_freq(10e6) prior to
> >> usrp_standard_rx::make.
> >> 
> >> I wonder how to set the REFCLK_DIVISOR in db_dbs_rx::_refclk_divisor().
> >> 
> >> From all examples I have seen the (master_clock/REFCLK_DIVISOR) is 4MHz.
> >> This would mean REFCLK_DIVISOR must be 2.5, but on the other hand it must
> >> be
> >> an integer..
> >> 
> >> Can I set the REFCLK_DIVISOR to 3 (resulting in Max2118 clock 3.33MHz)?
> >> Or
> >> would you recommend something else?
> > 
> > Can you tell us what you are really trying to do?  Why do you want to
> > change the master clock to 10MHz?  The USRP won't function with that
> > slow of a clock.  It won't be able to talk over the GPIF port to the
> > FX2 USB controller.
> > 
> > Eric
> > 
> 
> 
> Thanks for the answer,
> 
> I would like to acquire narrowband data (200 kHz). In this range I'll
> receive multiple CW signals. The maximal frequency inaccuracy is 2kHz.
> Therefore USRP1 has to be disciplined by precise reference clock.
> 
> I have 10MHz reference signal available, and hoped there will be no need to
> buy 64MHz oscillator (disciplined by 10MHz).
> 
> I've read (usrp_basic.h) the master clock range is 10-64MHz, thus I wanted
> to give it a try.

OK, thanks.

After some off-list discussion, I think you should be able to make
this work.  I expect that Johnathan or Matt will chime in with some
additional information.  (The GPIF bus uses a clock from the FX2, so I
was mistaken about that being a problem.)

Eric


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Re: [Discuss-gnuradio] USRP1 DBSRX 10MHz reference clock

[Kutik]

Eric Blossom wrote:
> 
> On Tue, Jun 16, 2009 at 08:23:37AM -0700, Kutik wrote:
>> 
>> I would like to change the USRP master clock to 10MHz.
>> 
>> I call urx->set_fpga_master_clock_freq(10e6) prior to
>> usrp_standard_rx::make.
>> 
>> I wonder how to set the REFCLK_DIVISOR in db_dbs_rx::_refclk_divisor().
>> 
>> From all examples I have seen the (master_clock/REFCLK_DIVISOR) is 4MHz.
>> This would mean REFCLK_DIVISOR must be 2.5, but on the other hand it must
>> be
>> an integer..
>> 
>> Can I set the REFCLK_DIVISOR to 3 (resulting in Max2118 clock 3.33MHz)?
>> Or
>> would you recommend something else?
> 
> Can you tell us what you are really trying to do?  Why do you want to
> change the master clock to 10MHz?  The USRP won't function with that
> slow of a clock.  It won't be able to talk over the GPIF port to the
> FX2 USB controller.
> 
> Eric
> 


Thanks for the answer,

I would like to acquire narrowband data (200 kHz). In this range I'll
receive multiple CW signals. The maximal frequency inaccuracy is 2kHz.
Therefore USRP1 has to be disciplined by precise reference clock.

I have 10MHz reference signal available, and hoped there will be no need to
buy 64MHz oscillator (disciplined by 10MHz).

I've read (usrp_basic.h) the master clock range is 10-64MHz, thus I wanted
to give it a try.
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Re: [Discuss-gnuradio] USRP1 DBSRX 10MHz reference clock

[Eric Blossom]

On Tue, Jun 16, 2009 at 08:23:37AM -0700, Kutik wrote:
> 
> I would like to change the USRP master clock to 10MHz.
> 
> I call urx->set_fpga_master_clock_freq(10e6) prior to
> usrp_standard_rx::make.
> 
> I wonder how to set the REFCLK_DIVISOR in db_dbs_rx::_refclk_divisor().
> 
> From all examples I have seen the (master_clock/REFCLK_DIVISOR) is 4MHz.
> This would mean REFCLK_DIVISOR must be 2.5, but on the other hand it must be
> an integer..
> 
> Can I set the REFCLK_DIVISOR to 3 (resulting in Max2118 clock 3.33MHz)? Or
> would you recommend something else?

Can you tell us what you are really trying to do?  Why do you want to
change the master clock to 10MHz?  The USRP won't function with that
slow of a clock.  It won't be able to talk over the GPIF port to the
FX2 USB controller.

Eric


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Re: [Discuss-gnuradio] Quesion on AUX ADC of AD9862

[Eric Blossom]

On Tue, Jun 16, 2009 at 09:15:34PM +0800, Su Jinzhao wrote:
> Hi,
> 
> I want to read RSSI value using analog AUX ADC, I think we can read RSSI
> through AUX_ADC_A1 pin of AD9862, I looked through the code
> of usrp_read_aux_adc in file
> /root/gnuradio/gnuradio-3.1.3/usrp/host/lib/legacy/usrp_primes.cc,

If you are using usrp_standard_rx, or gr.usrp_source_*, you can do
this much more simply by using:

  adc_val = u->read_aux_adc(which_side, which_adc)

http://gnuradio.org/doc/doxygen/classusrp__basic__rx.html
http://gnuradio.org/doc/doxygen/classusrp__standard__rx.html

You didn't mention which daughterboard you are using.  Not all
daughterboards have an analog RSSI output.

> my question is:
> 1.The AD 9862 specification says: "The AUX SPI can be enabled and configured
> by setting register AUX ADC CTRL. Setting register use pins high enables the
> AUX SPI port.", but in the above code AUX_ADC_CTRL_AUX_SPI was not set high(
> In my opinion, aux_adc_control should be added with | = AUX_ADC_CTRL_AUX_SPI
> because usrp_9862_write and usrp_9862_read all need SPI operation, so we
> should enable AUX API), Is this a mistype or another method ?

The code is correct.  There are a couple of ways to use the AUX ADCs.
We use them by polling, not over the AUX SPI bus.

> 2.stefan.bruens in the list had said that the low 16 bits is the RSSI value,
> I want to know why did the above code combine the high and low 16-bit and
> format the data into 12-bit ?

This is a digital RSSI, determined post high-speed ADC.  You can look
at the computation here:

  http://gnuradio.org/trac/browser/gnuradio/trunk/usrp/fpga/sdr_lib/rssi.v
  

> 3. Even with the RSSI value (int type), what should I do to convert that
> value into dBm unit ?

You would need to calibrate the entire signal path.  Left as an exercise...

Eric


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[Discuss-gnuradio] Driver for USRP1

[Frank Rawlins]

 
I wonder if anyone can help.  I use USRP1 mainly for RA with UBUNTU 9.04, what 
I would like is a program to create an image of the whole hard drive on a DVD.  
Therefore, if the PC or hard drive fails I can run the DVD on the same or 
different computer installing all associations automatically to drive the USRP. 
   Keeping UBUNTU at 9.04 forever and all associations would not be a problem 
for me as long as everthing is stored on DVDs.  Anyone know of such a program? 
 
Thanks,
 
Frank Rawlins

England


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Re: [Discuss-gnuradio] parallel data reception

[Josh Blum]

There is a handy dual_usrp wrapper in grc:
http://gnuradio.org/trac/browser/gnuradio/trunk/grc/src/grc_gnuradio/usrp/dual_usrp.py

You can use it like:
from grc_gnuradio import usrp as grc_usrp
grc_usrp.dual_source_c(..)

Or use the code as an example

-Josh

kaleem ahmad wrote:

Hallo,

We use following when there is only one RFX2400 daughter card (I think there
is onle one subdev in RFX2400 cardIs it correct???).

u = usrp_source()

u.set_mux(usrp.determine_rx_mux_value(u, rx_subdev_spec))


Can some one guide me how do I change it when two RFX2400 daughtercards are
used.

And what additional processing needs to be done to separate data streams
from RX2 antennas of both 
cards.


Best Regards




Jason Uher wrote:

I am using USRP1 + RFX2400.

You know there are two antenna ports on RFX2400 daughter card those are
RX2,
TX/RX. Is it possible to use both these ports in parallel for data
reception. If yes then pelase provide me little clue how I should do it,
or
may be refer me to some existing example.

I have two RFX2400 daughter cards and my problem is to use two different
ports for data reception, it doesnt matter if I use two ports on a single
card (i.e RX2, and RX/TX), or two ports on two different cards (e.g. RX2
on
each card). Please let me know which one is possible and easier to
implement
and please also refer me to some application where I can find relevant
code.


I do not believe it is possible to receive data from the TX/RX and TX
port simultaneously, I believe the are tied to the same set of ADCs.
You should use two RFX cards if you are planning on doing MIMO
reception.  Check in the examples section, I don't think there is a
specific 2 antenna receive example with the 2400's; but there is a 4rx
fm receiver that you should be able to extrapolate from.

Jason


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Re: [Discuss-gnuradio] parallel data reception

[kaleem ahmad]

Hallo,

We use following when there is only one RFX2400 daughter card (I think there
is onle one subdev in RFX2400 cardIs it correct???).

u = usrp_source()

u.set_mux(usrp.determine_rx_mux_value(u, rx_subdev_spec))


Can some one guide me how do I change it when two RFX2400 daughtercards are
used.

And what additional processing needs to be done to separate data streams
from RX2 antennas of both 
cards.

Best Regards




Jason Uher wrote:
> 
>> I am using USRP1 + RFX2400.
>>
>> You know there are two antenna ports on RFX2400 daughter card those are
>> RX2,
>> TX/RX. Is it possible to use both these ports in parallel for data
>> reception. If yes then pelase provide me little clue how I should do it,
>> or
>> may be refer me to some existing example.
>>
>> I have two RFX2400 daughter cards and my problem is to use two different
>> ports for data reception, it doesnt matter if I use two ports on a single
>> card (i.e RX2, and RX/TX), or two ports on two different cards (e.g. RX2
>> on
>> each card). Please let me know which one is possible and easier to
>> implement
>> and please also refer me to some application where I can find relevant
>> code.
>>
> 
> I do not believe it is possible to receive data from the TX/RX and TX
> port simultaneously, I believe the are tied to the same set of ADCs.
> You should use two RFX cards if you are planning on doing MIMO
> reception.  Check in the examples section, I don't think there is a
> specific 2 antenna receive example with the 2400's; but there is a 4rx
> fm receiver that you should be able to extrapolate from.
> 
> Jason
> 
> 
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[Discuss-gnuradio] USRP1 DBSRX 10MHz reference clock

[Kutik]

I would like to change the USRP master clock to 10MHz.

I call urx->set_fpga_master_clock_freq(10e6) prior to
usrp_standard_rx::make.

I wonder how to set the REFCLK_DIVISOR in db_dbs_rx::_refclk_divisor().

>From all examples I have seen the (master_clock/REFCLK_DIVISOR) is 4MHz.
This would mean REFCLK_DIVISOR must be 2.5, but on the other hand it must be
an integer..

Can I set the REFCLK_DIVISOR to 3 (resulting in Max2118 clock 3.33MHz)? Or
would you recommend something else?
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Re: [Discuss-gnuradio] High packet error and reception problems with XCVR 2450

[Johnathan Corgan]

On Tue, Jun 16, 2009 at 7:31 AM, udadidd wrote:

> 3) benchmark_tx/rx do not receive any packets though i give a transmit
> amplitude of 3 and rx-gain of 75. The transmission seems to be sending
> 666 packets where as i receive only total of around 60 packets on the
> receiver end with ok=FALSE Always!! I get a 100% error rate.

Not commenting on the rest, but with respect to power and gain settings:

More transmit power is not always better.  More receiver gain is not
always better.  The above settings are almost guaranteed to fail.

You should use usrp_fft.py on the receiver side and leave it at
mid-gain.  Then use benchmark_tx.py and increase or decrease the
transmit amplitude, while monitoring the receive spectrum, until you
get the widest separation between the noise floor and the modulated
signal spectrum.  In general, the RFX2400 and other RFX boards start
to go into gain compression at a transmit amplitude of about 10-15%
DAC full-scale, which with the USRP1, is about 3000-5000.  Beyond
this, transmitting non-constant envelope signals will result in
significant distortion.  For a bench top transmission channel, the
RFX2400 can generate far more power than is needed to get essentially
error-free reception.

Once you have a transmit power that corresponds to the "best looking"
spectrum in usrp_fft.py on the receiver, you can then adjust the
receiver gain to further improve the signal-to-noise ratio.  Too low a
gain doesn't amplify the signal enough, so you see it drop into the
noise floor.  Too high a gain starts to increase the noise floor
without further increasing the signal level, due to non-linearities in
the receiver causing distortion.  So again, there will be a "just
right" spot.  At this point, you may be able to go back to the
transmitter and further improve things now that the receiver is
operating with the better gain setting.

Once you have a good pair of transmit amplitude and receiver gain for
your particular setup, then you can start running the benchmark_rx.py
script with the same gain setting to start receiving the packets being
sent by the transmitter.

Johnathan


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[Discuss-gnuradio] High packet error and reception problems with XCVR 2450

[udadidd]

Hi
We bought 2 USRP boards very recently and it doesn't seem to work. We have
daughter boards XCVR 2450 and vertical antennas (Black colored) VERT2450. We
also have TVRX daughter board which works properly.

We had been trying usrp_siggen.py, usrp_oscope.py on each of these. Also
digital/benchmark_tx.py and benchmark_rx.py on both of these. 

1) usrp_oscope.py doesn't give me a proper sine wave at all!

2) usrp_siggen.py or even usrp_fft.py doesnt seem to give me satisfactory
results. (I am comparing the results according to the screen shots i saw in
the web page http://staff.washington.edu/jon/gr-osx/gr-osx-usrp.html#using)

3) benchmark_tx/rx do not receive any packets though i give a transmit
amplitude of 3 and rx-gain of 75. The transmission seems to be sending
666 packets where as i receive only total of around 60 packets on the
receiver end with ok=FALSE Always!! I get a 100% error rate.

Do you think there are any problems with the daughterboards? or the
combination of daughter board with the antennas? Kindly let me know how do i
check the functioning of the daughter boards and/or the antennas!

Kindly help
Udaya



Syed Faisal Shah wrote:
> 
> Matt,
> 
> Thanks for clarifying the matter. My colleague discussed it with you and
> we
> look forward to receive the correct antennas.
> 
> Regards
> 
> -Faisal
> 
> 
>  Just to clarify for everyone, since I get a LOT of calls about this...
>>
>>
>> The VERT2400 antenna is BLACK and made out of PLASTIC. If your "vertical
>> antenna" is copper colored, then you do NOT have a vertical antenna. What
>> you have is the RIGID COAXIAL CABLE which comes with the Quad Patch 2400
>> MHz
>> antenna. This coax needs to be soldered to the GREEN PCB with 4 squares
>> on
>> it labeled "Highgain Antennas 2.4-2.48 GHz". See the datasheet for the
>> Quad Patch antennas for more info on how to do this.
>>
>> To reiterate --
>> The VERT2400 is BLACK PLASTIC
>> The VERT900 is BLACK PLASTIC
>> The VERT400/1200 is a thin BLACK WIRE ANTENNA
>>
>>
>> The copper colored rigid line is RIGID COAXIAL CABLE. It needs to be
>> soldered to the Quad Patch 2400, Yagi 1200, or Yagi 900 GREEN PCB antenna
>> which came with it.
>>
>> Thanks,
>> Matt
>>
>>
> 
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Re: [Discuss-gnuradio] parallel data reception

[Jason Uher]

> I am using USRP1 + RFX2400.
>
> You know there are two antenna ports on RFX2400 daughter card those are RX2,
> TX/RX. Is it possible to use both these ports in parallel for data
> reception. If yes then pelase provide me little clue how I should do it, or
> may be refer me to some existing example.
>
> I have two RFX2400 daughter cards and my problem is to use two different
> ports for data reception, it doesnt matter if I use two ports on a single
> card (i.e RX2, and RX/TX), or two ports on two different cards (e.g. RX2 on
> each card). Please let me know which one is possible and easier to implement
> and please also refer me to some application where I can find relevant code.
>

I do not believe it is possible to receive data from the TX/RX and TX
port simultaneously, I believe the are tied to the same set of ADCs.
You should use two RFX cards if you are planning on doing MIMO
reception.  Check in the examples section, I don't think there is a
specific 2 antenna receive example with the 2400's; but there is a 4rx
fm receiver that you should be able to extrapolate from.

Jason


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[Discuss-gnuradio] Quesion on AUX ADC of AD9862

[Su Jinzhao]

Hi,

I want to read RSSI value using analog AUX ADC, I think we can read RSSI
through AUX_ADC_A1 pin of AD9862, I looked through the code
of usrp_read_aux_adc in file
/root/gnuradio/gnuradio-3.1.3/usrp/host/lib/legacy/usrp_primes.cc,

bool
usrp_read_aux_adc (struct usb_dev_handle *udh, int slot,
   int which_adc, int *value)
{
  *value = 0;
  int   which_codec;
  if (!slot_to_codec (slot, &which_codec))
return false;
  if (!(0 <= which_codec && which_codec < 2)){
fprintf (stderr, "usrp_read_aux_adc: invalid adc = %d\n", which_adc);
return false;
  }
  unsigned char aux_adc_control =
 AUX_ADC_CTRL_REFSEL_A // on chip reference
| AUX_ADC_CTRL_REFSEL_B;// on chip reference
  int   rd_reg = 26;// base address of two regs to read for result
  // program the ADC mux bits
  if (tx_slot_p (slot))
aux_adc_control |= AUX_ADC_CTRL_SELECT_A2 | AUX_ADC_CTRL_SELECT_B2;
  else {
rd_reg += 2;
aux_adc_control |= AUX_ADC_CTRL_SELECT_A1 | AUX_ADC_CTRL_SELECT_B1;
  }
  // I'm not sure if we can set the mux and issue a start conversion
  // in the same cycle, so let's do them one at a time.
  usrp_9862_write (udh, which_codec, 34, aux_adc_control);
  if (which_adc == 0)
aux_adc_control |= AUX_ADC_CTRL_START_A;
  else {
rd_reg += 4;
aux_adc_control |= AUX_ADC_CTRL_START_B;
  }
  // start the conversion
  usrp_9862_write (udh, which_codec, 34, aux_adc_control);
  // read the 10-bit result back
  unsigned char v_lo = 0;
  unsigned char v_hi = 0;
  bool r = usrp_9862_read (udh, which_codec, rd_reg, &v_lo);
  r &= usrp_9862_read (udh, which_codec, rd_reg + 1, &v_hi);

  if (r)
*value = ((v_hi << 2) | ((v_lo >> 6) & 0x3)) << 2;// format as
12-bit
  return r;
}

my question is:
1.The AD 9862 specification says: "The AUX SPI can be enabled and configured
by setting register AUX ADC CTRL. Setting register use pins high enables the
AUX SPI port.", but in the above code AUX_ADC_CTRL_AUX_SPI was not set high(
In my opinion, aux_adc_control should be added with | = AUX_ADC_CTRL_AUX_SPI
because usrp_9862_write and usrp_9862_read all need SPI operation, so we
should enable AUX API), Is this a mistype or another method ?
2.stefan.bruens in the list had said that the low 16 bits is the RSSI value,
I want to know why did the above code combine the high and low 16-bit and
format the data into 12-bit ?
3. Even with the RSSI value (int type), what should I do to convert that
value into dBm unit ?

Thanks.
-- 
Su Jinzhao

-- 
Su Jinzhao
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Re: [Discuss-gnuradio] how to achieve change values of parameters at runtime

[Tom Rondeau]

Sheshanandan KN wrote:

Hi all,
Please ignore the previous mail. It is not complete. It was sent accidently.

Thanks Eric... I will be more specific about the problem here it is...

 I am trying to combine the spectrum sense and ODFM Tx code together
 using multi flow graph concept. I idea is to sense the spectrum for
 occupancy and if free, use that frequency for OFDM transmission. So
 far I have achieved the connection between spectrum sense flow graph
 and the OFDM Tx flow graph. I am taking both the spectrum sense
 parameters and OFDM Tx parameters together at the time of
 initialization.
 The code is working fine performing the spectrum sense and ofdm
 transmission. But the frequency at which the OFDM transmission is
 happening is not at the frequency sensed to be free. Instead it is
 happening at the initialized frequency (--tx-freq parameter). I want
 this parameter to be changed at runtime. I have given following piece
 of code for the same:

 class my_top_block(gr.top_block)

   self.sp_sense = spectrum_sense()
   self.ofdm_tx = ofdm_transmit()

   self.connect(ofdm_tx)
   self.connect(sp_sense)


 tx = my_top_block()

Now, in the main program, I do something like this:

if power < threshold:
   print 'spectrum is free'
   tx.ofdm_tx._tx_freq = m.center_freq

Then I perform ofdm transmission. But the last statement here has no
effect in the execution. Please let me know what is the mistake with
this kind of change of parameter value. I am looking to have this kind
of runtime change in value of parameter.
  


tx.ofdm_tx._tx_freq is just a variable holding the frequency, but does 
not set it.


You have to re-tune the usrp (tb.set_freq(new_freq)).

Tom




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[Discuss-gnuradio] parallel data reception

[kaleem ahmad]

Hello everyone,

I am using USRP1 + RFX2400.

You know there are two antenna ports on RFX2400 daughter card those are RX2,
TX/RX. Is it possible to use both these ports in parallel for data
reception. If yes then pelase provide me little clue how I should do it, or
may be refer me to some existing example.

I have two RFX2400 daughter cards and my problem is to use two different
ports for data reception, it doesnt matter if I use two ports on a single
card (i.e RX2, and RX/TX), or two ports on two different cards (e.g. RX2 on
each card). Please let me know which one is possible and easier to implement
and please also refer me to some application where I can find relevant code.

Thanks and Best Regards
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[Discuss-gnuradio] About Top_block

[Chun-Ta Kung]

Hello,
I am new to gnuradio, and I felt confused with "glue the blocks", such as
hier_block2.
I have read gnu tutorial by Mr. Shen and I understood there were multiple
attributes to describe a block, such as endpoint and edge.
But when I tried to analyze an example of code, there was no such block of
code to elaborate on
them. I cannot understand how python knows how to connect between two
blocks.
Which signal plays as input or output to connect between them? And am I able
to use only line-by-line code to replace partial usage of glue(
top_block.connect(block1,block2)) ?

p.s I thought this should be  a preliminary question. There must be
something seriously wrong with my concept. Please correct it if you don't
mind spending some time typing.

Thank you all
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Re: [Discuss-gnuradio] BBN 802.11b updated: Barker spreading works

[Colby Boyer]

I think I fixed the one hier block error.

Also I set the default int/dec rate to 4 and spb to 25.  This should give 1
MBaud/sec after despreading.  Maybe this will work with 802.11 chipset? Im
not sure if the sinc shaping has the right bandwidth (barker code smoothing)
after these changes.

--Colby

On Mon, Jun 15, 2009 at 10:48 AM, Douglas Geiger <
doug.gei...@bioradiation.net> wrote:

> If I get some free time (probably next week), I'll try it out between my
> USRP2's. Thanks!
>  Doug
>
> On Sun, Jun 14, 2009 at 10:45 PM, Colby Boyer wrote:
>
>> Hey All,
>>
>> I fixed the code in the pkt.py file so that DSSS with the barker code now
>> works.  The main issue was the length of the barker interpolation filter was
>> way too short (like 8).  I changed it so that it is now sample per baud *
>> 11.  Additionally the barker sequence needs to be time reversed on the
>> receive side so that the correct match filter is formed. Otherwise the nice
>> autocorrelation properties of barker will go away.
>>
>> I am only able to test it using the test script with a channel filter and
>> gaussian noise and so far it has been a success there with both 1 and 2 Mbps
>> modulation rates.  Can someone test with USRP2?  Also the BER seems to be
>> much better as compared to just the RRC filter.  Hopefully this will make
>> TX/RX much more robust.
>>
>> The code is uploaded to the CGRAN svn under the branch/usrp2_version in
>> the bbn project directory.
>>
>> Cheers,
>> Colby Boyer
>>
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>
> --
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> doug.gei...@bioradiation.net
>
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