Send USRP-users mailing list submissions to
[email protected]
To subscribe or unsubscribe via the World Wide Web, visit
http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
or, via email, send a message with subject or body 'help' to
[email protected]
You can reach the person managing the list at
[email protected]
When replying, please edit your Subject line so it is more specific
than "Re: Contents of USRP-users digest..."
Today's Topics:
1. Re: GPSDO Support (Marcus D. Leech)
2. Re: GPSDO Support (Simon HB9DRV)
3. Re: GPSDO Support (Marcus D. Leech)
4. Re: GPSDO Support (Simon HB9DRV)
5. Re: problem using LO offset with USRP1 (Stefano Speretta)
6. Re: Transmission with timestamps (Matthias P. Braendli)
7. Boost Question / Windows (Simon HB9DRV)
8. LFRX Board Q&A (Simon HB9DRV)
9. Re: LFRX Board Q&A (Simon HB9DRV)
10. Re: LFRX Board Q&A (John Malsbury)
11. Re: GPSDO Support (John Malsbury)
12. Re: LFRX Board Q&A (Simon HB9DRV)
----------------------------------------------------------------------
Message: 1
Date: Sun, 03 Jun 2012 12:11:01 -0400
From: "Marcus D. Leech" <[email protected]>
To: [email protected]
Subject: Re: [USRP-users] GPSDO Support
Message-ID: <[email protected]>
Content-Type: text/plain; charset="iso-8859-1"; Format="flowed"
> Hi,
>
> If I have a GPSDO in a N210 do I have to issue any extra commands to
> enable it, or is it really plug-in, connect Trimble Thunderbolt, and
> just use it?
>
> I'm asking because I would only buy this if I have to issue commands,
> otherwise for now it's not necessary (but would be very nice to have).
>
> Simon Brown, HB9DRV
> http://dit-dit-dit.com
>
> Not sent from an iPhone: I don't have one and I don't want one.
>
You have to tell the underlying hardware that you wish it to use the
external 10Mhz and 1PPS references.
--
Marcus Leech
Principal Investigator
Shirleys Bay Radio Astronomy Consortium
http://www.sbrac.org
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.ettus.com/pipermail/usrp-users_lists.ettus.com/attachments/20120603/72d04204/attachment-0001.html>
------------------------------
Message: 2
Date: Sun, 3 Jun 2012 18:16:40 +0200
From: "Simon HB9DRV" <[email protected]>
To: "'Marcus D. Leech'" <[email protected]>,
<[email protected]>
Subject: Re: [USRP-users] GPSDO Support
Message-ID: <[email protected]>
Content-Type: text/plain; charset="us-ascii"
Hi,
Via UHD.dll or flipping switches? It looks like I'll be buying one anyway,
the phase noise spec is very good.
Searching the UHD.dl source code I see this which indicates that it's used
automagically:
"By default, if a GPSDO is detected at startup, the USRP will be configured
to use it as a frequency and time reference. The internal VITA timestamp
will be initialized to the GPS time, and the internal oscillator will be
phase-locked to the 10MHz GPSDO reference. If the GPSDO is not locked to
satellites, the VITA time will not be initialized."
Simon Brown, HB9DRV
<http://dit-dit-dit.com/> http://dit-dit-dit.com
You are standing at the end of a road before a small brick building. Around
you is a forest.
A small stream flows out of the building and down a gully. The sunspot count
is -25.
From: [email protected]
[mailto:[email protected]] On Behalf Of Marcus D. Leech
Sent: 03 June 2012 18:11
To: [email protected]
Subject: Re: [USRP-users] GPSDO Support
Hi,
If I have a GPSDO in a N210 do I have to issue any extra commands to enable
it, or is it really plug-in, connect Trimble Thunderbolt, and just use it?
I'm asking because I would only buy this if I have to issue commands,
otherwise for now it's not necessary (but would be very nice to have).
Simon Brown, HB9DRV
http://dit-dit-dit.com
Not sent from an iPhone: I don't have one and I don't want one.
You have to tell the underlying hardware that you wish it to use the
external 10Mhz and 1PPS references.
--
Marcus Leech
Principal Investigator
Shirleys Bay Radio Astronomy Consortium
http://www.sbrac.org
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.ettus.com/pipermail/usrp-users_lists.ettus.com/attachments/20120603/f1c6dd87/attachment-0001.html>
------------------------------
Message: 3
Date: Sun, 03 Jun 2012 12:36:47 -0400
From: "Marcus D. Leech" <[email protected]>
To: Simon HB9DRV <[email protected]>
Cc: [email protected]
Subject: Re: [USRP-users] GPSDO Support
Message-ID: <[email protected]>
Content-Type: text/plain; charset="iso-8859-1"; Format="flowed"
> Hi,
>
> Via UHD.dll or flipping switches? It looks like I'll be buying one
> anyway, the phase noise spec is very good.
>
> Searching the UHD.dl source code I see this which indicates that it's
> used automagically:
>
> "By default, if a GPSDO is detected at startup, the USRP will be
> configured to use it as a frequency and time reference. The internal
> VITA timestamp will be initialized to the GPS time, and the internal
> oscillator will be phase-locked to the 10MHz GPSDO reference. If the
> GPSDO is not locked to satellites, the VITA time will not be initialized."
>
That is only, as far as I know, for the "in skin" internal GPSDO.
--
Marcus Leech
Principal Investigator
Shirleys Bay Radio Astronomy Consortium
http://www.sbrac.org
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.ettus.com/pipermail/usrp-users_lists.ettus.com/attachments/20120603/98155b3a/attachment-0001.html>
------------------------------
Message: 4
Date: Sun, 3 Jun 2012 23:39:19 +0200
From: "Simon HB9DRV" <[email protected]>
To: <[email protected]>
Subject: Re: [USRP-users] GPSDO Support
Message-ID: <[email protected]>
Content-Type: text/plain; charset="us-ascii"
Hi Marcus,
Thanks - it's the internal GPSDO I'll be using. The oscillator phase noise
is very good.
Simon Brown, HB9DRV
<http://dit-dit-dit.com/> http://dit-dit-dit.com
You are standing at the end of a road before a small brick building. Around
you is a forest.
A small stream flows out of the building and down a gully. The sunspot count
is 285.
From: Marcus D. Leech [mailto:[email protected]]
Sent: 03 June 2012 18:37
To: Simon HB9DRV
Cc: [email protected]
Subject: Re: [USRP-users] GPSDO Support
Hi,
Via UHD.dll or flipping switches? It looks like I'll be buying one anyway,
the phase noise spec is very good.
Searching the UHD.dl source code I see this which indicates that it's used
automagically:
"By default, if a GPSDO is detected at startup, the USRP will be configured
to use it as a frequency and time reference. The internal VITA timestamp
will be initialized to the GPS time, and the internal oscillator will be
phase-locked to the 10MHz GPSDO reference. If the GPSDO is not locked to
satellites, the VITA time will not be initialized."
That is only, as far as I know, for the "in skin" internal GPSDO.
--
Marcus Leech
Principal Investigator
Shirleys Bay Radio Astronomy Consortium
http://www.sbrac.org
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.ettus.com/pipermail/usrp-users_lists.ettus.com/attachments/20120603/d7f01dd6/attachment-0001.html>
------------------------------
Message: 5
Date: Sun, 03 Jun 2012 23:44:59 +0200
From: Stefano Speretta <[email protected]>
To: "[email protected] >> \"[email protected]\""
<[email protected]>
Subject: Re: [USRP-users] problem using LO offset with USRP1
Message-ID: <[email protected]>
Content-Type: text/plain; charset=ISO-8859-15; format=flowed
unfortunately I discovered the problem while using an antenna + LNA
connected to the WBX and changing
the gain of the LNA, or the internal WBX gain or disconnecting the
antenna did not help. To better understand
the problem I terminated the receiver input and, even with a terminated
input, I still see a spike in DC.
I tried removing it using the DC offset compensation or the LO offset
with no luck...
I tried this with 2 different USPR1 and WBX boards and I consistently
see the same thing. Did anybody else experience
the same problem?
Stefano
Il 31/05/2012 15:33, Patrik Tast ha scritto:
> Hi Stefano,
>
>> I am using a USRP1 and I attached 2 50ohm terminators to the two
>> antenna
> Ok, as I understand from your post, you don't want to receive
> anything, just cry?
>
> Remove that 50 ohm thing. Try to connect an antenna and perhaps an
> amplifier in-between then point at a source, then you wont see that
> spike...
>
> ....
> P
>
>
> ----- Original Message ----- From: "Stefano Speretta"
> <[email protected]>
> To: <[email protected]>
> Sent: Wednesday, May 30, 2012 16:55
> Subject: [USRP-users] problem using LO offset with USRP1
>
>
>> Hello,
>>
>> I am seeing a spurious component at DC using a USRP1 and WBX board.
>> Similar problems were already reported several times in the mailing list
>> and
>> the suggestion was to use an offset in tuning to move this DC component
>> out of band.
>>
>> I am trying to do this but I keep seeing the same result (so that DC
>> component in band). I am using a USRP1 and I attached 2 50ohm
>> terminators to the two antenna
>> ports to eliminate signals coming from outside but the DC component is
>> still there, even if I change the RX tuning frequency.
>>
>> If I do not use the LO offset, in my application I set the RX frequency
>> like this:
>>
>> uhd::usrp::multi_usrp::sptr usrp = uhd::usrp::multi_usrp::make(args);
>> ....
>> double freq = 200e6;
>> uhd::tune_result_t tuned = usrp->set_rx_freq(freq);
>>
>> and if I print tuned.to_string I get this:
>> Tune Result:
>> Target RF Freq: 200.000000 (MHz)
>> Actual RF Freq: 199.999723 (MHz)
>> Target DSP Freq: -0.000277 (MHz)
>> Actual DSP Freq: -0.000277 (MHz)
>>
>> If I do an FFT of the received signal it looks like in the
>> no_lo_offset.png that is attached (span is 20 kHz centered around 200
>> MHz and the spike is 15 dB above noise floor).
>>
>> If I set the offset (5 kHz in this case, I tried with other values too
>> and the result is the same) in the tune function, like this:
>>
>> uhd::usrp::multi_usrp::sptr usrp = uhd::usrp::multi_usrp::make(args);
>> ....
>> double freq = 200e6;
>> uhd::tune_result_t tuned = usrp->set_rx_freq(freq, 5000);
>>
>> printing tuned.to_string gives:
>> Tune Result:
>> Target RF Freq: 200.005000 (MHz)
>> Actual RF Freq: 200.004932 (MHz)
>> Target DSP Freq: 0.004932 (MHz)
>> Actual DSP Freq: 0.004932 (MHz)
>>
>> But the FFT shows again that strong DC peak (check lo_offset.png
>> attached). If you look carefully you will see that there is a Gaussian
>> shaped noise around +5 khz
>> which is exactly the noise around DC, so the offset tuning is working
>> fine (you see the same noise around DC in the other picture).
>> The problem is that the peak around DC is always there.
>>
>> I also tried enabling and disabling the rx_dc_offset (using
>> set_rx_dc_offset) but with no luck.
>>
>> The spurious signal that I see is still there if I tune the the receiver
>> to other frequencies (so I do not think this is an harmonic of the
>> internal oscillator). The same peak can also be seen
>> by using rx_ascii_art.
>>
>> Is it possible that there is some rounding error in the cordic or
>> decimation stages leading to this DC error? Or in the conversions in
>> the PC?
>>
>> Does anybody have ideas on what could be the source and how to eliminate
>> this problem?
>>
>> Thanks a lot,
>> Stefano
>>
>
>
> --------------------------------------------------------------------------------
>
>
>
>
>> _______________________________________________
>> USRP-users mailing list
>> [email protected]
>> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
>>
------------------------------
Message: 6
Date: Mon, 04 Jun 2012 10:55:46 +0200
From: "Matthias P. Braendli" <[email protected]>
To: [email protected]
Subject: Re: [USRP-users] Transmission with timestamps
Message-ID: <[email protected]>
Content-Type: text/plain; charset=ISO-8859-1
On 06/02/12 22:59, Josh Blum wrote:
>> What is the best way to make the USRP reconsider the timestamps while
>> the stream runs ? Is there a better way than dropping a packet, thereby
>> creating an underrun ?
>>
> Basically, set the end of burst on the last TX packet.
> Then send the next packet with a new time.
>
> The examples/tx_bursts.cpp should demonstrate this.
I cannot do an end of burst in regular intervals, because that always
generates late packets. However, if I set EOB once when I have a
discontinuity in my timestamps, it seems to be okay.
How do I have to handle the async burst ACK packets ? And what do I gain
by doing recv_async_msg() ? (Besides knowing that I had underruns or
late packets, which is quite useful. If I check for underruns and late
packets myself, can I suppress the printing of 'U' and 'L' to the console ?)
Thanks for your prompt answer !
Matthias
------------------------------
Message: 7
Date: Mon, 4 Jun 2012 12:16:17 +0200
From: "Simon HB9DRV" <[email protected]>
To: <[email protected]>
Subject: [USRP-users] Boost Question / Windows
Message-ID: <[email protected]>
Content-Type: text/plain; charset="us-ascii"
Hi,
I'm dynamically loading the UHD.dll (latest unstable) and need to know how
to release resources so that the DLL will exit cleanly.
How do I (should I) delete my instance of usrp created with
uhd::usrp::multi_usrp::make ?
How do I (should I) delete my instance of rx_streamer created with
usrp->get_rx_stream ?
Apart from this problem I'm a happy bunny J !
The DLL hangs as below:
SDRSourceEttus.dll!boost::detail::sp_counted_base::release()
Line 103 C++
SDRSourceEttus.dll!boost::detail::shared_count::~shared_count() Line 309
C++
SDRSourceEttus.dll!boost::shared_ptr<uhd::usrp::multi_usrp>::~shared_ptr<uhd
::usrp::multi_usrp>() + 0x2f bytes C++
SDRSourceEttus.dll!CSDRSourceEttusApp::~CSDRSourceEttusApp()
+ 0x4e bytes C++
SDRSourceEttus.dll!`dynamic atexit destructor for 'theApp''()
+ 0x21 bytes C++
SDRSourceEttus.dll!_CRT_INIT(void * hDllHandle, unsigned long
dwReason, void * lpreserved) Line 415 C
SDRSourceEttus.dll!__DllMainCRTStartup(void * hDllHandle,
unsigned long dwReason, void * lpreserved) Line 526 + 0x13 bytes
C
SDRSourceEttus.dll!_DllMainCRTStartup(void * hDllHandle,
unsigned long dwReason, void * lpreserved) Line 477 C
ntdll.dll!LdrpUnloadDll() - 0x13ee bytes
Simon Brown, HB9DRV
http://dit-dit-dit.com
Not sent from an iPhone: I don't have one and I don't want one.
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.ettus.com/pipermail/usrp-users_lists.ettus.com/attachments/20120604/eda574ce/attachment-0001.html>
------------------------------
Message: 8
Date: Mon, 4 Jun 2012 13:21:19 +0200
From: "Simon HB9DRV" <[email protected]>
To: <[email protected]>
Subject: [USRP-users] LFRX Board Q&A
Message-ID: <[email protected]>
Content-Type: text/plain; charset="us-ascii"
Hi,
Just replaced the WBX with the LFRX (AB), using latest unstable UHD.dll
1) No antennas listed via get_rx_antennas
2) No sensors listed via get_rx_sensor_names
3) Calling usrp->get_rx_sensor("lo_locked") blows up inside UHD.dll,
stack available if needed
4) Board is working
Onwards and upwards.
Simon Brown, HB9DRV
http://dit-dit-dit.com
Not sent from an iPhone: I don't have one and I don't want one.
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.ettus.com/pipermail/usrp-users_lists.ettus.com/attachments/20120604/2173f210/attachment-0001.html>
------------------------------
Message: 9
Date: Mon, 4 Jun 2012 13:59:44 +0200
From: "Simon HB9DRV" <[email protected]>
To: <[email protected]>
Subject: Re: [USRP-users] LFRX Board Q&A
Message-ID: <[email protected]>
Content-Type: text/plain; charset="us-ascii"
Same with the Basic RX board.
Question: as there are two antenna connectors on the LFRX and Basic RX
boards, how do I switch them? I can't find a data sheet anywhere.
Simon Brown, HB9DRV
<http://dit-dit-dit.com/> http://dit-dit-dit.com
You are standing at the end of a road before a small brick building. Around
you is a forest.
A small stream flows out of the building and down a gully. The sunspot count
is 285.
From: [email protected]
[mailto:[email protected]] On Behalf Of Simon HB9DRV
Sent: 04 June 2012 13:21
To: [email protected]
Subject: [USRP-users] LFRX Board Q&A
Hi,
Just replaced the WBX with the LFRX (AB), using latest unstable UHD.dll
1) No antennas listed via get_rx_antennas
2) No sensors listed via get_rx_sensor_names
3) Calling usrp->get_rx_sensor("lo_locked") blows up inside UHD.dll,
stack available if needed
4) Board is working
Onwards and upwards.
Simon Brown, HB9DRV
http://dit-dit-dit.com
Not sent from an iPhone: I don't have one and I don't want one.
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.ettus.com/pipermail/usrp-users_lists.ettus.com/attachments/20120604/8e3737fa/attachment-0001.html>
------------------------------
Message: 10
Date: Mon, 04 Jun 2012 08:53:51 -0700
From: John Malsbury <[email protected]>
To: [email protected]
Subject: Re: [USRP-users] LFRX Board Q&A
Message-ID: <[email protected]>
Content-Type: text/plain; charset="iso-8859-1"; Format="flowed"
There are two SMA connectors that can be used together as an I/Q pair or
separately as an IF interface. While you could hypothetically connect
two antennas right to LFRX/BasicRX, you'll see the best performance with
external filters and LNA in place.
I've attached a document which illustrates how to configure the frontend
selection with subdevice specification in UHD or the UHD block in GRC.
-John
On 6/4/2012 4:59 AM, Simon HB9DRV wrote:
>
> Same with the Basic RX board.
>
> Question: as there are two antenna connectors on the LFRX and Basic RX
> boards, how do I switch them? I can't find a data sheet anywhere.
>
> Simon Brown, HB9DRV
> http://dit-dit-dit.com <http://dit-dit-dit.com/>
>
> You are standing at the end of a road before a small brick building.
> Around you is a forest.
>
> A small stream flows out of the building and down a gully. The sunspot
> count is 285.
>
> *From:*[email protected]
> [mailto:[email protected]] *On Behalf Of *Simon HB9DRV
> *Sent:* 04 June 2012 13:21
> *To:* [email protected]
> *Subject:* [USRP-users] LFRX Board Q&A
>
> Hi,
>
> Just replaced the WBX with the LFRX (AB), using latest unstable UHD.dll
>
> 1)No antennas listed via get_rx_antennas
>
> 2)No sensors listed via get_rx_sensor_names
>
> 3)Calling usrp->get_rx_sensor("lo_locked") blows up inside UHD.dll,
> stack available if needed
>
> 4)Board is working
>
> Onwards and upwards.
>
> Simon Brown, HB9DRV
> http://dit-dit-dit.com
>
> Not sent from an iPhone: I don't have one and I don't want one.
>
>
>
> _______________________________________________
> USRP-users mailing list
> [email protected]
> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.ettus.com/pipermail/usrp-users_lists.ettus.com/attachments/20120604/a3e9a2c1/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: application_note_frontends_subdevices_antenna_ports.pdf
Type: application/pdf
Size: 430903 bytes
Desc: not available
URL:
<http://lists.ettus.com/pipermail/usrp-users_lists.ettus.com/attachments/20120604/a3e9a2c1/attachment-0001.pdf>
------------------------------
Message: 11
Date: Mon, 04 Jun 2012 08:57:42 -0700
From: John Malsbury <[email protected]>
To: [email protected]
Subject: Re: [USRP-users] GPSDO Support
Message-ID: <[email protected]>
Content-Type: text/plain; charset="iso-8859-1"; Format="flowed"
Simon,
If you follow the instructions here, and burn the EEPROM, the USRP will
be configured to select the GPSDO 10 MHz and 1 PPS by default. As
indicated in the installation instructions provided with the GPSDO, you
will have to move a jumper that will connect the GPSDO 10 MHz, and
disconnect the external 10 MHz reference. You should not need to do
anything with the .hdl code.
Have I properly understood your questions?
-John
On 6/3/2012 2:39 PM, Simon HB9DRV wrote:
>
> Hi Marcus,
>
> Thanks -- it's the internal GPSDO I'll be using. The oscillator phase
> noise is very good.
>
> Simon Brown, HB9DRV
> http://dit-dit-dit.com <http://dit-dit-dit.com/>
>
> You are standing at the end of a road before a small brick building.
> Around you is a forest.
>
> A small stream flows out of the building and down a gully. The sunspot
> count is 285.
>
> *From:*Marcus D. Leech [mailto:[email protected]]
> *Sent:* 03 June 2012 18:37
> *To:* Simon HB9DRV
> *Cc:* [email protected]
> *Subject:* Re: [USRP-users] GPSDO Support
>
> Hi,
>
> Via UHD.dll or flipping switches? It looks like I'll be buying one
> anyway, the phase noise spec is very good.
>
> Searching the UHD.dl source code I see this which indicates that
> it's used automagically:
>
> "By default, if a GPSDO is detected at startup, the USRP will be
> configured to use it as a frequency and time reference. The
> internal VITA timestamp will be initialized to the GPS time, and
> the internal oscillator will be phase-locked to the 10MHz GPSDO
> reference. If the GPSDO is not locked to satellites, the VITA time
> will not be initialized."
>
> That is only, as far as I know, for the "in skin" internal GPSDO.
>
>
>
>
> --
> Marcus Leech
> Principal Investigator
> Shirleys Bay Radio Astronomy Consortium
> http://www.sbrac.org
>
>
> _______________________________________________
> USRP-users mailing list
> [email protected]
> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.ettus.com/pipermail/usrp-users_lists.ettus.com/attachments/20120604/b747c18f/attachment-0001.html>
------------------------------
Message: 12
Date: Mon, 4 Jun 2012 17:58:18 +0200
From: "Simon HB9DRV" <[email protected]>
To: "'John Malsbury'" <[email protected]>,
<[email protected]>
Subject: Re: [USRP-users] LFRX Board Q&A
Message-ID: <[email protected]>
Content-Type: text/plain; charset="us-ascii"
Excellent info, now why didn't I find this earlier J ?
Simon Brown, HB9DRV
<http://dit-dit-dit.com/> http://dit-dit-dit.com
You are standing at the end of a road before a small brick building. Around
you is a forest.
A small stream flows out of the building and down a gully. The sunspot count
is 285.
From: [email protected]
[mailto:[email protected]] On Behalf Of John Malsbury
There are two SMA connectors that can be used together as an I/Q pair or
separately as an IF interface. While you could hypothetically connect two
antennas right to LFRX/BasicRX, you'll see the best performance with
external filters and LNA in place.
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.ettus.com/pipermail/usrp-users_lists.ettus.com/attachments/20120604/cad18ecc/attachment-0001.html>
------------------------------
_______________________________________________
USRP-users mailing list
[email protected]
http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
End of USRP-users Digest, Vol 22, Issue 4
*****************************************
