FE-.5680A trimming resolution
The Tbolt does not have any sawtooth error or corrections. Its' GPS receiver LO is generated from the 10 MHz oscillator. That's what makes it the best GPSDO out there.
I'm also thinking of porting over much of the Lady Heather t-bolt monitoring stuff to the Arduino.
One thing you can do with a uP based controller is look at the t-bolt's saw tooth error correction and remove a few nS of error.
On Mon, Jan 30, 2012 at 9:47 AM, Mark Sims holrum@hotmail.com wrote:
The Tbolt does not have any sawtooth error or corrections. Its' GPS receiver LO is
generated from the 10 MHz oscillator. That's what makes it the best GPSDO out there.
Inside "Packet 0x8F-AC" (supplemental timing packet) there are two
data fields named "PPSOset and 10MHZOset. Each is a 4-bit signed
integer with units of nanoseconds for PPSOset and in pars per billion
for 10MHZOset. They are used to report an estimate of the PPS and
10MHz signals offset from UTC. Typically the values reported are not
constant and in the single digit range. (I'm reading from section
A.10.31 of the Thunderbolt manual.)
This is what I meant when I said "sawtooth". Maybe the wrong term.
But I think theses numbers can be used in a controller.
Chris Albertson
Redondo Beach, California
Mark,
If you feel adventurous, my GPSMonitor (written in C for the 8051) source
code is available. Development tools including C compiler are free.
Didier KO4BB
On Mon, Jan 30, 2012 at 11:47 AM, Mark Sims holrum@hotmail.com wrote:
The Tbolt does not have any sawtooth error or corrections. Its' GPS
receiver LO is generated from the 10 MHz oscillator. That's what makes it
the best GPSDO out there.
I'm also thinking of porting over much of the Lady Heather t-bolt
monitoring stuff to the Arduino.
One thing you can do with a uP based controller is look at the t-bolt's
saw tooth error correction and remove a few nS of error.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
On Mon, 30 Jan 2012 17:47:54 +0000
Mark Sims holrum@hotmail.com wrote:
The Tbolt does not have any sawtooth error or corrections.
Its' GPS receiver LO is generated from the 10 MHz oscillator.
That's what makes it the best GPSDO out there.
I just wonder, whether one could take a GPS module, like the LEA-6T
and replace the TCXO they have with a VCXO that is phase locked
to the 10MHz reference. Or would that cause too much of the hanging
bridge problem?
Attila Kinali
--
The trouble with you, Shev, is you don't say anything until you've saved
up a whole truckload of damned heavy brick arguments and then you dump
them all out and never look at the bleeding body mangled beneath the heap
-- Tirin, The Dispossessed, U. Le Guin
On Tue, Jan 31, 2012 at 7:52 AM, Attila Kinali attila@kinali.ch wrote:
.... one could take a GPS module, like the LEA-6T
and replace the TCXO they have with a VCXO that is phase locked
to the 10MHz reference....
I'm trying to figure out your goal. The above assumes one already
has a 10MHz reference.
Chris Albertson
Redondo Beach, California
On Tue, 31 Jan 2012 09:32:22 -0800
Chris Albertson albertson.chris@gmail.com wrote:
On Tue, Jan 31, 2012 at 7:52 AM, Attila Kinali attila@kinali.ch wrote:
.... one could take a GPS module, like the LEA-6T
and replace the TCXO they have with a VCXO that is phase locked
to the 10MHz reference....
I'm trying to figure out your goal. The above assumes one already
has a 10MHz reference.
Let's say, i'm building a GPSDO with a high quality OCXO.
Wouldnt it then make sense to lock the reference clock of the GPS
receiver also to that OCXO?
Attila Kinali
--
Why does it take years to find the answers to
the questions one should have asked long ago?
On Tue, 31 Jan 2012 09:32:22 -0800
Chris Albertson albertson.chris@gmail.com wrote:
On Tue, Jan 31, 2012 at 7:52 AM, Attila Kinali attila@kinali.ch wrote:
.... one could take a GPS module, like the LEA-6T
and replace the TCXO they have with a VCXO that is phase locked
to the 10MHz reference....
I'm trying to figure out your goal. The above assumes one already
has a 10MHz reference.
Let's say, i'm building a GPSDO with a high quality OCXO.
Wouldnt it then make sense to lock the reference clock of the GPS
receiver also to that OCXO?
Attila Kinali
Exactly that is the appeal of the Tbolts. What frequency does the uBlox
6T TCXO have? Let us know your progress.
--
Björn
On Tue, 31 Jan 2012 18:50:08 +0100
bg@lysator.liu.se wrote:
Let's say, i'm building a GPSDO with a high quality OCXO.
Wouldnt it then make sense to lock the reference clock of the GPS
receiver also to that OCXO?
Attila Kinali
Exactly that is the appeal of the Tbolts.
Yes, but can this be replicated with a standard GPS module?
And does it have side effects?
What frequency does the uBlox
6T TCXO have?
48MHz as stated in the Timing AppNote.
Let us know your progress.
My current progress is that the uC i wanted to use does not
do what i want. Can anyone recommend a uC with 32bit timers
and IEEE 1588 support?
The alternative would be to use an FPGA, but i'm reluctant to
do that as it makes the whole system a lot more complex.
Attila Kinali
--
Why does it take years to find the answers to
the questions one should have asked long ago?
El 31/01/2012 20:43, Attila Kinali escribió:
My current progress is that the uC i wanted to use does not do what i
want. Can anyone recommend a uC with 32bit timers and IEEE 1588 support?
You can have a look on these
http://www.ti.com/mcu/docs/mculuminaryfamilynode.tsp?sectionId=95&tabId=2597&familyId=1756
Some of them have IEEE-1588, like the LM3S9B96
Regards,
Javier
On Tue, 31 Jan 2012 20:43:35 +0100, Attila Kinali wrote:
My current progress is that the uC i wanted to use does not do what i
want. Can anyone recommend a uC with 32bit timers and IEEE 1588 support?
Some of the ST's supports IEEE-1588
http://www.embeddedstar.com/weblog/2011/09/21/stm32-f4-mcu/
www.mouser.com/pdfdocs/BRSTM32F4_v7final.pdf
I'd suggest a $20 STM32-F4-Discovery (Digikey etc)
http://parts.digikey.com/1/parts/2484058-eval-kit-stm32f-discovery-
stm32f4discovery.html
And a Phy (The mac is in the F4) $10
http://www.ebay.de/itm/DP83848-Ethernet-Physical-Transceiver-RJ45-
connector-control-interface-Board-Kit-/260868624339
Some www-sw is here (German use google translate)
http://www.mikrocontroller.net/topic/237223#2491080
The F4 even supports "Single precision" Floats in HW ,
and has both ADC & DAC (with the ADC/DAC vref pin on external pin).
1G flash , 192k Ram , and it runs 168Mhz.
I think there is 2 x 32bit timers (Fclock/2) , and a fair amount of 16bit
timers.
It comes with build in debugger (proprietarary) , but the debug protocol
has been reversed ... (see texane project) , and afaik it is now suported
in openocd. So arm-gcc & arm-gdb can be used (ie codesourcery).
ST suggests Atollic as "gcc" toolchain , but that's imho "handicapped" in
the free version.
I have earlier suggested the F4-Discovery , as a "Tnut" GPSDO/OCXO/RBXO
controller board.
CFO
On Tue, 31 Jan 2012 21:06:04 +0100
Javier Herrero jherrero@hvsistemas.es wrote:
El 31/01/2012 20:43, Attila Kinali escribió:
My current progress is that the uC i wanted to use does not do what i
want. Can anyone recommend a uC with 32bit timers and IEEE 1588 support?
You can have a look on these
http://www.ti.com/mcu/docs/mculuminaryfamilynode.tsp?sectionId=95&tabId=2597&familyId=1756
Some of them have IEEE-1588, like the LM3S9B96
This was exactly the device i intended to use.
But it doesnt really have 32bit timers. They cascade two 16bit timers
to get 32bit, but then all kind of restrictions apply which make the
timers unusable. And when using 16bit timers, i'll get an overflow
every 800us (at 80MHz clock).
I browsed trough the internets and could find the following devices:
LPC18xx (NXP):
Look nice, but still in development or early production.
I especially like that they (will be) are available in a 200 pin QFP.
This would enable to use all the functions of the chip while still
being able to solder one by hand.
K60 (Freescale): Hell of a confusing documentation. Also quite new.
Have only 16bit timers. A big issue is that they have a crypto unit
on chip, which makes them export restricted. Ie the only way to buy
them is from a local distributor which makes them expensive.
STM32-F2/F4 (ST): ST doesn't want to give me the documentation to those.
(website fails w/o error message)
I havent found any other chips yet. Sofar the options i see are:
- wait for the LPC18xx become available in quanities (can take a year)
- Use a LM3S9B96 together with a small FPGA to implement the counter functions.
Any hints appreciated
Attila Kinali
--
Why does it take years to find the answers to
the questions one should have asked long ago?
If you are willing to use external counters:
Dallas DS2423 Dual 32-bit Counter
Or, if you have an unlimited budget:
http://www.cwcelectronicsystems.com/dual32ct_modulario.html
the word "defense" is prominent here :-).
Or counter products from: http://www.lsicsi.com/
I use encoder interfaces from the last company and recommend them!
Don
Attila Kinali
On Tue, 31 Jan 2012 21:06:04 +0100
Javier Herrero jherrero@hvsistemas.es wrote:
El 31/01/2012 20:43, Attila Kinali escribió:
My current progress is that the uC i wanted to use does not do what
i
want. Can anyone recommend a uC with 32bit timers and IEEE 1588
support?
You can have a look on these
http://www.ti.com/mcu/docs/mculuminaryfamilynode.tsp?sectionId=95&tabId=2597&familyId=1756
Some of them have IEEE-1588, like the LM3S9B96
This was exactly the device i intended to use.
But it doesnt really have 32bit timers. They cascade two 16bit timers
to get 32bit, but then all kind of restrictions apply which make the
timers unusable. And when using 16bit timers, i'll get an overflow
every 800us (at 80MHz clock).
I browsed trough the internets and could find the following devices:
LPC18xx (NXP):
Look nice, but still in development or early production.
I especially like that they (will be) are available in a 200 pin QFP.
This would enable to use all the functions of the chip while still
being able to solder one by hand.
K60 (Freescale): Hell of a confusing documentation. Also quite new.
Have only 16bit timers. A big issue is that they have a crypto unit
on chip, which makes them export restricted. Ie the only way to buy
them is from a local distributor which makes them expensive.
STM32-F2/F4 (ST): ST doesn't want to give me the documentation to those.
(website fails w/o error message)
I havent found any other chips yet. Sofar the options i see are:
- wait for the LPC18xx become available in quanities (can take a year)
- Use a LM3S9B96 together with a small FPGA to implement the counter
functions.
Any hints appreciated
Attila Kinali
--
Why does it take years to find the answers to
the questions one should have asked long ago?
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
--
"Neither the voice of authority nor the weight of reason and argument
are as significant as experiment, for thence comes quiet to the mind."
R. Bacon
"If you don't know what it is, don't poke it."
Ghost in the Shell
Dr. Don Latham AJ7LL
Six Mile Systems LLP
17850 Six Mile Road
POB 134
Huson, MT, 59846
VOX 406-626-4304
www.lightningforensics.com
www.sixmilesystems.com
In message deac00aacc21732c4705e34cd4097d7a.squirrel@www.webmail.montana.com,
"Don Latham" writes:
want. Can anyone recommend a uC with 32bit timers and IEEE 1588
An suitable motherboard and an intel 82599 based ethernet card ?
The latter will set you back approx $700, but $1000 should get you far
in total.
The 82599 has some very interesting time-nuts features with respect
to the GPIO pins. Unfortunately I have not been able to find out if
these pins are accessible on the Intel ethernet cards.
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
If anyone is interested, I have just got hold of a PDF of the Technical Manual TM 5680-0211 for 5680A series Rubidiums.
Please contact me off list for a copy (1M, so too large to post on time-nuts@febo.com)
Rob Kimberley
-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of Attila Kinali
Sent: 31 January 2012 20:47
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] FE-.5680A trimming resolution
On Tue, 31 Jan 2012 21:06:04 +0100
Javier Herrero jherrero@hvsistemas.es wrote:
El 31/01/2012 20:43, Attila Kinali escribi :
My current progress is that the uC i wanted to use does not do what
i want. Can anyone recommend a uC with 32bit timers and IEEE 1588 support?
You can have a look on these
http://www.ti.com/mcu/docs/mculuminaryfamilynode.tsp?sectionId=95&tabI
d=2597&familyId=1756 Some of them have IEEE-1588, like the LM3S9B96
This was exactly the device i intended to use.
But it doesnt really have 32bit timers. They cascade two 16bit timers to get 32bit, but then all kind of restrictions apply which make the timers unusable. And when using 16bit timers, i'll get an overflow every 800us (at 80MHz clock).
I browsed trough the internets and could find the following devices:
LPC18xx (NXP):
Look nice, but still in development or early production.
I especially like that they (will be) are available in a 200 pin QFP.
This would enable to use all the functions of the chip while still being able to solder one by hand.
K60 (Freescale): Hell of a confusing documentation. Also quite new.
Have only 16bit timers. A big issue is that they have a crypto unit on chip, which makes them export restricted. Ie the only way to buy them is from a local distributor which makes them expensive.
STM32-F2/F4 (ST): ST doesn't want to give me the documentation to those.
(website fails w/o error message)
I havent found any other chips yet. Sofar the options i see are:
- wait for the LPC18xx become available in quanities (can take a year)
- Use a LM3S9B96 together with a small FPGA to implement the counter functions.
Any hints appreciated
Attila Kinali
--
Why does it take years to find the answers to the questions one should have asked long ago?
time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
El 31/01/2012 21:47, Attila Kinali escribió:
This was exactly the device i intended to use.
But it doesnt really have 32bit timers. They cascade two 16bit timers
to get 32bit, but then all kind of restrictions apply which make the
timers unusable. And when using 16bit timers, i'll get an overflow
every 800us (at 80MHz clock).
I see... for edge count and edge time, only individual timers and not
concatenates. I've had a look to the LM3S9D96, and it is more or less
the same (the exception is that it is marketed as 4 32-bit timers that
can be used as 8 16-bit timers :) ), and I suspect that all the family
will have similar behaviout. A pity... since for Ethernet it includes
the LAN and PHY on-chip.
Regards,
Javier
On Tue, 31 Jan 2012 21:47:15 +0100, Attila Kinali wrote:
STM32-F2/F4 (ST): ST doesn't want to give me the documentation to those.
(website fails w/o error message)
I have no probs with the ST site (Discovery-F4)
http://www.st.com/internet/evalboard/product/252419.jsp
You want these for the MCU
http://www.st.com/internet/mcu/product/252140.jsp
DataSheet
http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/
DATASHEET/DM00037051.pdf
Errata
http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/
ERRATA_SHEET/DM00037591.pdf
Reference Manual
http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/
REFERENCE_MANUAL/DM00031020.pdf
CFO
The Navsync FTS125 is an example where the GPS receiver engine (the CW25)
is driven by a 20MHz fixed OCXO. At the moment I don't know if the CW25 of
the FTS125 has a specific firmware for that but I suspect that it must be
so. In my opinion it is best to have a tunable OCXO (like the TBolt) to
have the best performance.
On Tue, Jan 31, 2012 at 10:19 PM, cfo xnews2@luna.kyed.com wrote:
On Tue, 31 Jan 2012 21:47:15 +0100, Attila Kinali wrote:
STM32-F2/F4 (ST): ST doesn't want to give me the documentation to those.
(website fails w/o error message)
I have no probs with the ST site (Discovery-F4)
http://www.st.com/internet/evalboard/product/252419.jsp
You want these for the MCU
http://www.st.com/internet/mcu/product/252140.jsp
DataSheet
http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/
DATASHEET/DM00037051.pdf
Errata
http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/
ERRATA_SHEET/DM00037591.pdf
Reference Manual
http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/
REFERENCE_MANUAL/DM00031020.pdf
CFO
time-nuts mailing list -- time-nuts@febo.com
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and follow the instructions there.
On Tue, Jan 31, 2012 at 9:40 AM, Attila Kinali attila@kinali.ch wrote:
Let's say, i'm building a GPSDO with a high quality OCXO.
Wouldnt it then make sense to lock the reference clock of the GPS
receiver also to that OCXO?
Yes, I see. That is exactly what Trimble does in the Thunderbolt.
There is only one OCXO in the T-bolt that is used for both the output
10MHz and to run the receiver. That system works well for them
Chris Albertson
Redondo Beach, California
On Tue, Jan 31, 2012 at 11:43 AM, Attila Kinali attila@kinali.ch wrote:
My current progress is that the uC i wanted to use does not
do what i want. Can anyone recommend a uC with 32bit timers
and IEEE 1588 support?
Does the system need to be small? If not Generic PC hardware can
work. Buy an Intel "Atom" main board. For under $85 you get a
soldered down CPU and all the normal PC stuff, PCI bus and all. The
board I bought does not have a CPU fan and burns all of about 5 watts.
Or you can re-cycle and old notebook computer. If you run Linux
then yes it supports IEEE 1588. There are real-time versions of
linux that give you easy access to low level hardware much like with a
uP.
If you were going to mass produce these you could cut costs but for a
one-off using a $100 PC is reasonable.
Chris Albertson
Redondo Beach, California
Rob, I would be happy to put it on one of my web pages so people could
download it.
On Wed, Feb 1, 2012 at 8:14 AM, Rob Kimberley
robkimberley@btinternet.comwrote:
If anyone is interested, I have just got hold of a PDF of the Technical
Manual TM 5680-0211 for 5680A series Rubidiums.
Please contact me off list for a copy (1M, so too large to post on
time-nuts@febo.com)