[time-nuts] Re: Updated TimeHat image (new gpsd!)

[W7SLS]

Perfect. Thanks 

Sent from my iPhone

> On Oct 22, 2021, at 7:22 PM, John Miller via time-nuts 
>  wrote:
> 
> Hi Scott!
> Thanks for the kind words. Writing out this image to an SD card is fairly 
> easy. Download the file I linked in my first email, then use 7zip to 
> decompress it. Once decompressed, attach your SD card to your computer with a 
> USB SD reader (or attach it directly if your computer has an SD card slot). 
> Once connected, use a tool like win32diskimager or Balena Etcher to write the 
> image to the SD card. Once it’s done, connect the SD back to your Pi, plug it 
> in, and you should be good to go!
> 
> If you want to update the software on your existing TimeHat, these are 
> instructions I already wrote up for someone else:
> 
> First update the OS, DietPi - pretty standard debian update procedure:
> - sudo apt update ; sudo apt upgrade (reboot when completed) 
> - sudo dietpi-upgrade (follow prompts, reboot when completed)
> 
> Build & install the latest version of gpsd:
> - remove the old gpsd source (if there): rm -r ~/gpsd
> - pull the latest gpsd source: git clone https://gitlab.com/gpsd/gpsd.git 
> 
> - build gpsd: cd gpsd ; scons
> - stop gpsd: sudo systemctl stop gpsd
> - install new gpsd: sudo scons install
> - restart gpsd: sudo systemctl start gpsd
> 
> You’re all set!
> 
> Regards,
> John
> 
> 
>> On Oct 22, 2021, at 9:50 PM, W7SLS  wrote:
>> 
>> 1 - you are the best, thanks. 
>> 2 - your priorities seem great (family, work, …., RPi)
>> 3 - may I ask you to CC me if you e-mail someone on how to update?
>> 4 - don’t make a special e-mail for me, I can follow the info below
>> (It is more curiosity… I have 2 timeHats, and can do them one at a time)
>> 
>> Thanks and 73,
>> Scott W7SLS
>> 
>> Sent from my iPad
>> 
 On Oct 22, 2021, at 6:12 PM, John Miller via time-nuts 
 mailto:time-nuts@lists.febo.com>> wrote:
>>> 
>>> Hello all,
>>> Here’s an updated system image for the TimeHat - including the latest 
>>> versions of gpsd, chrony, and DietPi. I had been meaning to get this image 
>>> out sooner, but things have been pretty busy lately between work and family.
>>> 
>>> https://millerjs.org/files/TimeHat32_20211022.img.xz 
>>> >>  >
>>> 
>>> The file is a 918MB xz compressed disk image, with an md5 of 
>>> 097e5b0008849dcccfc8131a4d4ba0c9 if you want to verify your download. When 
>>> decompressed, the resulting image will be ~4GB and can be written out to an 
>>> MicroSD card 8GB or larger. On first boot the root partition will 
>>> automatically expand to fill the entire disk. 
>>> 
>>> Aside from the new software versions, everything should be exactly the 
>>> same. Credentials are still timehat/timehat, it will pick up an IP address 
>>> from your DHCP server automatically, it will have ssh listening on port 22, 
>>> and it has a status web page on port 80.
>>> 
>>> If you don’t want to write a new image out for your TimeHat, I can provide 
>>> instructions for how to update it - the process is fairly straightforward. 
>>> 
>>> Don’t hesitate to reach out if you have any issues or questions.
>>> 
>>> Regards,
>>> John Miller
>>> ___
>>> time-nuts mailing list -- time-nuts@lists.febo.com 
>>>  -- To unsubscribe send an email to 
>>> time-nuts-le...@lists.febo.com 
>>> To unsubscribe, go to and follow the instructions there.
>> ___
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> 
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[time-nuts] Re: Updated TimeHat image (new gpsd!)

[John Miller via time-nuts]

Hi Scott!
Thanks for the kind words. Writing out this image to an SD card is fairly easy. 
Download the file I linked in my first email, then use 7zip to decompress it. 
Once decompressed, attach your SD card to your computer with a USB SD reader 
(or attach it directly if your computer has an SD card slot). Once connected, 
use a tool like win32diskimager or Balena Etcher to write the image to the SD 
card. Once it’s done, connect the SD back to your Pi, plug it in, and you 
should be good to go!

If you want to update the software on your existing TimeHat, these are 
instructions I already wrote up for someone else:

First update the OS, DietPi - pretty standard debian update procedure:
- sudo apt update ; sudo apt upgrade (reboot when completed) 
- sudo dietpi-upgrade (follow prompts, reboot when completed)

Build & install the latest version of gpsd:
- remove the old gpsd source (if there): rm -r ~/gpsd
- pull the latest gpsd source: git clone https://gitlab.com/gpsd/gpsd.git 

- build gpsd: cd gpsd ; scons
- stop gpsd: sudo systemctl stop gpsd
- install new gpsd: sudo scons install
- restart gpsd: sudo systemctl start gpsd

You’re all set!

Regards,
John


> On Oct 22, 2021, at 9:50 PM, W7SLS  wrote:
> 
> 1 - you are the best, thanks. 
> 2 - your priorities seem great (family, work, …., RPi)
> 3 - may I ask you to CC me if you e-mail someone on how to update?
> 4 - don’t make a special e-mail for me, I can follow the info below
>  (It is more curiosity… I have 2 timeHats, and can do them one at a time)
> 
> Thanks and 73,
> Scott W7SLS
> 
> Sent from my iPad
> 
>> On Oct 22, 2021, at 6:12 PM, John Miller via time-nuts 
>> mailto:time-nuts@lists.febo.com>> wrote:
>> 
>> Hello all,
>> Here’s an updated system image for the TimeHat - including the latest 
>> versions of gpsd, chrony, and DietPi. I had been meaning to get this image 
>> out sooner, but things have been pretty busy lately between work and family.
>> 
>> https://millerjs.org/files/TimeHat32_20211022.img.xz 
>> >  >
>> 
>> The file is a 918MB xz compressed disk image, with an md5 of 
>> 097e5b0008849dcccfc8131a4d4ba0c9 if you want to verify your download. When 
>> decompressed, the resulting image will be ~4GB and can be written out to an 
>> MicroSD card 8GB or larger. On first boot the root partition will 
>> automatically expand to fill the entire disk. 
>> 
>> Aside from the new software versions, everything should be exactly the same. 
>> Credentials are still timehat/timehat, it will pick up an IP address from 
>> your DHCP server automatically, it will have ssh listening on port 22, and 
>> it has a status web page on port 80.
>> 
>> If you don’t want to write a new image out for your TimeHat, I can provide 
>> instructions for how to update it - the process is fairly straightforward. 
>> 
>> Don’t hesitate to reach out if you have any issues or questions.
>> 
>> Regards,
>> John Miller
>> ___
>> time-nuts mailing list -- time-nuts@lists.febo.com 
>>  -- To unsubscribe send an email to 
>> time-nuts-le...@lists.febo.com 
>> To unsubscribe, go to and follow the instructions there.
> ___
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[time-nuts] Re: Updated TimeHat image (new gpsd!)

[W7SLS]

1 - you are the best, thanks. 
2 - your priorities seem great (family, work, …., RPi)
3 - may I ask you to CC me if you e-mail someone on how to update?
4 - don’t make a special e-mail for me, I can follow the info below
  (It is more curiosity… I have 2 timeHats, and can do them one at a time)

Thanks and 73,
Scott W7SLS

Sent from my iPad

> On Oct 22, 2021, at 6:12 PM, John Miller via time-nuts 
>  wrote:
> 
> Hello all,
> Here’s an updated system image for the TimeHat - including the latest 
> versions of gpsd, chrony, and DietPi. I had been meaning to get this image 
> out sooner, but things have been pretty busy lately between work and family.
> 
> https://millerjs.org/files/TimeHat32_20211022.img.xz 
> 
> 
> The file is a 918MB xz compressed disk image, with an md5 of 
> 097e5b0008849dcccfc8131a4d4ba0c9 if you want to verify your download. When 
> decompressed, the resulting image will be ~4GB and can be written out to an 
> MicroSD card 8GB or larger. On first boot the root partition will 
> automatically expand to fill the entire disk. 
> 
> Aside from the new software versions, everything should be exactly the same. 
> Credentials are still timehat/timehat, it will pick up an IP address from 
> your DHCP server automatically, it will have ssh listening on port 22, and it 
> has a status web page on port 80.
> 
> If you don’t want to write a new image out for your TimeHat, I can provide 
> instructions for how to update it - the process is fairly straightforward. 
> 
> Don’t hesitate to reach out if you have any issues or questions.
> 
> Regards,
> John Miller
> ___
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[time-nuts] Re: Updated TimeHat image (new gpsd!)

[Bill Beam]

Hello John,

I have been regularly updateing DietPI, now at V 7.7.3.

Is there anything new here?

Regards,
Bill

On Fri, 22 Oct 2021 21:11:54 -0400, John Miller via time-nuts wrote:

>Hello all,
>HereG€™s an updated system image for the TimeHat - including the latest 
>versions of gpsd, chrony, and DietPi. I had been meaning to 
get this image out sooner, but things have been pretty busy lately between work 
and family.

>https://millerjs.org/files/TimeHat32_20211022.img.xz 
>

>The file is a 918MB xz compressed disk image, with an md5 of 
>097e5b0008849dcccfc8131a4d4ba0c9 if you want to verify your 
download. When decompressed, the resulting image will be ~4GB and can be 
written out to an MicroSD card 8GB or larger. On first boot 
the root partition will automatically expand to fill the entire disk. 

>Aside from the new software versions, everything should be exactly the same. 
>Credentials are still timehat/timehat, it will pick up an IP 
address from your DHCP server automatically, it will have ssh listening on port 
22, and it has a status web page on port 80.

>If you donG€™t want to write a new image out for your TimeHat, I can provide 
>instructions for how to update it - the process is fairly 
straightforward. 

>DonG€™t hesitate to reach out if you have any issues or questions.

>Regards,
>John Miller
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>email to time-nuts-le...@lists.febo.com
>To unsubscribe, go to and follow the instructions there.


Bill Beam
NL7F


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[time-nuts] Updated TimeHat image (new gpsd!)

[John Miller via time-nuts]

Hello all,
Here’s an updated system image for the TimeHat - including the latest versions 
of gpsd, chrony, and DietPi. I had been meaning to get this image out sooner, 
but things have been pretty busy lately between work and family.

https://millerjs.org/files/TimeHat32_20211022.img.xz 


The file is a 918MB xz compressed disk image, with an md5 of 
097e5b0008849dcccfc8131a4d4ba0c9 if you want to verify your download. When 
decompressed, the resulting image will be ~4GB and can be written out to an 
MicroSD card 8GB or larger. On first boot the root partition will automatically 
expand to fill the entire disk. 

Aside from the new software versions, everything should be exactly the same. 
Credentials are still timehat/timehat, it will pick up an IP address from your 
DHCP server automatically, it will have ssh listening on port 22, and it has a 
status web page on port 80.

If you don’t want to write a new image out for your TimeHat, I can provide 
instructions for how to update it - the process is fairly straightforward. 

Don’t hesitate to reach out if you have any issues or questions.

Regards,
John Miller
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[time-nuts] Re: GPS D (i.e. gpsd) roll over bug..Oct 24th

[Poul-Henning Kamp]

Björn writes:

> The L1 C/A was optimised many decades ago. 

The first GPS receiver to use the L1 C/A code took up four full
racks and required to very alert persons to operate.

There is a picture of it in one of the many "History of GPS"
presentations given by the principals of the programme.


-- 
Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
p...@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.
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[time-nuts] Re: GPS D (i.e. gpsd) roll over bug..Oct 24th

[Magnus Danielson via time-nuts]

Chris,

On 2021-10-22 22:18, Chris Caudle wrote:

On Fri, October 22, 2021 12:22 pm, Magnus Danielson via time-nuts wrote:

I find it amusing, as this was discussed on ntp-questions email-list in
mid August 2013, and clearly explained with due references.

According to the problem report this problem was only introduced in 2019,
so seems to be a regression rather than a problem left uncorrected since
2013.

This is correct, but the bug re-introduces the 1024 wrapping issue, 
which should have a basic safetynet after it.


Cheers,
Magnus
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[time-nuts] Re: GPS D (i.e. gpsd) roll over bug..Oct 24th

[Chris Caudle]

On Fri, October 22, 2021 12:22 pm, Magnus Danielson via time-nuts wrote:
> I find it amusing, as this was discussed on ntp-questions email-list in
> mid August 2013, and clearly explained with due references.

According to the problem report this problem was only introduced in 2019,
so seems to be a regression rather than a problem left uncorrected since
2013.

-- 
Chris Caudle

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[time-nuts] Re: GPS D (i.e. gpsd) roll over bug..Oct 24th

[Magnus Danielson via time-nuts]

Björn,

The C/A code format have seen much greater changes before that. It's 
extention from 24 to 32 birds was not small, neither was the addition of 
the GPS-UTC corrections.


Cheers,
Magnus

On 2021-10-22 21:29, Björn wrote:

”It's actually a systemflaw that never was fixed in L1 C/A code. It would have 
been good if they added additional GPS-weeks bits in that signal, but it never 
materialiseras. It did for other newer signals.”

The L1 C/A was optimised many decades ago. How Do you change the bitstream 
definition, considering several satellite generations running in parallel. Some 
approaching 20 years since launch. Many years more since design.

How do you ensure that old and current working C/A-code receivers don’t turn 
into unusable crap?  (Including the systems they reside in)

Systemflaw... for a system designed now yes. For one designed in the 70-ties, 
still running the show No. Not in my view.


/Björn
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[time-nuts] Re: GPS D (i.e. gpsd) roll over bug..Oct 24th

[Bob kb8tq]

Hi

As various GPS module designs done over the last decade or so have shown, you 
*can*
fix this at the module level. Yes, each of those fixes has its drawbacks. 
However, the modern
designs are a lot less likely to “die” 10 or 20 years from now.

….. and to address the inevitable follow up question: 

The receiver can “save” the last date it saw. That becomes the “never before” 
date. If this is
enabled and the receiver gets a spoofed date, that’s a problem. 

You can manually enter a “never before” date. That works fine, except for the 
“manual” part….
Anything that can be done manually could also be done under the control of the 
driver. That 
opens a hacking path. There are a *lot* of things that could brick a receiver 
if the driver is hacked
so this is hardly unique in that regard. 

Bob

> On Oct 22, 2021, at 1:22 PM, Magnus Danielson via time-nuts 
>  wrote:
> 
> Hi,
> 
> On 2021-10-22 17:58, Kevin Rowett wrote:
>> For those using GPSD (https://gpsd.gitlab.io/gpsd/index.html 
>> ) to read GPS receivers, and get the 
>> GPS time, there is a bug that could cause problems on Oct 24th.
>> 
>> 
>> https://us-cert.cisa.gov/ncas/current-activity/2021/10/21/gps-daemon-gpsd-rollover-bug
>>  
>> 
> 
> I find it amusing, as this was discussed on ntp-questions email-list in mid 
> August 2013, and clearly explained with due references. It seems that people 
> did not act. There was a misconception that this was a "receiver error" for 
> which they should not do any fixes. It's actually a systemflaw that never was 
> fixed in L1 C/A code. It would have been good if they added additional 
> GPS-weeks bits in that signal, but it never materialized. It did for other 
> newer signals.
> 
> It seems nothing happen in those 8 years until the patching this year.
> 
> Cheers,
> Magnus
> 
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[time-nuts] Re: GPS D (i.e. gpsd) roll over bug..Oct 24th

[Björn]

”It's actually a systemflaw that never was fixed in L1 C/A code. It would have 
been good if they added additional GPS-weeks bits in that signal, but it never 
materialiseras. It did for other newer signals.”

The L1 C/A was optimised many decades ago. How Do you change the bitstream 
definition, considering several satellite generations running in parallel. Some 
approaching 20 years since launch. Many years more since design.

How do you ensure that old and current working C/A-code receivers don’t turn 
into unusable crap?  (Including the systems they reside in)

Systemflaw... for a system designed now yes. For one designed in the 70-ties, 
still running the show No. Not in my view.


/Björn
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[time-nuts] Downsizing

[Bob Quenelle]

Please contact me off list if you are interested in any of the following

Synergy Systems Lucent M12+ timing receiver with antenna. In shielded box.
$20.

Adafruit Ultimate GPS Breakout with battery clip and SMA to uFL adapter
cable. Purchased 2018, barely used. $15.

Lot of three 10 MHz OCXO's. Two UCT 108663-01 purchased new. One
Oscilloquartz 8663-XS purchased used. $30 for all 3.

Thanks


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[time-nuts] Re: GPS D (i.e. gpsd) roll over bug..Oct 24th

[Magnus Danielson via time-nuts]

Hi,

On 2021-10-22 17:58, Kevin Rowett wrote:

For those using GPSD (https://gpsd.gitlab.io/gpsd/index.html 
) to read GPS receivers, and get the 
GPS time, there is a bug that could cause problems on Oct 24th.


https://us-cert.cisa.gov/ncas/current-activity/2021/10/21/gps-daemon-gpsd-rollover-bug
 



I find it amusing, as this was discussed on ntp-questions email-list in 
mid August 2013, and clearly explained with due references. It seems 
that people did not act. There was a misconception that this was a 
"receiver error" for which they should not do any fixes. It's actually a 
systemflaw that never was fixed in L1 C/A code. It would have been good 
if they added additional GPS-weeks bits in that signal, but it never 
materialized. It did for other newer signals.


It seems nothing happen in those 8 years until the patching this year.

Cheers,
Magnus

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[time-nuts] GPS D (i.e. gpsd) roll over bug..Oct 24th

[Kevin Rowett]

For those using GPSD (https://gpsd.gitlab.io/gpsd/index.html 
) to read GPS receivers, and get the 
GPS time, there is a bug that could cause problems on Oct 24th.


https://us-cert.cisa.gov/ncas/current-activity/2021/10/21/gps-daemon-gpsd-rollover-bug
 



KR, K6TD


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