Re: [time-nuts] Bricked Garmin GPS 18x LVC
> If you open it up, then simply connect a load resistor, perhaps in the > neighborhood of 100 ohms (but definitely not a direct short!) across the > super cap to drain it faster. I couldn't open mine up. I got one into a useless state. I don't know how I did it, but it wasn't updating firmware. Mine recovered after a while, but I don't know how long it took. I tossed it on the junk pile because it was useless. Eventually, I tried again and it worked. Note that trying too soon probably charges up the super cap and thus restarts the clock. -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Bricked Garmin GPS 18x LVC
That worked for mine a while back. I bricked it and my attempts at resuscitation failed. I put it in my "probably junk" container. Shortly after that, I moved. With the hassle of packing, moving, unpacking, I forgot it completely. Weeks later, I came across it, applied power, and it sprang to life anew. So don't give up. On Saturday, February 23, 2019, Jason Rabel via time-nuts < time-nuts@lists.febo.com> wrote: > That page you linked to says: > > "I am reminded by Dave Hart that it was due to a firmware bug that bricks > the unit until it's left off power long enough to drain the capacitor that > retains its settings, sort of a poor-man's NVRAM. This can take some > weeks." > > Or I suppose if you are impatient you could open it up and de-solder the > super-cap if you don't want to wait weeks for it to drain on its own. > *Maybe* you will get lucky and that's all it will take? > > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to http://lists.febo.com/mailman/ > listinfo/time-nuts_lists.febo.com > and follow the instructions there. > -- ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Clock project request from IEEE
Hi, On 2019-02-22 19:31, Tom Van Baak wrote: I received the following email and permission to post it on time-nuts: Hello, I am the executive editor of the IEEE's flagship magazine, IEEE Spectrum. I recently acquired a TAPR "Pulse Puppy" and I am intrigued by the idea of using it to build a very precise clock that I would share with Spectrum's readers. I would like to partner with an engineer with experience in digital clocks, who would be credited as co-author on this project. Can you suggest someone who might be interested in this project? I would be much obliged if you had some suggestions. Kind regards, -Glenn Glenn's contact info is: Glenn Zorpette g.zorpe...@ieee.org You can just imagine all the many ways the project could head. Send Glenn a note if you want to help. Or post here if you have suggestions. I think we should contribute with our wealth of knowledge. There is several aspects that would form a digital clock. Many of the pieces is readily available, but we rarely put them together in a system. The TAPR Pulse Puppy is a nice little thing. I don't have one myself, but I can see how it could be useful, so thanks for making it aware of it. The Pulse Puppy obviously solves two things, one having a crystal oscillator and output a divided down signal. To build a clock system we should consider from where we get the time, and how we maintain it. These days the answer will be a GPS module which output it's time in serial form, such as the NMEA output format. That will give us the date and time of day that the PPS output represents, in UTC, and then the PPS pulse would give us the phase. The upside of this is that we get the date and time, but we don't get it adjusted to our local time-zone, we also depends strictly on the presence of the GPS signal. Also, the PPS pulse varies due to GPS properties as well as the clock-pulse assignment causing the sawtooth error. As widely known in the group, sawtooth error corrections is available over the serial interface from several receivers. Further, to make a more quiet source you want to filter out some of the GPS noise. This is where the Pulse Puppy can come at handy, as you can steer the oscillator with the GPS PPS pulse and sawtooth corrections, measure the time-difference and then create a servo-loop to steer the oscillators frequency and phase to an average of that from the GPS. The produced PPS pulse can be made more quiet for the short term stability while following the GPS long-term. In that regard we can filter and get a more stable clock. Another drawback may be that we loose GPS signal. There are many possible sources for that, but regardless which source, one needs to cover up the loss. This you do with hold-over, which is the secondary function of an oscillator. During hold-over the steering of the oscillator should be such that it minimize the time-error of a properly operating time and that of the clock in the oscillator. This is in it's most trivial form achieved by ensuring that the frequency steering of the oscillator is maintained as if it was locked to the GPS. The hold-over properties to a high degree depends on how well the oscillator is steered, and how stable the oscillator is to start with, but it ends being a material sport in that you go from TCXO, small OCXO, bigger OCXO, double-oven OCXO, rubidium clock, cesium clock etc. The GPS module has a small TCXO, but for these purposes you probably want to have something better. The digital clock part would at first look very trivial, it has a simple clock counter that counts 24 hours, 60 minutes and 60 seconds. OK, so we need to set this clock. Oh, we might have time-zones. Oh, we might have shifts to and from daylight savings. Oh, we might have leap-seconds. Already there we have a little bit of added complexity. Nothing that can't be handled thought. Also, we want to set the time from the GPS module, so that would require us to have a serial link just to get the NMEA data or similar at least. We probably want to get additional data to be warned about leap-seconds, get the UTC-GPS offset, GPS week number etc. A separate serial link would probably be useful to set time-zone data or set the time from another source, such as a computer timed with NTP. It may also be interesting to encode time to be sent out. Serial interface, IRIG-B or similar. Now, as we look at this, we cover quite a bit, and you can go into depths to do this better, as needed in professional needs. However, I also see a potential to teach several different concepts that comes together in a DIY project, which also may be very handy. If done with a little bit of care, we can teach proper terms to be scientific and educational in one end, while also being very hands on and useful in the other. At the same time we can "crash" into some of the challenges that the professional world sees, and also lots of people needs to be educated in
Re: [time-nuts] Bricked Garmin GPS 18x LVC
If you open it up, then simply connect a load resistor, perhaps in the neighborhood of 100 ohms (but definitely not a direct short!) across the super cap to drain it faster. Dana On Sat, Feb 23, 2019 at 8:00 AM Jason Rabel via time-nuts < time-nuts@lists.febo.com> wrote: > That page you linked to says: > > "I am reminded by Dave Hart that it was due to a firmware bug that bricks > the unit until it's left off power long enough to drain the capacitor that > retains its settings, sort of a poor-man's NVRAM. This can take some > weeks." > > Or I suppose if you are impatient you could open it up and de-solder the > super-cap if you don't want to wait weeks for it to drain on its own. > *Maybe* you will get lucky and that's all it will take? > > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Bricked Garmin GPS 18x LVC
Hi, I don’t know if you saw, but on the same page it is mentioned that it may un-brick itself after being left powered off for a long time - weeks. Hope you get it back. > Le 23 févr. 2019 à 09:41, Anthony Dunne a écrit : > > Hi everyone > > I am hoping someone will have some information on how to unbrick a Garmin GPS > 18x LVC? > > I was trying to rollback the firmware on the unit because I was experiencing > similar issues to what is described here: > https://satsignal.eu/ntp/Garmin-GSP18x-LVC-firmware-issue.htm > > The unit kept randomly dropping the configuration I set up on it. > > I could see no way to rollback the firmware from the current 4.00 to 3.90, so > I renamed the 3.90 firmware to make it 4.10 (bad idea I hear you say). > > All seemed to go well with it erasing the previous firmware and installing > the "new" firmware, but now I think I have bricked the unit as I am getting > no response at all. > > Is there any way that you know of to reset the unit, perhaps by connecting > two pins or something similar? > > Thank-you > > > > Anthony > New South Wales > Australia > > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. I am not a a vegetarian because I love animals. I’m a vegetarian because I hate plants. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Bricked Garmin GPS 18x LVC
That page you linked to says: "I am reminded by Dave Hart that it was due to a firmware bug that bricks the unit until it's left off power long enough to drain the capacitor that retains its settings, sort of a poor-man's NVRAM. This can take some weeks." Or I suppose if you are impatient you could open it up and de-solder the super-cap if you don't want to wait weeks for it to drain on its own. *Maybe* you will get lucky and that's all it will take? ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Clock project request from IEEE
Hi, This request interests me a lot because there is not a good technical product on the market. I would like something similar to the model 6460 TRAK Systems but with more advanced features such as a synchronization within 10nS with an external clock and a clock synchronization from GPS using both the NMEA code using also a PPS input in order to eliminate the delay due to the serial port communication. Unfortunately I do not have the skills to participate in this project but I sincerely hope that some brilliant mind among you can accommodate the request. Tom for example? Luciano Da "time-nuts" time-nuts-boun...@lists.febo.com A "Discussion of precise time and frequency measurement" time-nuts@lists.febo.com Cc Data Fri, 22 Feb 2019 10:31:06 -0800 Oggetto [time-nuts] Clock project request from IEEE I received the following email and permission to post it on time-nuts: > Hello, > > I am the executive editor of the IEEE's flagship magazine, IEEE Spectrum. > I recently acquired a TAPR "Pulse Puppy" and I am intrigued by the idea of > using it to build a very precise clock that I would share with Spectrum's readers. > > I would like to partner with an engineer with experience in digital clocks, who > would be credited as co-author on this project. > > Can you suggest someone who might be interested in this project? I would be > much obliged if you had some suggestions. > > Kind regards, > -Glenn Glenn's contact info is: > Glenn Zorpette > g.zorpe...@ieee.org You can just imagine all the many ways the project could head. Send Glenn a note if you want to help. Or post here if you have suggestions. Thanks, /tvb ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
[time-nuts] Bricked Garmin GPS 18x LVC
Hi everyone I am hoping someone will have some information on how to unbrick a Garmin GPS 18x LVC? I was trying to rollback the firmware on the unit because I was experiencing similar issues to what is described here: https://satsignal.eu/ntp/Garmin-GSP18x-LVC-firmware-issue.htm The unit kept randomly dropping the configuration I set up on it. I could see no way to rollback the firmware from the current 4.00 to 3.90, so I renamed the 3.90 firmware to make it 4.10 (bad idea I hear you say). All seemed to go well with it erasing the previous firmware and installing the "new" firmware, but now I think I have bricked the unit as I am getting no response at all. Is there any way that you know of to reset the unit, perhaps by connecting two pins or something similar? Thank-you Anthony New South Wales Australia ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
