07-05-2021, 03:20 PM
(This post was last modified: 07-05-2021, 03:21 PM by Benatti.)
(06-09-2021, 10:21 AM)wibble Wrote: There's some movement on getting assistance data loading into distros.
OpenSuse have this:
https://build.opensuse.org/package/view_...y?expand=1
Dylan Van Assche has been working on Mobian via egs5-manager as well as upstream ModemManager:
https://gitlab.com/mobian1/devices/eg25-...equests/15
https://gitlab.freedesktop.org/mobile-br...issues/357 Good Morning
Thank you for your attention and I leave a photo that I hope to be able to add in the post with an addition of aluminum paper on the gps antenna, fixed with transparent adhesive tape to make the photo, which considerably increased the signal level, obtaining a good signal-to-noise ratio. best.
I suggest it be researched to confirm and implemented if possible in the next phones, so I hope I could have contributed to this project in some way.
07-06-2021, 02:30 AM
(This post was last modified: 07-06-2021, 02:39 AM by biketool.)
I suppose this is an unusual route to target, but why not a celestial rough fix to give an alternate warm start to AGPS.
With the camera, compass, and gyro all that would be required is to lay the phone on its back at night especially in a low light rural area, during the day put the sun in view of the camera(maybe with a lens cover to prevent burnout) this will place the phone within a few km anywhere as long as the clock is accurate. Setting clock is really all GPS satellites do then we compare the results, I am not sure if commercial ITAR compliant GPS receivers output the raw time component. Even if not what is cool is that you can get within about 15 seconds of real time simply by comparing the arc-distance of the moon from other stars and planets with a Napoleonic era sextant and reference book.
If someone can help with the video matching this dev has been very into projects like this and I think would enjoy being part of the first 'sextant' phone https://github.com/kenyoung
@ Benatti was that trial and error or a calculated size and position of aluminium? From one of the photos I saw recently it appears the GPS antenna has changed between my Brave Heart and whichever later revision was in the picture, which may be a reason some people are having more problems than others with reception. Unfortunately I don't remember where the photo I saw was. Anyone here have experience with antenna design?
@ biketool That might be a handy way to get approximate location when you're out of mobile data range and have iffy sky view or luck with sat locations, but it's not an alternative to AGPS. I know some gps systems can get a quicker fix if you prime them with rough time and location, but I don't think this is one of them - at least I didn't see it in the GNSS AT command docs. The AGPS provides an alternate source of almanac and ephemeris data to receiving it uninterrupted and error free from the satellite signal, which can be a problem with our poor antenna.
(07-06-2021, 07:24 AM)wibble Wrote: @Benatti was that trial and error or a calculated size and position of aluminium? From one of the photos I saw recently it appears the GPS antenna has changed between my Brave Heart and whichever later revision was in the picture, which may be a reason some people are having more problems than others with reception. Unfortunately I don't remember where the photo I saw was. Anyone here have experience with antenna design?
@biketool That might be a handy way to get approximate location when you're out of mobile data range and have iffy sky view or luck with sat locations, but it's not an alternative to AGPS. I know some gps systems can get a quicker fix if you prime them with rough time and location, but I don't think this is one of them - at least I didn't see it in the GNSS AT command docs. The AGPS provides an alternate source of almanac and ephemeris data to receiving it uninterrupted and error free from the satellite signal, which can be a problem with our poor antenna. It's going to be difficult to explain, because I'm going to write in Portuguese and play it on the translator and then post it, and there are things you need knowledge in electronics to understand.
Due to my knowledge in electronics, the size of the antenna is related to the frequency of the signal to be tuned, which can be tuned by the main frequency or by the harmonic frequencies, and by doubling the size of the antenna, you keep tuning even if it is by the harmonic and double frequency the signal strength at the antenna. Of course, there is a tuning circuit, tuned to the desired frequency, to avoid interference from other signal frequencies.
So, as for the size of the antenna, I already had an idea, and looking at the size of the antenna on the device, you will see that it was approximately the same width and twice the size, adding the antenna of the device with the piece of aluminum paper added, as for her position, it was by trial and error, this being the position that worked best for me.
(07-05-2021, 03:20 PM)Benatti Wrote: (06-09-2021, 10:21 AM)wibble Wrote: There's some movement on getting assistance data loading into distros.
OpenSuse have this:
https://build.opensuse.org/package/view_...y?expand=1
Dylan Van Assche has been working on Mobian via egs5-manager as well as upstream ModemManager:
https://gitlab.com/mobian1/devices/eg25-...equests/15
https://gitlab.freedesktop.org/mobile-br...issues/357 Good Morning
Thank you for your attention and I leave a photo that I hope to be able to add in the post with an addition of aluminum paper on the gps antenna, fixed with transparent adhesive tape to make the photo, which considerably increased the signal level, obtaining a good signal-to-noise ratio. best.
I suggest it be researched to confirm and implemented if possible in the next phones, so I hope I could have contributed to this project in some way.
Have you scratched stock antenna on the phone to get better electrical contact or used some electrically conductive glue? Could you get a better picture of your antenna?
(07-06-2021, 02:30 AM)biketool Wrote: I suppose this is an unusual route to target, but why not a celestial rough fix to give an alternate warm start to AGPS.
...
If someone can help with the video matching this dev has been very into projects like this and I think would enjoy being part of the first 'sextant' phone https://github.com/kenyoung
That is a really cool idea, and MIGHT be practical. In the mean time, how about inputting a rough fix manually? I usually know my lat and lon to the nearest degree, or closer. It wouldn't bother me at all to type in 64N, 145W each time I turn on the GPS.
Pinephone beta edition, convergence model, Mobian Bookworm with Phosh.
10-18-2021, 07:05 AM
(This post was last modified: 10-18-2021, 07:26 AM by wibble.)
(10-17-2021, 04:29 PM)nelstomlinson Wrote: (07-06-2021, 02:30 AM)biketool Wrote: I suppose this is an unusual route to target, but why not a celestial rough fix to give an alternate warm start to AGPS.
...
If someone can help with the video matching this dev has been very into projects like this and I think would enjoy being part of the first 'sextant' phone https://github.com/kenyoung
That is a really cool idea, and MIGHT be practical. In the mean time, how about inputting a rough fix manually? I usually know my lat and lon to the nearest degree, or closer. It wouldn't bother me at all to type in 64N, 145W each time I turn on the GPS.
Are you proposing a manual-entry location provider for geoclue so that apps see the location you entered manually?
Here's a practical example of using an iPhone as a sextant. Note the extra optics required, and the limitation of sensor accuracy, but still better than nothing.
http://www.tecepe.com.br/nav/CamSextant/
(10-18-2021, 07:05 AM)wibble Wrote: Are you proposing a manual-entry location provider for geoclue so that apps see the location you entered manually?
Here's a practical example of using an iPhone as a sextant. Note the extra optics required, and the limitation of sensor accuracy, but still better than nothing.
http://www.tecepe.com.br/nav/CamSextant/ Wibble, I was thinking of giving the GPS its initial fix manually, rather than having it get the info from the cell towers. I do like the thought of having the option to leave GPS off entirely, and provide a manually entered location to any app that wants it.
Pinephone beta edition, convergence model, Mobian Bookworm with Phosh.
(10-19-2021, 12:17 PM)nelstomlinson Wrote: Wibble, I was thinking of giving the GPS its initial fix manually, rather than having it get the info from the cell towers. I do like the thought of having the option to leave GPS off entirely, and provide a manually entered location to any app that wants it.
There's no method of giving the modem your location documented in the GNSS AT command manual, so I'm assuming it's not an option. There may be a way in the native qualcomm interface, but I'm guessing not. The AGPS data you download and feed to the modem is just the almanac and ephemeris data it would otherwise need to receive via the satellite signal, a process that is slow by its nature, and prone to errors due to the poor signal to noise ratio from the small printed antenna in the phone. Without that data it can't calculate a fix. Once it has that data getting the fix is usually quick enough that you wouldn't notice any improvement from telling it roughly where it is.
(10-17-2021, 05:47 AM)EuvzO8 Wrote: Have you scratched stock antenna on the phone to get better electrical contact or used some electrically conductive glue? Could you get a better picture of your antenna?
I have done the same modification as Benatti described. Antennas on the phone have conductive surface, so you don't need to scratch. A little bit of pressure has to be applied to get better contacts between aluminum sheet and antenna.
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