If the gps works well, does that imply librem5-agps is correctly installed and/or updated? Or will updating the almanac always improve things?
From where you downloaded this exactly? Thanks
Sorry, I forgot to provide the link in my post.
I don’t think it’s required nor is it installed by default to my knowledge. I have a second Librem 5 and I don’t recall doing this on it.
I downloaded and installed the above artifact, which installed 4 apps on the home screen. Unfortunately it isn’t clear from the readme how to use these tools to update almanac etc. I have tried them all, but location in maps is still jumping between the place I used to live 18 months ago and and a location close to where I am now (but not closer than a couple hundred meters) and a third place I visited a couple of weeks ago.
Cleary, my GPS isn’t working properly and, as before, seems to have an inherent difficulty in getting a fix.
Any ideas would be welcome.
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Minor progress, X-rays imagining of assembled Librem 5, not much usable to investigate which or unknown variants of GNSS antennas design is used in the actual bought Librem 5.
Have a good GPS Signal and the Position on the Gnome Map. However i installed satellite via flatpack in the not up to date Version 0.4.0 and it have issues like not List the Bars and Throw this Python error:
"NoneType" object has no atribute "get_traces"Will remove that flatpack and try to use flatpack-build or pip and fetch Version 0.4.1 to see if there is some improvement. I saw with thap app some satillites but had no bar as indicator in the view like in this picture.
Is there a way to download some Maps to navigate offline?
I hoped it was solved in Version 0.4.1, the last developer post in your issue report, was not clear. And with flatpack-build i am not sure if i have to run that build commands as user or as root. So i will take some time and wait.
And if nothing work i just can read directly from the Positioning Device (/dev/gnss0, like Skalman described) and save that information to merge it into a gpx File later.
is there a way to test the librem5-agps package, is it ready for testing or does it still need work? the installation instructions dont make sense to me.
It needs more work.
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The interesting thing about Assisted GPS is that you are essentially copying data from one GPS device, which has already downloaded everything, to another GPS device, so that it can start tracking without having to collect the same data, which takes a while and requires a good signal. The store and load commands are built into the GPS device, which uses a simple text based protocol accessed over a serial port. I am not sure if the data is location specific, but it seems to me like someone could run their own AGPS server at home or something, and pull the data from there when turning on GPS on their mobile device.
Almanac is not, but you can only get ephemerides for satellites you’re seeing and can decode signal from.
We actually figured out the format the module uses for its data (mostly) and we’ll be translating publicly available almanac and ephemeris data for all satellites into what the module expects.
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As I have prepared presentation about GPS something like 20 years ago, I remember that each satellite send its almanac repeatedly in subframes of every 30 second frame but then there are multiplexed subframes 4 and 5 which allows to receive whole GPS almanac after 25 frames, i.e. 12.5 minutes. So if the GPS is working (sic…) then after some time you get whole almanac and are prepared for satellites which appears above horizon. You do not get Galileo almanac from GPS satellites and same for Glonas. But if you have even single satellite only from the given network then you can build whole information after relatively long time. For sure, almanac data known in advance can help do get fix much faster.
I expect that Teseo-LIV3 GNSS Module does all that processing from all available sources and utilizes complete almanac data.
The only available source it has is the GPS signal itself (plus past data it stored on its flash). And if you miss a frame, you wait for another cycle. And the tiny smartphone antennas aren’t really optimized for being able to receive data over GPS…
So yeah, without assistance it gets pretty hard for the module to retrieve almanac and ephemerides. Since almanac retrieval can work on multiple channels, under ideal conditions you should be able to get it in about 3 minutes. The conditions are usually far from perfect though, so it can take multiples of 12.5 minutes instead.
By injecting almanac and ephemerides obtained from the Internet, I’m able to reliably get time to first fix down to about a minute, sometimes even just a few seconds. So far I’ve figured out ephemerides for GPS and Galileo and almanac for GPS. I’m almost finished with almanac for Galileo too. From what I’ve seen it shouldn’t be hard to deal with almanac for GLONASS too, but its ephemerides may be trickier (I’m not sure yet where to get all the data the module expects from).
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I contacted Purism support again and asked for detailed photos of the antenna spring contacts. I was very happy about how quick and clearly the person at Purism support responded to all my requests.
I got the following photos and explanation:
Image 1:
Image 2:
Image 3:
Image 4:
Image 5:
explanation:
* Image 1: here are where they are located when looking at the side of the midframe that points towards the back of the phone.
* Image 2: there's the other side, the side from which they are inserted.
* Image 3: here you can see them when taken out, the longer side goes through the hole from the inside, shorter side pointing out towards the inside of the phone.
* Image 4: with the pin pulled out a bit.
* Image 5: fully inserted.
In most cases this should fit pretty snug inside the plastic hole, if it fell out it could be that you pushed on this spring contact from the back side of the phone when removing the midframe. If the midframe is taken out and you press on this spring pin from what would be the back side of the phone, they will pop out.
I also asked if they have service point in the EU to repair the GPS antenna connections (in case I do not dare to take the phone apart in the end), to replace the WiFi module, and to replace my screen that has a crack at the bottom.
All this can be done in a small service center in Germany, Purism support would arrange this:
... it takes a bit more time to repair, but technician there is certified and approved by Purism.
I did not try to check the GPS antenna connections yet, because I want to wait first until the GPS software (gnss-share in particular) is more reliable and mature to rule out a software issue.
Also, no special tools are needed according to Purism support:
There are no specific tools, just a screwdriver and pair of tweezers to gently unhook antenna connectors from the card's connector knobs.
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Interesting. My contact at Purism’s support never came back with any info about this. I will need to have a closer look at those photos when I am at my PC. Never thought those golden metal pieces had anything to do with the GPS antenna, though.
This is of high interest to me as I’m located in Germay. I asked Purism several times if I could buy the new Wifi card and if they could do the swap as payed service, even willing to pay the oversea transport fee. I never got an answer (last time I asked June 7). 
matthias
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In which city are you located?
Near Munich in a smaller village.