I have left it alone hanging outdoors for hours…
I now start to suspect it never fully downloads the almanac. To preserve power it goes into sleep mode right after it gets a fix and reports that over the LoRaWAN.
Yup, that’s what people do, seems very reasonable thing to do, but ends up with just fragments. The almanac is good for 180 days, so at least once every couple of months the GPS needs to run for 20 minutes with good view of the sky - so once you get a good fix, leave it be for 15 minutes.
Sometimes it’s worth powering up the GPS for 30 seconds every 25 minutes to get the ephemeris data so you always get a hot fix - although that needs refining if a satellite you have ephemeris data is out of view, which means the almanac is used to find the missing satellite - you need 4 for a goodish fix.
This may be a better power strategy than turning on less frequently but then needing more time to get the fix in the first place. Hmmm, something to try that I hadn’t thought of (mostly as I now have decent set of power monitors) to see if this is the case.
Summary:
First run for at least 15 minutes with good view of sky - this can be done pre-deployment on desktop power as long as the deployment zone is within 100km or so
Subsequent runs, hot fix as required but at least once every 25 minutes wait for a minimum of 4 satellites and let it run for 30 seconds from when you’ve got the 4th satellite.
If occasional fix requirements, ensure the GPS is on for 15 minutes once every couple of months to ensure it has a good clean copy of the almanac.
If the GPS has been dormant for a while (you will know this either via RTC or the reported time from the first satellite), then run it for 15 minutes so it has a good clean copy of the almanac.
Bear in mind that the ephemeris and almanac are moving data, so it can’t piece together yesterday pieces with todays.
That is something you can change to the GPS being on all the time IIRC. That will of course drain the battery fast(er).
@kersing @descartes you seem to think I have full control over how the unit behaves 
But I am using the Dragino LGT92 with the default firmware. I am a simple user that can just about manage to set the available AT commands. I am not able or capable to programm the unit in the ways you propose. Turning the GPS on all the time for instance is not a setting that is available with the factory firmware.
But if you are a software developer and would like to rewrite some of the code to test for yourself, you can. The firmware is open source: GitHub - dragino/LGT-92_-LoRa_GPS_Tracker: Software Source code for LoRa_GPS_Tracker
Yes it it is: AT+FTIME=0
Also depends on how you are using the device - if it’s for your own use, just run it with FTIME=0 once every two months for a full almanac, the rest of the time you can run with the default of 150 seconds.
Or find a programmer to alter the published source code!
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Ah, I didnt spot that one. Will definitely give that a try.
Thx!
Left it 1 hour outside with GPS always on. Now I also have GPS fix indoors 
Next: I will revert to FTIME=150 and see if I indeed have a much faster fix after each sleep period.
Edit: unfortunately outdoor with clear skyview again takes up to a minute. Indoor fix never happens anymore 
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Thanks for pointing me in the right direction. Just a side node:
If I follow the link: Base64 to hex: Encode and decode bytes online - cryptii
And I input AT+MD=0 to Base64, it displays hex = 01 3f 8c 0f
And not pQA=.
But if I input the value at " Schedule downlink" it accepts only Hex 01 3f 8c 0f and not pQA= anyway. So I think i’m good. So I don’t get it or I wonder how you managed to make this example since i’m only able to enter numbers and not letters in the Payload field 
No dont enter the AT command. You should enter the hex downlink command that you can find in the user manual of yne LGT92. Not all AT commands have a downlink equivalent.
Oh, you might be correct about that. For the mqtt interface you need to convert it to base64 first. But when entering it directly into the webinterface I think you can/must indeed fill in the hex numbers. I just quickly created the screenshot for you and mistakenly filled in the base64 command. So forget about the base64 stuff. 
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Hmm tried to input these data Messaging > Downlink > Payload…port 1 and 2, scheduled download on and off. But no response at all from the LGT92.
AT+TDC=60000 // Set Transmit Interval (TDC) = 60 seconds
0100003C
AT+MD=0 (movement detect off)
01 3f 8c 0f
AT+FTIME=150
0xAA 00 96
Going to try USB > TTL adapter now.
That is not the correct command. It should be
A5 00
Check the user manual
Hi there,
I use the decoder from
https://www.dragino.com/downloads/index.php?dir=LGT_92/Decoder/
Unfortunately I always have the problem that it sends 0 values for Lang and Long. Has someone optimized the decoder so that only valid position values are processed?
If anyone is interested in this Node-RED flow. You can use it to send settings to the LGT92 via TTN, and it displays the location and dashboard info from the LGT92.
Get it from here: https://www.thethingsnetwork.org/forum/t/node-red-flow/54959/2
Not found 
What ?? Are there private threads? I will just copy the whole thing here… Hang on…
EDIT: I REMOVED THE JSON EXPORT SINCE THE MODERATOR IS NOT VERY SUPPORTIVE OF MY POST
I created an export of my flow. Copy and paste above JSON into the Import screen of Node-RED. MQTT client, Dashboard and Worldmap must be installed in Node-RED palette.
Edit: I just tested it myself, and it works fine if you know how to select and drag to the right for a minute or so
I have put a GIGANTIC amount of time in this flow. So I do hope it is appreciated 
Setup after import into Node-RED:
- Go to the console of TTN.
- Find your applicationID and LGT92 DeviceID
- In application go to the tab ‘integrations’
- Under MQTT you can setup a username and password (=api key)
- Fill in the username, password, applicationID and deviceID in the MQTT node ‘LGT92 Downlink’
If targeting TTN you might want to consider FUP and amend (as in significantly increase!) the set Tx interval =60seconds option…even 300sec too often if running at higher SFs…
Also hidden later post to give you chance to edit post and remove solicitation… wrong message and wrong place for such. By all means add PayPal or Patreon links to any (e.g. github) repos you may but please not on direct forum posts…
That is only intended for testing purposes. Was really helpful for me when testing a new device. Default interval of the device is 5 minutes, but only when in motion.
I do all this for the community. I hope people find it useful, as well as I find other peoples work and information most useful. I removed the voluntary donate link. Etiquette on this seems to differ from forum to forum. Sorry if I offended anyone.
As do we all… none of us paid to do this, we are all volunteers…a few minutes browsing different threads Would have told you this approach not normal this forum. Still all good now.
We hear “…it’s only for…” all the time. That does not patch the FUP breach, also be aware even 5 mins risks breach with anything other than lowest SFs, so perhaps apply some conditioning logic e.g. if SF =12 then limit =24 per day or whatever… 30s air time allowed under FUP… if running for shorter time then logic may allow more for short period say 3hrs then force off for next 21 etc… search forum for discussions of tracker type applications. (Note: not against trackers as I have several and use regularly (daily!) for community or client coverage checks and mapping, you just have to be careful and/or limit use time…)
Well @Jeff-UK, the tone of your feedback is not very supportive.
I created a Node-RED flow for my own use. I spent an enormous amount of time creating it. I would not have posted it here if @stj was not asking me if I would share it. I decided to put even more time in it to make the flow publishable and write some setup instructions. I though the community would be thankful, but now I feel I wasted my time just to get your sour remarks.
I don’t intend to hijack this thread to have a fight about this. But I am feeling so frustrated by your feedback that I just had to write this.
Just my feedback to you 
It wasnt intented to have a tone and I guess others will judge if it has one - it was intended to be factual, informative and neutral.
Many of us create work related to LoRa, LoRaWAN and TTN and make it available to the forum. Many of us contribute and post information and provide assistance to the community and to forum members and our local community users. Some of us spend hundreds of hours a month contributing and moderating, personally I also give away nodes and Gateways to help expand the network and have deployed over 40 GW’s as part of my personal estate, across the 7 communities I have initiated and probably another dozen where I contribute or am active, as well as collaborating with others to deploy some 150-200 other gws…
…the key point is (on this forum atleast) we do not follow up our posts and contributions with requests for donations(*) and links to pay by Paypal…sorry if you think this means your efforts are not appreciated but I can assure you that is not the case - all genuine contributions are truely welcome. I celebrated my 4th anniversary with TTN (& the forum) just last week and think the number of times I have seen this is not even a handful…just saying!
(*) if we did a) the forum would be very cluttered and b) the likes of @kersing, @descartes @bluejedi and a whole host of current active contributors (sorry guys & girls & others genders, you are far too many to list but you know who you are!) might be very wealthy indeed and the predecessors on the moderators team and major contributors like Borroz, Arjan et al would be similarly so…
Your feedback is noted 