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If I have Digital Matter's Yabby Edge Cellular devices and would be interested in knowing and reporting their locations, is there any sensible way to achieve that other than using Digital Matter's Location Engine service (for a fee)?

The devices will have SIM cards installed and the necessary server connection configured so that I'd have full access to the data they report. So my concern is "only" about transforming that raw data from the devices to more human-friendly location information.

This particular model has Semtech's LR1110 chip inside, so the location data includes GNSS, WiFi and cell tower information. I think I could use existing third-party services to get a rough location based on the wifi and cell tower data, but haven't really found any good spec to interpret the raw GNSS data (i.e. the "NAV message" the chip creates, which is some kind of a binary format).

Based on my online research, it's looking more and more likely that all implementations that exist for this purpose actually use Semtech's GNSS solver in the background, including the afore-mentioned Location Engine by DM. So there might not even be a generally available spec for the format — but I'd be happy to be proven wrong.

Has anyone done something like this successfully?

Addition: I realized I'll have direct access only to the payload from the Yabby device which I believe doesn't send the chip's NAV message in its original form (although I might be wrong). So my first task is to get the raw GNSS data from that payload.

MJV
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  • You could get the NAV message and directly solve it with loracloud.com It appears that the first 4k decodes would be free and then not too bad after that. https://www.loracloud.com/#pricing You may have to strategize about when you will want to do repeated decodes. Perhaps just cache the NAV messages and only decode on demand ? – kalyanswaroop Oct 24 '23 at 15:23
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    You can try asking semtech or loracloud for the details of the message. If you do get the decoding protocol, the NAV message will still only be about satellite signal data. You'll need to use something like loracloud to infer location from that. If you are planning to take on that kind of a science project for fun, here's an alternative. https://www.telesens.co/2017/07/17/calculating-position-from-raw-gps-data/ – kalyanswaroop Oct 24 '23 at 15:30
  • Thank you for the comments, and especially that link! I'm aware of it being a bit challenging doing everything from scratch, but I'll see if it's at all feasible. I also realized that the first hurdle I have is actually the Yabby's payload which I believe doesn't include the NAV message from the chip as is, but in some modified form... (I'll add this to the question also.) – MJV Oct 25 '23 at 07:10

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