Semtech LR1110 GPS coordinates from GNSS

I see, thank you for the additional clarification. Yes, I had seen that information before, but I had some doubts because when discussing with colleagues, I sometimes get the impression that the terrestrial and aerial applications might not be on the same frequency bands, which is why I asked the question to remove the uncertainty. Thank you as well for the confirmation.

Where else are you asking these questions? I’m curious to know where else has information on LW via satellite!

No need to post the same response paragraph twice, just tag the people you are aiming at.

Hello, what is the format of the file that is sent to the GNSS when it is operating in assisted mode? And what should its size be?

The WHOLE schematic, link to PDF, would be far more informative.

From your previous “wondering about” questions and this “wondering about the MCU using SPI vs the I2C”, I wonder what you are actually trying to do here as most MCUs have both SPI & I2C and the LR1110 isn’t an MCU so the most reasonable conclusion is that you are a student with an oversized project or working somewhere and they have tasked you with close to Mission Impossible at this level

I think this confirms my suspicions. Apart from not being a proxy for Google searches, the whole point of the LR1110 GNSS implementation is that it doesn’t use AGPS as it doesn’t actually do the whole of GNSS.

@descartes I think you misunderstood me because I am not saying it is an MCU. Moreover, I understood what I wanted to know on this topic by analyzing the schematic. Thank you.

@descartes What do you mean it doesn’t do the entire GNSS? Are you telling me the technical documentation is not correct? I’m not someone who does software but I’m trying to understand a software topic that was suggested to me to see if I can help at the hardware level. Thank you for your response and have a good day.

I mean that the LR1110 doesn’t resolve the location on the chip. It packages up the signals that it hears and sends a summary for further processing on a cloud server which then figures out the location. This is to save power on the device.

It’s still not really clear what the end point of all of this is, you’re giving us sketchy info and asking questions that are available in the product docs or via Google.

As we don’t actually know what problem you are trying to solve and it’s not clear why your software colleagues can’t explain these things to you, this topic doesn’t seem to be going anywhere!

It got to my knowledge that TTN has a service to solve cloud-based GNSS data from LoRaWAN devices. It’s also known as low power GNSS.

Do you have any reference / doc about it?

The LoRa Cloud integration was recently removed as it is not available anymore. You can read more about it here. You now need to use specially licensed providers.. meh.

(Although the biggest ‘meh’ is that the on-chip output is limited to 1/2048th tiles of the globe while I’m confident that it knows its position much more accurately.)

I see. Thanks for your answer.

It looks like this technology is not very extended in the market. I’m expecting 20-30 meters accuracy and this limitation may be related to the chip output limitation you are commenting and the network bandwidth capabilities.

Do ytou have any experience on that?

LoRa Cloud (ignoring that it is not available anymore here) should be capable of roughly that level of accuracy.

The LR1110 has two options: 1) do a short GNSS receive (few seconds I believe should be enough) and output the proprietary blob that can be decoded by the LoRa Cloud, and 2) do a proper GNSS receive (up to a few minutes) and decode on-chip.

The latter is IMO the much preferred option as it doesn’t require any external dependencies, subscriptions etc. But the resolution that you can request from the chip butchers the earth into 2048 lines North to South and 2048 lines East to West, effectively resulting in tiles of 24×24km. The only thing that is good for, is praying that you guess well which language they speak there.

Note that I have never tried LoRa Cloud myself, I’ve only tried on-chip geo-location. I wish someone is able to find out how the proprietary blob is structured so we can get some better estimate..