Howto : adding Galileo to Spark (or other DJI drones)
8436 10 2018-2-13
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Matioupi
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Flight distance : 922569 ft
France
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Obvisouly, all operations described hereafter under your only responsability...

1. Open you drone and take the GNSS board apart, this is really easy with the Spark and there are plenty of video on how to do that (youtube keyword : Spark tear down)

2. On Spark, the GNSS board looks like : https://photos.app.goo.gl/uc9ZAEEKQPogizhO2

you can see 4 usefull terminals : Vin (power input : 5V) Gnd : ground, TX RX (uart serial port transmit and receive). Gnd can actually be accessed from almost all large metalized areas on the PCB.

3. with tape, mask all other parts that you do not want to touch/connect . I used small alligatorcables to hook to Vin, Tx, Rx (https://www.adafruit.com/product/1008)

https://photos.app.goo.gl/6Ywz05RVy5HhrJaA3

4. Connect other ends to a USB-TTL cable like this : https://www.adafruit.com/product/954 (colors of wires on adafruit cable match the one on my pictures)

5. Download and install u-blox configuration software : https://www.u-blox.com/en/product/u-center-windows

you'll easily be able to connect to the receiver (just select the usb/serial port installed when you hooked the cable to your computer on the small connect icon submenu). If you are not leaving in a cave and did this outside or close to a windos, you should see the gui of u-center populated :

https://photos.app.goo.gl/UH9THQpZs3vgQP2z1 (this one is from a P4 Pro receiver)

6. Open View / Configuration View menu and select the line "GNSS (GNSS Config line)"

7. Check the "enable" check box in front of Galileo and then press the "Send" button at bottom of screen. The u-blox M8030-KT chip inside Spark (and otehr DJI drones) is actually capable of 3 out of 4 available constellations and only 2 are activated from factore settings. You can also allow SBAS (not included in the 4 constallations) those satellites broadcast ionospehere models that increase accuracy. If you wait long enough and the antenna of your device has a good sky view, you'll see galileo satellites poping up in the sky view.
There are other settigns you can change, e.h. in "NAV5" page, I set the  fix type to 3D only (dont want any horizontal only fixes which are very  unreliable), i personnaly increased the elevation mask from 5 to 10°  because noisy satellites low to the horizon would be worst than nothing  in my opinion. Don't forget to save the configuration before unplugging.

8. Go to Menu receiver / action / save config in order to flash the new configuration in the receiver

Then unplug you USB cable (will power off receiver). You can re-plug to test that configuration remains across power-off/on

9. Reinstall everything and enjoy... Galileo already has quite a lot of satellites. I usually have 4-7 available above me. 4 of them are under commissionning (launched but not active in the constellation) and 4 more will be launched  in 2018 : https://www.gsc-europa.eu/system-status/Constellation-Information

I tested that the configuration you set is not changed by the drone itself (I powered up and flew the machine, everything perfect and then removed gnss board again, hooked to u-center again, galileo and other settings were still there)

Now the real question is : why do DJI not enable this by default when machines get out of factory... They could also enable this by a simple software configuration : the u-blox protocol is documented and they could send the commandfrom the app or aircraft firmware (or combination) to allow this new constellation or other settings without even need to open the drone...

This really looks like a TLDR from DJI on u-blox operating manual... https://www.u-blox.com/en/produc ... oduct_filter%3A2696


2018-2-13
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Grmachine
lvl.4
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Great information, it’s an adventure I don’t think I will try until my warranty and DJI Care expire. But still great info.
2018-2-13
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Matioupi
lvl.4
Flight distance : 922569 ft
France
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Grmachine Posted at 2018-2-13 08:46
Great information, it’s an adventure I don’t think I will try until my warranty and DJI Care expire. But still great info.

I can understand that... I also hope that users can push DJI forward... In my opinion, this is also the role of such forum to put a little pressure on vendor !

And yes, i'm expecting more than a  "our engineer will work on this blablabla" pre-made reply of moderators...
2018-2-13
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LouisP
Second Officer
Flight distance : 41952 ft
United States
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Good information and I can understand why another constellation would be better but, have you seen a real improvement in the spark  (or other drone?)   If you have enough sats to lock on either GPS or GLONASS  isn't that enough?  I guess what I am asking is if this mod is an improvment for normal flight or is it only an improvement if you happen to be in an area that is particularly hard to get good GPS reception?
2018-2-13
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Matioupi
lvl.4
Flight distance : 922569 ft
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LouisP Posted at 2018-2-13 11:52
Good information and I can understand why another constellation would be better but, have you seen a real improvement in the spark  (or other drone?)   If you have enough sats to lock on either GPS or GLONASS  isn't that enough?  I guess what I am asking is if this mod is an improvment for normal flight or is it only an improvement if you happen to be in an area that is particularly hard to get good GPS reception?

It's not an improvment... until it will be a definitive one...

What I mean is that adding extra satellite will probably add little to positionning accuracy,or flight quality but it will improve robustness, especially if you have tree/building around that will mask some satellites. The more are remaining in direct line of sight, the better it is. So adding more satellites should prevent some unwanted switches into ATTI mode.

Also setting the fix mode to 3D only (instead of auto 2D/3D) will maybe need more time to get fix and "GPS" mode on the app, but it will prevent dubious fixes to be taken into account.

2018-2-13
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LouisP
Second Officer
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Matioupi Posted at 2018-2-13 11:59
It's not an improvment... until it will be a definitive one...

What I mean is that adding extra satellite will probably add little to positionning accuracy,or flight quality but it will improve robustness, especially if you have tree/building around that will mask some satellites. The more are remaining in direct line of sight, the better it is. So adding more satellites should prevent some unwanted switches into ATTI mode.

Thanks for the reply.  I agree and well said.. not much of an improvement until it is needed but then it is a big improvement :-)   Unfortunately the problems that spark has are more with the way it uses the GPS data from the module as opposed to bad data from the GPS module.  It would have been great to hear that a simple setting like this fixed some of sparks problems but I think it all boils down to the hardware that they chose to use in the spark.  One IMU and one GPS doesn't leave enough redundancy for the computer to decide what to do when they do not agree.   Like someone else said.. I might try this modification after my warranty and refresh run out.  Thanks.
2018-2-13
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Matioupi
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Flight distance : 922569 ft
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LouisP Posted at 2018-2-13 12:10
Thanks for the reply.  I agree and well said.. not much of an improvement until it is needed but then it is a big improvement :-)   Unfortunately the problems that spark has are more with the way it uses the GPS data from the module as opposed to bad data from the GPS module.  It would have been great to hear that a simple setting like this fixed some of sparks problems but I think it all boils down to the hardware that they chose to use in the spark.  One IMU and one GPS doesn't leave enough redundancy for the computer to decide what to do when they do not agree.   Like someone else said.. I might try this modification after my warranty and refresh run out.  Thanks.

To be honest, I first took advantage of a dead P4 Pro from work to test configuring the receiver before openning my own Spark...

Now i'd really like to understand why DJI is not taking full advantage of the chip capabilities... it's as if you where buying a car with airbags but its delivered disabled and without the key to enable it...

There is no extra fee to pay to u-blox, it's only a matter of configuration, and once again, they could still enable it on all their drones (M8030-KT based) by a small firmware change...
2018-2-13
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LouisP
Second Officer
Flight distance : 41952 ft
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Matioupi Posted at 2018-2-13 12:20
To be honest, I first took advantage of a dead P4 Pro from work to test configuring the receiver before openning my own Spark...

Now i'd really like to understand why DJI is not taking full advantage of the chip capabilities... it's as if you where buying a car with airbags but its delivered disabled and without the key to enable it...

Agree.. It would not be difficult at all for them to send the config change when the spark boots up. But, they obviously don't configure the GPS module at all and just take the default settings as "good enough" because if they did send a config to the module, your settings would be overwritten. So I guess the question falls to the chip manufacturer.  I suppose they will start setting the new constellation to 'on' by default when all the satellites are turned on.
2018-2-13
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Matioupi
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Flight distance : 922569 ft
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LouisP Posted at 2018-2-13 12:33
Agree.. It would not be difficult at all for them to send the config change when the spark boots up. But, they obviously don't configure the GPS module at all and just take the default settings as "good enough" because if they did send a config to the module, your settings would be overwritten. So I guess the question falls to the chip manufacturer.  I suppose they will start setting the new constellation to 'on' by default when all the satellites are turned on.

I think they do changed a few settings from default configuration. E.g. they set elevation mask to 5°, i'm not sure of this but I believe the default setting on u-blox devices is 15°)

I also think they are actually sending a few basic configuration frames already : had the receiver output format changed from UBX to NMEA, saved the setting, and after powering up inside the Spark and testing again, it reverted to UBX.

Last poin tis that the app connects to (at least contains) the url to u-blox offline-assist service for fast startup (basically broadcast ephemerids/almanachs so the receiver already has an idea where it is and which satellites to try catching) .
2018-2-13
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Matioupi
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Matioupi Posted at 2018-2-13 22:27
I think they do changed a few settings from default configuration. E.g. they set elevation mask to 5°, i'm not sure of this but I believe the default setting on u-blox devices is 15°)

I also think they are actually sending a few basic configuration frames already : had the receiver output format changed from UBX to NMEA, saved the setting, and after powering up inside the Spark and testing again, it reverted to UBX.

addon : from ublox manual UBX-13003221 - R14 p42 / 376

"AssistNow Offline currently supports GPS and GLONASS. u-blox intend to expand the AssistNow
Offline Service to support other GNSS (such as BeiDou and Galileo) in due course."

Assist offline is the service dji is using to preload the ephemerids in the receiver. Still not having this for other constellations do not prevent using them.
2018-2-13
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moddien
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Germany
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Has anybody tried this with a Mavic 2 yet?
2019-3-4
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