NFZ Limit Cannot Take Off After .600 Firmware

[Malavic]

So Malavic your saying once you use the latest version of GO4 that the Mavic returns to normal and ATTI and Opti modes work as before?

If that is the case would it mean that they have now dissabled the ability of the remote itself to take off the craft unless the phones NFZ database is loaded and checked against the phones GPS system.


Rob

I'm not saying that the latest GO4 fixed the NFZ issue. I'm saying that I updated GO4 and I didn't have the NFZ issue that I'd had on the previous night. I'll try it tonight without the tablet and see what happens, both indoors and out.

 

[Daneng]

I would love to hear more on this subject.
If the Mavic can only go into NFZ and GPS mode it means that with no GPS signal the Mavic is dead!
Is there any other drone on the market that cannot take off in ATTI mode?


Rob

Rob,

I checked again and again and observed the following:

When I am indoors with no or very low GPS signal ( max 4 satellites ) I can fly in ATTI Mode or P-Opti Mode.

When displacing myself indoors to a better place , the moment I am receiving 5 to 7 satellites I have the NFZ Limit msg and can't T/O.

After going outside and receiving 9 to 14 satellites I am ready to fly in GPS Mode .

When I return now to the same spot where I had 5 to 7 satellites before and where I had the NFZ Limit message I go directly in ATTI or
P-Opti Mode and do not receive the NFZ Limit messages anymore.

So after a lock on a strong GPS signal you can go indoors and fly in the ATTI or P-Opti mode .

I seems to me that without having received a strong GPS signal and position , the Mavic places you somewhere in a NFZ except when there is no GPS signal at all are very low.

Hope this helps.
Dan.

 

[BorisTheSpider]

I seems to me that without having received a strong GPS signal and position , the Mavic places you somewhere in a NFZ except when there is no GPS signal at all are very low.

Hope this helps.
Dan.

Wow this sucks then for flying in forested areas and other places where you may wish to fly in P-OPTI but you get a weak GPS lock and it won't even take off.

 

[Kilrah]

That's only the first power up after the update.

 

[mobalized]

I would encourage everyone to contact support and let them know this is an problem for you. It seems like it may be isolated since there are only a few of us mentioning this issue. Whether it is a bug or something they implemented the only way to get it fixed is to complain. Their instructions for me were to downgrade firmware which leads me to believe they did not expect this behavior.

 

[mobalized]

That's only the first power up after the update.

It is not for everyone, it did it for every power up I did after the update.

 

[JoostGT3]

I have a feeling that this has to do with a so-called "cold fix":

When firing up a GPS system out of the blue with no prior information about an approximate location, it can often take a very long time to get an accurate position to fly. After that, most GPS systems store the last known position, and when starting it again, it has this as an estimate position. The actual position is based with this estimate position "in mind" and can therefore be determined much quicker than a cold fix.

My assumption is that with the firmware/go4 app update, the last known position was wiped and maybe even replaced with a default value (somewhere in China?), and therefore a cold fix or a fix using that bogus last position, yielding an NFZ reading. After a while the true position becomes known and then the problem disappears.

I had the issue as well, but after the first time, it didn't come back again.

 

[BorisTheSpider]

My assumption is that with the firmware/go4 app update, the last known position was wiped and maybe even replaced with a default value (somewhere in China?).

You could be onto something there. I'm still on firmware .400, but I updated the Go 4 app, and when I went into the new "find my drone" feature to take a look (without turning on or connecting either the drone or controller) it showed the drone as being somewhere in China. It can't gave been the GPS not having got a lock, since I never even turned any drone parts on, just opened the app on my phone, but it seems the last known location had reset.

 

[Malavic]

I have a feeling that this has to do with a so-called "cold fix":

When firing up a GPS system out of the blue with no prior information about an approximate location, it can often take a very long time to get an accurate position to fly. After that, most GPS systems store the last known position, and when starting it again, it has this as an estimate position. The actual position is based with this estimate position "in mind" and can therefore be determined much quicker than a cold fix.

My assumption is that with the firmware/go4 app update, the last known position was wiped and maybe even replaced with a default value (somewhere in China?), and therefore a cold fix or a fix using that bogus last position, yielding an NFZ reading. After a while the true position becomes known and then the problem disappears.

I had the issue as well, but after the first time, it didn't come back again.

I think you're right. I saw no evidence of this issue on my second flight. It also seemed like it picked up GPS sats faster even though it hadn't been powered on in roughly 24 hours. I don't even start the motors until I get GPS and I was surprised when it locked onto 9 sats in 15 seconds after hitting the power button. It usually takes a minute or so because I'm not in a nice clear area. Could just be a coincidence but maybe they are storing more data on last known sats on top of an NFZ map and the firmware update dumps your default position into a NFZ in China.

 

[sabhai miagi]

OK so I changed firmware to .400 and running as you suggested v 4.0.3. Took a flight after the rain died down and the stability was not the same as 600 but I am overall a much happier flier. No errors, no NFZ limits etc. I shall now sit back and read and see what others have to say after next weeks firmware update .

 

[Daneng]

That's only the first power up after the update.

For me it happens on every new power up ....

 

[Andrew F]

Why not down grade to .400 while you still have the chance?

I'm sticking with .4 until forced to change. Works "perfectly" for me!

 

[Andrew F]

OK so I changed firmware to .400 and running as you suggested v 4.0.3. Took a flight after the rain died down and the stability was not the same as 600 but I am overall a much happier flier. No errors, no NFZ limits etc. I shall now sit back and read and see what others have to say after next weeks firmware update .

What do you mean "stability?"

 

[Robbyg]

What do you mean "stability?"

He probably needs to re-tweak his control settings. Stability on .4 vs .500 was no different for me.

I do not take DJI seriously when they talk about better RTH and better hovering. Mine has always RTH with 2-3 inches of takeoff point and the hovering has always been rock solid. Maybe they can tweak an extra 1% out of the system but there is no room in those two areas for improvements that are worth sacrificing something else for.

Rob

 

[Andrew F]

He probably needs to re-tweak his control settings. Stability on .4 vs .500 was no different for me.

I do not take DJI seriously when they talk about better RTH and better hovering. Mine has always RTH with 2-3 inches of takeoff point and the hovering has always been rock solid. Maybe they can tweak an extra 1% out of the system but there is no room in those two areas for improvements that are worth sacrificing something else for.

Rob

I didn't know whether he meant physical stability or software / app stability. I'm always shocked at how stable my Mavic is while in the air - certainly when utilizing VPS. I'm using .4 and it could not be more stable.

 

[Malavic]

So I tested without my tablet attached.

I'm in the house, I can fly no issue.

I go outside and as soon as it detects a sat, it goes to NFZ. As soon as the GPS locks, I would assume with 8 sats, hard to say with the little progress bar, it goes into P-GPS and I can take off.

Clearly the intent here is to allow people to use the drone indoors but if it detects you're outside, you can't fly until it's sure you're not in a NFZ.

 

[Andrew F]

If what you are saying is correct, then DJI is defaulting to NFZ and is using GPS to prove the negative. That is disastrous if so.

 

[Malavic]

If what you are saying is correct, then DJI is defaulting to NFZ and is using GPS to prove the negative. That is disastrous if so.

I would like to think I'm wrong here, but this appears to be the case. Maybe it has something to do with the NFZ file that refused to download when I was doing the firmware update.

I hope there is just an error occurring here.

 

[Robbyg]

If what you are saying is correct, then DJI is defaulting to NFZ and is using GPS to prove the negative. That is disastrous if so.

Malavic post seems to be true. So the new policy is guilty until proven innocent That's pretty much the way the legal system works in China so no surprises there.


Rob

 

[Logger]

...
I'm in the house, I can fly no issue.

I go outside and as soon as it detects a sat, it goes to NFZ. As soon as the GPS locks, I would assume with 8 sats, hard to say with the little progress bar, it goes into P-GPS and I can take off.

Clearly the intent here is to allow people to use the drone indoors but if it detects you're outside, you can't fly until it's sure you're not in a NFZ.

I tested mine with S7 edge attached and saw the same thing. Indoors and with no sats at all. Would allow me to take off in Opti mode. Move to near a window. Once it started so receive GPS signals, "NFZ Limit" on RC & "unable to take off" in Go app. In my test it was receiving 8 Sats, no fix.

Move out doors into middle of open sports field. Initially NFZ limit. As soon it gets a fix, NFZ Limit disappears and good to go. Next step was to fly around for 20 minutes.

HOWEVER - After having complete a 22 min flight the issue appears to have gone away.

Turn it on indoors with no Sats. Opti Mode. Put it near window and it has 8 to 9 Sats. It still says ready to go (Vision) Opti mode. So no longer getting the NFZ Limit restriction.

I am not sure what removed the restriction. Could it have been the flight verifying my actually position? Alternatively, perhaps the missing NFZ List downloaded in the background whilst DJIGo was running.

I will be moving my Mav 3500km across the continent today. So will check again tonight to see if the "NFZ Limit" restriction returns at the new location. If it does not, it would suggest the NFZ list was downloaded to fix the issue. If OTOH "NFZ Limit" appears pre fix at new location it would suggest it is an intended restriction imposed until location confidence it met.