Advanced falls out of GPS mode after take off

Meta4

Moderator
Staff Member
Premium Pilot
Joined
Jan 8, 2014
Messages
14,901
Reaction score
8,904
This flight is a little different in that GPS reception was quite normal until 3:32.2 when the GPS Health dropped from 5 to zero, but satellite numbers stayed healthy.
There were Speed Error warnings which indicates that the GPS data was not accurate and caused the drone to get incorrect speed data.

It's hard to believe that two different drones are acting similarly, receiving GPS data, appearing to get location information, but have GPS Health of zero.

Is there any noticeable effect on the flight characteristics?
I would wonder if there's something in the local environment that causing GPS problems?

To investigate this possibility, you should drive some distance away and try flying somewhere else.
And see if the same issues persist.
 
Joined
Jul 2, 2021
Messages
27
Reaction score
0
Age
55
It is just what I asked for ... and as I said, there was no charge for it
Your flight data shows that something odd is going on with the GPS.
I've not seen anything like it before and can't think what might cause it.

It's showing 11 sats for most of the flight, which is an appropriate number for a P3 Standard.
It's recording a home point and the flight track shows that it's getting GPS position data throughout the flight.
But the GPS health shows as 0/5 for the whole flight.


The flight track looks like you had full control.
What do you mean about control was lost?
I sent the wrong flight log that one is for my standard sorry I sent a second its here:
DJI Flight Log Viewer - PhantomHelp.com this one shows some weird stuff from my P3A.
 
Joined
Jul 2, 2021
Messages
27
Reaction score
0
Age
55
This flight is a little different in that GPS reception was quite normal until 3:32.2 when the GPS Health dropped from 5 to zero, but satellite numbers stayed healthy.
There were Speed Error warnings which indicates that the GPS data was not accurate and caused the drone to get incorrect speed data.

It's hard to believe that two different drones are acting similarly, receiving GPS data, appearing to get location information, but have GPS Health of zero.

Is there any noticeable effect on the flight characteristics?
I would wonder if there's something in the local environment that causing GPS problems?

To investigate this possibility, you should drive some distance away and try flying somewhere else.
And see if the same issues persist.
Thanks,

I will do that next weekend, back on my head tomorrow.

Thanks Pete
 

Meta4

Moderator
Staff Member
Premium Pilot
Joined
Jan 8, 2014
Messages
14,901
Reaction score
8,904
Could it be something to do with flight controller,,heaps of speed errors,,heaps of sats,,incorrect imu reading,,motor obstruction,,could the main board be faulty ??
The data comes from a P3 Standard and a P3 Adv
Two different drones both showing issues with a lot of similarities.
The Motor Obstructed error is clearly not correct, since the drone was flying at the time and continued to.
The Speed Error is GPS related (speed comes from calculations using GPS position data).

If the data is to be believed, something bad happened around 4:55.
The data suggests that the drone collided with something, but it was 387 feet up!
The data indicates that the drone pitched back 90 degrees and rolled upside down.
It recovered within a second, but the data shows no loss of altitude.
Something's not right there and some of the data can't be correct.
GPS issues would not explain this.
 
Joined
Jun 24, 2015
Messages
1,459
Reaction score
556
Age
73
Location
Arroyo Grande, California
I sent the wrong flight log that one is for my standard sorry I sent a second its here:
DJI Flight Log Viewer - PhantomHelp.com this one shows some weird stuff from my P3A.
I don't see a a problem with the P3S but the P3A definitely has a problem. As @Meta4 observed bad GPS data isn't the cause. A problem with either the gyro or accelerometer data is the likely culprit. To see that data we'll need to have the .DAT from the P3A. Look here to see how to retrieve the .DAT from the P3A. The .DAT you want is FLY148.DAT. It will be too large to attach to a post so you will need to use a public sharing site such as Dopbox or GoogleDrive.
 
  • Like
Reactions: sircking
Joined
Jun 24, 2015
Messages
1,459
Reaction score
556
Age
73
Location
Arroyo Grande, California
Why did the P3s show downlink lost at 6m 5.4s?
Doesn't look to me like it actually did lose the downlink. Maybe it reported lost downlink because there were a couple of missed packets in the previous 0.5 secs. There is probably some threshold expressed in number of dropped packets per time interval.
1629657767280.png
 
Joined
Jul 2, 2021
Messages
27
Reaction score
0
Age
55
I don't see a a problem with the P3S but the P3A definitely has a problem. As @Meta4 observed bad GPS data isn't the cause. A problem with either the gyro or accelerometer data is the likely culprit. To see that data we'll need to have the .DAT from the P3A. Look here to see how to retrieve the .DAT from the P3A. The .DAT you want is FLY148.DAT. It will be too large to attach to a post so you will need to use a public sharing site such as Dopbox or GoogleDrive.
Budwalker,
I can do this but back at work, will try it tonight.
 
Joined
Jul 2, 2021
Messages
27
Reaction score
0
Age
55
The P3 Standard seems to have flown normally, but why is the indicated GPS Health showing as zero?
Unknown, the P3S flys great no problems experienced in flight. Only issue is the camera has issues linking to my phone within the house, I expect its my WiFi.
 
Joined
Jun 24, 2015
Messages
1,459
Reaction score
556
Age
73
Location
Arroyo Grande, California
Is there a difference between senced sats and locked sta?
I assume you are asking can a GPS receiver know a sat exists but not using it because of poor signal quality. I suspect the answer is yes but that's not really relevant here. OSD:gpsNum is the number sats that are being used.

You may be asking what OSD:gpsLevel is. It's not a measure of sat signal strength. Nor is it related to the Dilution of Precision for the current GPS sat constellation. OSD:gpsLevel represents the confidence in the location data that is being computed from GPS, accelerometer, gyro and magnetometer data. The OSD:gpsLevel range is [0, 5] with 0 being no confidence and 5 being the most confidence. Certainly a low sat count can cause low confidence. But, low confidence can also be caused by problematic accelerometer, gyro or magnetometer data. I think the latter is the case with your P3A.
 

Meta4

Moderator
Staff Member
Premium Pilot
Joined
Jan 8, 2014
Messages
14,901
Reaction score
8,904
Unknown, the P3S flys great no problems experienced in flight. Only issue is the camera has issues linking to my phone within the house, I expect its my WiFi.
Your standard is fine - Airdata showed misleading data
It's just the P3Adv with issues.
The issues are likely to be hardware problems rather than anything in your local environment.
 
  • Like
Reactions: sircking
Joined
Jul 2, 2021
Messages
27
Reaction score
0
Age
55
Your standard is fine - Airdata showed misleading data
It's just the P3Adv with issues.
The issues are likely to be hardware problems rather than anything in your local environment.
Thanks I might have a job coming up to film a horse for sale, hoping this weekend maybe, will use the P3S. It does a pretty good job. will do my best to the .DAT file tonight.
 
Joined
Jul 2, 2021
Messages
27
Reaction score
0
Age
55
META4, sorry to report this but I can't get my drone to connect to a PC. I have tried both my desktop and my MSI gaming laptop. It doesn't recognise it at all, no noise of connection nothing showing on screen.

I started the controller , then the Drone and then the DJI Go APP. I connected the drone to PC with USB cable from USB three connection to the front USB port on the drone, then went into the advanced menu, then clicked on enter flight data mode, hit ok but the computer didn't recognise it. Is there a USB driver that needs to be installed?

Crazy days this thing is really fighting me.

Peter(SIRCKING)
 
Last edited:
Joined
Jun 24, 2015
Messages
1,459
Reaction score
556
Age
73
Location
Arroyo Grande, California
META4, sorry to report this but I can't get my drone to connect to a PC. I have tried both my desktop and my MSI gaming laptop. It doesn't recognise it at all, no noise of connection nothing showing on screen.

I started the controller , then the Drone and then the DJI Go APP. I connected the drone to PC with USB cable from USB three connection to the front USB port on the drone, then went into the advanced menu, then clicked on enter flight data mode, hit ok but the computer didn't recognise it. Is there a USB driver that needs to be installed?

Crazy days this thing is really fighting me.

Peter(SIRCKING)
Just to be clear the PC doesn't "announce" with a pop-up that the P3A is connected. To see that it's connected look for an extra drive in the Windows File Manager.
 

Meta4

Moderator
Staff Member
Premium Pilot
Joined
Jan 8, 2014
Messages
14,901
Reaction score
8,904
Thanks I might have a job coming up to film a horse for sale, hoping this weekend maybe, will use the P3S. It does a pretty good job. .
Have you used the drone to shoot horses before?
I would think that it would be one of the worst ways to film a horse.
The wideangle lens means you have to get close to see much of the subject and many horses are very nervous about drones.
 
Joined
Jul 2, 2021
Messages
27
Reaction score
0
Age
55
Just to be clear the PC doesn't "announce" with a pop-up that the P3A is connected. To see that it's connected look for an extra drive in the Windows File Manager.
Yes that's correct, the computer doesn't "announce" and no extra drive letter domes up in windows explorer, I will take her apart again and check the USB plug connection to the board.
 

New Threads

Members online

Forum statistics

Threads
141,159
Messages
1,453,647
Members
102,980
Latest member
DK621