Vision 2 Plus GPS issues revealed

[singapore_phantom]

For the record, I took my NAVI GT31 GPS to my flying spot to compare sat reception between its GPS receiver and that of the Phantom.

The GT31 showed "In view 12" and "Tracking 9". My Phantom never showed less than double digits, at one point showing 15 sats! This is one higher than the max according to http://satpredictor.navcomtech.com/ but that's probably because the copter was higher than the 10 meters default of http://satpredictor.navcomtech.com/

All in all, my (for now, cautious) conclusion is that the GPS mod is not required, at least not on my Phantom, which is the P2 Vision Plus. But I'll take out the GT31 every time from now on to get a more significant average.

 

[CapnBob]

Funny you should say that. I live in MA, and this just happened in Cambridge. When he saw the hawk coming in, he throttled down, as to not hurt it. I still don't see how the hawk didn't get injured attacking from above. My drone attacked me a few months ago and made mincemeat out of my hand.

https://www.youtube.com/watch?v=AhDG_WBIQgc

 

[ado]

When using naza-m, the home point lock is when the phantom flashes 8 or sometihing fast green lights yes? If so, my phantom usually sets home point when inside but it has 0 sats. It blinks 3 red and one green indicating it has no or low sats, and on app it shows 0 sats, but it suddenly after a minute or 2 starts flashing fast green lights like it set a home point, how can it do that with no sats?

When it was brand new it always had more or less then 6 sats indoors. Maybe a month ago i changed to naza-m mode, and i dont know what happend but ever since i changed to naza it registers 0 sats most of the time. It happend maybe 2 times that it registered 4-5 sats.

Its like naza-m made the GPS weaker.
Ive got 13 sats in naza-m one time but not until i gain some alltitude (not much). before take off it had 8. I was flying with 9-10 sats, after some minutes it got 12-13. It stays on 10 sats basicly every fly.
When i flew it in Phantom mode, it pretty much always had 10 sats on ground maybe even more, and in air it was rocking 12-13 sats with stability.

 

[Fplvert]

Gps issues seem to vary as other signal defiencancies.
viewtopic.php?f=4&t=11306&start=30
Nothing perfect in this world!

 

[BlackTracer]

When using naza-m, the home point lock is when the phantom flashes 8 or sometihing fast green lights yes? If so, my phantom usually sets home point when inside but it has 0 sats. It blinks 3 red and one green indicating it has no or low sats, and on app it shows 0 sats, but it suddenly after a minute or 2 starts flashing fast green lights like it set a home point, how can it do that with no sats?

When it was brand new it always had more or less then 6 sats indoors. Maybe a month ago i changed to naza-m mode, and i dont know what happend but ever since i changed to naza it registers 0 sats most of the time. It happend maybe 2 times that it registered 4-5 sats.

Its like naza-m made the GPS weaker.
Ive got 13 sats in naza-m one time but not until i gain some alltitude (not much). before take off it had 8. I was flying with 9-10 sats, after some minutes it got 12-13. It stays on 10 sats basicly every fly.
When i flew it in Phantom mode, it pretty much always had 10 sats on ground maybe even more, and in air it was rocking 12-13 sats with stability.

That is course direction being set not home point. Home point is the second set of greens after 6 or more sats are locked.

 

[ado]

[/quote]
That is course direction being set not home point. Home point is the second set of greens after 6 or more sats are locked.[/quote]


It is home lock acording to the naza-m led lights picture at the bottom of this site.

http://www.pattayadays.com/2014/03/naza ... -2-vision/

 

[Panamon Creel]

First set of fast blinking green leds is for forward direction/orientation recording and happens approx. 30 seconds after the Phantom has been powered up or if manual orientation recording was done via the S2 switch. Recording for Home point happens after that when 6+ Sats had been locked onto which is also acknowledged by fast blinking green leds.

 

[N017RW]

First set of fast blinking green leds is for forward direction/orientation recording and happens approx. 30 seconds after the Phantom has been powered up or if manual orientation recording was done via the S2 switch. Recording for Home point happens after that when 6+ Sats had been locked onto which is also acknowledged by fast blinking green leds.

This may sound like splitting hairs but I believe it has been proven that the [exact] home point (HP) is stored/recorded upon motor start and not the location or time at which the second rapid green flash pattern occurs.

To test this a poster relocated the aircraft several meters, to exceed possible GPS error or accuracy effects, between the location that the second rapid light pattern occurred and actual take-off then tested the return location via a RTH execution.

 

[Panamon Creel]

....To test this a poster relocated the aircraft several meters, to exceed possible GPS error or accuracy effects, between the location that the second rapid light pattern occurred and actual take-off then tested the return location via a RTH execution.

could be possible but I'll hold my judgement on that until I made the test myself

 

[N017RW]

In the meanwhile, if you wish, you can review this document which describes it...

http://wiki.dji.com/en/index.php/Naza-M ... on_Control

It's in the table below the heading:"Method of Forward Direction and Home Point Recording".

 

[Panamon Creel]

In the meanwhile, if you wish, you can review this document which describes it...

http://wiki.dji.com/en/index.php/Naza-M ... on_Control

It's in the table below the heading:"Method of Forward Direction and Home Point Recording".

It would make sense to reset the Homepoint if the unit was moved after power-up since that's the actual take off-position but it still should acknowledge the manual recording at motor power-up with fast blinking green Leds. I usually power-up and take off at the same spot so dunno

 

[N017RW]

In the meanwhile, if you wish, you can review this document which describes it...

http://wiki.dji.com/en/index.php/Naza-M ... on_Control

It's in the table below the heading:"Method of Forward Direction and Home Point Recording".

It would make sense to reset the Homepoint if the unit was moved after power-up since that's the actual take off-position but it still should acknowledge the manual recording at motor power-up with fast blinking green Leds. I usually power-up and take off at the same spot so dunno

I do the same with regards to PU and TO.

However I have never heard anything to contradict what I have posted ar read in DJI's Wiki pages.

It seems the second group of flashes is to affirm GPS data meets DJI's criterion, nothing more.

 

[morph000]

Interesing if one considers only 4 satellites are really needed:
http://geospatialrevolution.psu.edu/edu ... ation.html

Even with 4 you'd be getting close enough to home point to regain control

On a side note - the Vision2+ gets 6 sat lock in around 10 seconds (almost as fast as the phone) outside but even when the wifi is up, it seems to take a few minutes for the # of satellites to show up on the phone (Samsung Note 2).
ie large lagtime in relaying that info.
Anyone noticed that too?

 

[Panamon Creel]

I do the same with regards to PU and TO.

However I have never heard anything to contradict what I have posted ar read in DJI's Wiki pages.

It seems the second group of flashes is to affirm GPS data meets DJI's criterion, nothing more.

Well the Wiki also says "The LED will blink Green quickly if successfully recorded"

Anyways so I did the test. After power-up and once the second set of fast blinking green Leds occurred the Home point is acquired and shows up on the map of the App, however the Homepoint is not yet locked so if you move around the Homepoint will move around on the Map wherever you go with your Phantom. Homepoint gets locked as soon as you start the motors (not acknowledged by green LED flashes) or if you manually record Homepoint via the S2 switch (Green Leds flash)
Test done while in GPS-Atti, Atti and Manual mode and all behave the same in that regard.

I guess the Wiki could use some improvements.
Personally I wouldn't call an automatic Homepoint lock with motor start a manual method and a manual toggle of the S2 switch an automatic method

Edit to add: The latest manual for the Naza-M V2 shows it correctly with Manual and Automatic row labels interchanged