Unstable: GPS Woes

Braccodog · Apr 21, 2016

I just got my Phantom 2 back from DJI who replaced the 2.4 receiver. I can't calibrate: keep getting yellow flashes. When connected to the Assistant, it will not show "GPS Mode", but defaults to "Normal Flying". Now when I switch to Naza Mode, I get one green + three red flashes when calibrating, and when connected to the Assistant, it will show GPS Mode.

Whatever it's doing, the thing is very unstable and will drift in almost every direction (yaw, pitch, altitude).
I am very new to this, but have read the manual thoroughly, read a lot of forums, and I'm impatient.

Any help is much appreciated.

Martyn · Apr 22, 2016

When you try to calibrate the compass are you indoors or in the middle of a field ?

Braccodog · Apr 22, 2016

Thanks Martyn...I'm not in the middle of an open field, but in my neighborhood (in my yard)

Martyn · Apr 22, 2016

Braccodog said:
Thanks Martyn...I'm not in the middle of an open field, but in my neighborhood (in my yard)

You must make sure that you are well away from any of the following: Mobile phones, bunches of keys, magnetic objects or large metal structures above or below ground. The thing to bear in mind is that you may have metal supports under the ground you are standing on, in your backyard.
The best place for calibration is in the middle of a field, well away from the above mentioned.
This should cure your problem.
Let us know how you get on ?

AzDroner · Apr 26, 2016

Pop the top and make sure the GPS plug is connected, one green and 3 red means you have less than 5 satellites. Nothing to do with calibration.
http://www.phantompilots.com/attachments/web-naza-m-jpg.1060/

Braccodog · Apr 26, 2016

Thanks very much...i just got a new 4mm part for the GPS which I am going to install....hopefully that will help too

N017RW · Apr 26, 2016

I have calibrated my P2 compass 3 times in two years. All in my suburban yard with reinforced concrete driveway.

Mako79 · Apr 26, 2016

Braccodog said:
Thanks very much...i just got a new 4mm part for the GPS which I am going to install....hopefully that will help too

Is your phantom a vision series?
Can you connect to your app?
You just need to go to an open field and wait for the green lights or sat counts >6 on your app. While you are in an open field, do a compass dance to reprime the compass.

Also, if you are upgrading your GPS, consider using a larger thick compass like this:
http://taoglas.com/images/product_images/original_images/CGGBP.35.6.A.02.pdf
Its over kill, but you can upgrade your compass to the below and add the CGGBP.35.6.A.02 puck in the future in case your damage your board.
Ublox M8N GPS Compatible with DJI NAZA Lite V2 Flight Controller TXWD
The puck is a 6mm thick 35x35 ceramic that can withstand a few crashes. It also picks up all current GPS and Glonass and future proofs for the chinese and the brits sats aswell. This will possibly give you more than 16 sats (GPS+Glonass).
I don't have evidence that it will work but I will consider this if my compass goes bananas.

Mark The Droner · Apr 28, 2016

I kinda doubt it would work. I've never heard of a P2 getting GLONASS. The listing says it SUPPORTS a compass, it doesn't say it includes a compass. Finally, it doesn't ship to the U.S.

The OP should read the manual cover to cover at least twice.

He cannot calibrate (his compass apparently). That's a big problem. If I was the OP, I would start from scratch, update all the firmware one by one. Calibrate the compass. And then try it out and see what's up. If it still isn't right, calibrate the IMU and give it another go.