So, I have a Phantom 2 v2.0 that's acting a little weird compared to Phantoms I've owned in the past.

Upon startup, pretty much every time, it gives me the long red/yellow alternating, which means it wants a compass calibration.

When you do a compass calibration, do the Naza dance, then it goes to a fast red blink.

You can actually fire it up and take off in this state and it goes to a normal green blinking "GPS" mode indicator.

Is there something wrong with this thing?

Edit: edited to correctly show "compass" calibration, rather than GPS

After compass calibration you will get a green flash then a series of red flashes which is normal for Naza mode.

Justin the others are correct. If you get flashing from red then yellow you either need compass calibration or compass calibration failed. Once you get a good compass calibration you should see yellow then green with longer flashes of each instead of quick flashes. During coass calibration don't have any ferious metal close by. DJI even says no cell phones or even car keys as that can throw the compass off during calibration.

if it's just fast red flashes you're near a no-fly zone.

Yeah, I meant the compass calibration... doing too many things at once.

I think this is the no-fly zone. Failed compass calibration should just go back to red/yellow slow flash, if I remember correctly.

justin.bregar, you're right. The Phantom manual says a failed compass calibration will result in red/yellow flashes.

Here are DJI's no fly zones:
http://www.dji.com/fly-safe/category-mc

I'm not sure that list of no-flys is comprehensive.

The spot where I was doing testing the other day is near a small airport, but it's not listed on the DJI list there. Another spot where I've seen a different P2 (v1.0) do the same thing recently was a soccer field near what's essentially a state prison.

Interestingly, the P2 will still take off and fly just fine... even returning to normal LED operation after taking off.

justin.bregar Posted at 2015-5-18 22:35
I'm not sure that list of no-flys is comprehensive.

The spot where I was doing testing the other da ...

i think the red flashing you saw is when not all 6 satellites are locked yet, in naza mode, 1 green, 3 red; then 1 green 2 red; then 1 green 1 red; at the end, only green... this is the procedure of locking more and more (from less than 5 to over 6 satellites). you just caught that in action. I saw those red lights in my p2v as well. no issue.

This isn't that. This is a very rapid red blinking. No alternating with green at all.

justin.bregar Posted at 2015-5-20 12:50
This isn't that. This is a very rapid red blinking. No alternating with green at all.

Hello Justin,

Do you have already found the solution or reason for the compass error RED LED?


Following your threat...
Same compass issue with my P2 after software upgrade.
DJI did a mistake by upgrading the IMU to 3.14 under an old DJI Assistand version 3.6 in steat a of 3.8.
Anyway, I did already all other recommendations I found on the web.
Alike,  install assist soft 3.8, a hard reset the P2,, install the new software 3.14 , calibration of thE IMU.
(As in fact calibration wasn't necessary because all values were OK)
At the end , calibration end up in RED LED  flashing.

If you are getting a solid series of red flashes after calibration then something is not right. You may want to try an advanced IMU calibration on a perfectly level surface without disturbing the Phantom during the process.  Also, you may have a bad battery. Try another battery if you have one.
Once compass calibration is complete, you will get one green flash (indicating the Phantom is in GPS mode, then red flashes indicating Satellite status.  

I successfully flew my phantom 2 for the first time in January (in Phantom mode, not Naza) after calibrating it as per all the instructions.  After that I put it into NAZA mode with the same software.  Yesterday, I was ready to once again fly but have been unable to calibrate the compass on its vertical axis.   The first attempt yielded a flashing of 1 green and then 3 blinking red.  At the time I didn't remember that these flashing colours were linked to its being in NAZA mode as was expecting the LEDs to turn off as per the instructions for successful calibration when it's in Phantom mode.  So plugged the Phantom into the Assistant and changed it back to Phantom mode.  It appears to calibrate fine on its horizontal axis as the LEDs go from yellow to green but the clockwise spin on the vertical axis results in the LEDs either returning to flashing yellow or fast red flashing, as opposed to turning off.  

Today I have tried advanced IMU calibration with the Assistant software both in Phantom and NAZA modes and still no luck.  (And to complicate matters, the advanced calibration has been returning a message that the temperature of the MC is too hot and to turn off for 15 mins to let it cool down and try again, which I did but still no luck.  Based on what I've read on the net, this temperature warning is some glitch in the software and one should simply click through and let the calibration continue. I have done that as well).

My Compass Mod value during the advanced calibration was 1272 in Phantom mode and moved up to 1315 when in NAZA mode.  The info in the Assistant says the normal range is between -500 - 500.  I'd be grateful for feedback on this.

Needless to say, the Phantom's compass is still NOT calibrating on the vertical axis despite following all the IMU calibrating instructions.  Could a problem with the GPS in the unit be the cause?  Or do I need to go try the whole magnet process I see discussed in some fora?

Any help would be GREATLY appreciated.  And I'm hoping the DJI folks will come forward with help too please

Jo2014 Posted at 2015-6-5 10:31
I successfully flew my phantom 2 for the first time in January (in Phantom mode, not Naza) after cal ...

Jo,
When doing the advanced calibration, I use a bubble level across the top of the motor spindles and shim up the legs to get the Phantom level. Once level I perform the advanced calibration and ensure the Phantom is perfectly still while it is calibrating. Most people ignore the high temperature warning and I have as well. If you power it up and don't waste too much time to start the calibration I believe it is ok to ignore the warning. I have also heard of putting their Phantoms in the refrigerator for a brief time prior to a calibration.
As far as the compass calibration, I have a post I created as to what the normal sequence of LEDs should be displayed after successful calibration and I still do not have a definitive answer. mine, when I complete the vertical rotation I get 3 Red flashes, then a long series (2 or 3 seconds) of green flashes, then it goes into the GPS/Satellite status mode. Prior to updating to 3.14 I used to get 1 red flash, then the long series of green before going into the GPS/Satellite mode.

Raybro Posted at 2015-6-5 22:38
Jo,
When doing the advanced calibration, I use a bubble level across the top of the motor spindles  ...

Thanks Raybro.  I just read your LED sequence post.  I can't recall if on Wednesday when I first tried to calibrate I got the long series of green flashes before it went to 1 green then red/red/red.

I've posted my issue in the help section, with my queries clearly identified this time so am hoping there will be more feedback.

I will not fly it unless the compass can calibrate.

Jo2014 Posted at 2015-6-5 22:50
Thanks Raybro.  I just read your LED sequence post.  I can't recall if on Wednesday when I first t ...

Another thing I have noticed since I updated to 3.14. I never had indication of a compass failure with the alternating yellow red flashes after the vertical rotation. Ok, since the update I have gotten on occasion the continuous red flashes after the vertical rotation which tells me it failed.

I ended up returning mine to the retailer that sold it to me.

justin.bregar Posted at 2015-5-19 20:50
This isn't that. This is a very rapid red blinking. No alternating with green at all.

Sir!!! Please help me I have the same problem at the end of compass calibration it starts blinking red . Please help me sir

Jo2014 Posted at 2015-6-4 18:31
I successfully flew my phantom 2 for the first time in January (in Phantom mode, not Naza) after calibrating it as per all the instructions.  After that I put it into NAZA mode with the same software.  Yesterday, I was ready to once again fly but have been unable to calibrate the compass on its vertical axis.   The first attempt yielded a flashing of 1 green and then 3 blinking red.  At the time I didn't remember that these flashing colours were linked to its being in NAZA mode as was expecting the LEDs to turn off as per the instructions for successful calibration when it's in Phantom mode.  So plugged the Phantom into the Assistant and changed it back to Phantom mode.  It appears to calibrate fine on its horizontal axis as the LEDs go from yellow to green but the clockwise spin on the vertical axis results in the LEDs either returning to flashing yellow or fast red flashing, as opposed to turning off.  

Today I have tried advanced IMU calibration with the Assistant software both in Phantom and NAZA modes and still no luck.  (And to complicate matters, the advanced calibration has been returning a message that the temperature of the MC is too hot and to turn off for 15 mins to let it cool down and try again, which I did but still no luck.  Based on what I've read on the net, this temperature warning is some glitch in the software and one should simply click through and let the calibration continue. I have done that as well).

Sir!!! Did you find the solution ??

Raybro Posted at 2015-6-5 07:06
Another thing I have noticed since I updated to 3.14. I never had indication of a compass failure with the alternating yellow red flashes after the vertical rotation. Ok, since the update I have gotten on occasion the continuous red flashes after the vertical rotation which tells me it failed.

Sir!!! I have also the same problem of getting red blinking light at the end of compass calibration.

What drone do you have?  If a P2, are you in Phantom mode or Naza mode?  Is there any green mixed up with the red?  A video showing your drone would be ideal.