Hi everyone,

My P4 arrived today so decided a quick test flight after charging everything.

All was good......until I tried to fly it.

Straight off,  I had to upgrade the remote,  easy task and was done quite quick.

Then it checked the P4 and all was "up to date".  

So I calibrated the compass and took to the sky,  well by sky I mean about 100cm.

The first error, message displays "Downward Vision Sensor Calibration Error".  So after consulting the manual,  it seems that this is a factory set calibration and cannot be done by the user.

Then it decides that the P4 firmware does require an update so I follow the instructions,  connecting the tablet directly to the P4.  3 attempts later and all I get is "Unable to update please reset device and try later".

Then when I start it up it now says firmware is up to date.  Strange but I tried to fly........next error...."Unable to Fly".

I check the status and it tells me that the IMU is calibrating.  It takes a few minutes to do this.

It now does this on every start up.  Surely it's not right that it takes this long?

So,  anyway,  eventually I get "Safe to fly".  Yippee!

I take off,  rise to about 100cm and "Downward Vision Sensor Calibration Error".  The unit doesn't really hover very well either and is quite scary as I feel totally out of control.

I then notice that the obstacle sensor is stating about 7m to the fence in the garden,  but it's more like 4m.

So,  I decide to connect it  to DJI Assistant 2. Straight away it tells me to upgrade the firmware as it's out of date!?  Make your mind up!

While it's in there I decide to perform a front Vision Sensor Calibration.  I try but the button is greyed out with a constant spinning wait icon next to it,  so give up.

Now with the updated firmware,  I try a flight.

Power up and it goes through the "Unable to fly",  IMU calibrating again for a few minutes.  I also notice that if I walk anywhere the P4 it loses its GPS signal.

As it's had a new firmware,  I carry out another Compass Calibration

So,  I take off........this time no message about the Vision calibration,  however,  it just doesn't feel very well controlled.  It won't hover in place and when moving around it does odd things.

For instance,  if I pan left and then back right,  it ascends about 5 inches. General stability feels terrible and actually pretty scary that at any moment it's going to just do its own thing.

I had an appointment so had to leave it for a few hours.  In the meantime I send off an email to the European Support.  I wanted to phone them,  but of course,  no European telephone number exists!

I had an email back in about 2 hours hoping they'd help,  but no,  it's just an email stating that if I want to send it back,  they will evaluate if I'm entitled to a replacement.  No offer of assistance or any details.

Back home and I decide to give it another try.  Bear in mind that it's been stored inside my house and it's been a nice warm spring day today,  I was surprised at the next message.....

So,  I power up,  again calibrate the Compass and go for a flight........well not quite.

"Unable to fly"

Check the status and this is a new message......."Battery too cold please warm up to 15deg Celsius"

How the hell did they do the Animal Rescue adverts in the snow?

So,  I remove the battery and put it back in,  power up.

"Unable to fly"

As you can imagine,  I'm starting to get a bit annoyed now!

Check the status and yet another new message....."IMU warming up".

It takes about 4 minutes to do this and I finally get a "Safe to Fly".  Yes!

Take off........ Scary and very dangerous.  The controls are just the same as earlier.  The P4 is all over the place doesn't hold its vertical or horizontal position and makes sudden movements in any direction upto a couple of inches at a time.

So I land it back down and it takes about 10 seconds to realise it's on the ground with it still trying to go back up and almost tipping over before shutting down the motors.

Just to confirm,  all these flights are in P mode.

I had no such issues flying my Phantom 3, it's not like I'm a newcomer as I've been flying for a while now.

It would be interesting to hear if anyone else is getting any of these issues.

After waiting since being able to place a pre-order,  I'm very disappointed and if I replace it will have to wait around another week for it to be inspected and (possibly) replaced.

I'm going to take it back out for another test tomorrow but suspect this one is going back to DJI.  What I don't want to do is send it back and the replacement has the same issues.

So as you can guess,  after having a great experience with my P3,  I'm disappointed and angry with the P4.

I'll keep this thread updated.

Wow that was a long read! That really sucks

You should give it one more try with all the gizmos turn off and lift off in ATTI mode.  If it flies OK it would mean the IMU is working correctly.

Uninstall and re install the DJI go app.

Hi

Set my new P4 up today flys real well stable hover no trouble.

Firmware needed updating in the controller plus P4 first, then a full IMU cal was done last thing a my fly site was a compass cal

I would take your time read the update tread from DJI then do a full IMU cal sounds to me it just not calibrated correctly!

Thanks for all the replies.  I have manually calibrated the IMU. That's one thing I missed in my post.  I will try and make the time tomorrow to start a fresh.  I will default everything and reinstall Go.  But for me it seems there has been too many different errors to be just the IMU.  As I mentioned,  the firmware is now the latest as it was done my Assistant2 rather than the failed attempts of Go.

From the bottom of my heart I sincerely thank you for being an early adopter.  If I were faced with that frustration,  I would find out where the Dji guys lived and I would go to thier house and scatter their garbage all over the place.  Then I would release 5 ground squirrels on their property.  And laugh.  Bwahahaha.
Thanks again.  Really.

Sorry to hear about your troubles, but as others  have stated, this is a good example of why I'm not an early adopter of tech items like this...  Good Luck!

Hi, Downward Vision Sensor Calibration Error means you need to calibrate it by the software. About the battery and IMU warming, what is the environment temperature? If it's too cold, you need to hover the aircraft and warm the battery, then you can be able to fly. I think the IMU module might have a hardware problem. Please provide a screenshot of the IMU info and the firmware version(setting->about). At the same time, try to power on the aircraft and start the IMU calibration ASAP after the self check of the gimbal finished.  Try to calibrate the vision sensor by the assistant software one more time.

Thanks for replying.  Regarding hovering to warm it,  that's not possible as it won't fly due to being too cold.  I will try to calibrate both the IMU and vision sensor again and let you know.  I will also get a screenshot as requested.

Hi Craig
Few things more frustrating than not being able to play with a new toy properly due to updates and calibration errors.

Can I ask how cold your area is?  We've not had much below 5'C lately in the UK; were you storing the drone in the house or the garage?  Keep it in the house for a few hours, calibrate the IMU and the compass away from anything metal including your mobile, out in the garden.
Finally, try hovering at least 2-3 metres high if not more, and in an open space like a field rather than near any obstacles. See if it gets its senses together a bit more after a simple flight.
Sorry I can't offer more help; especially as I'm a lowly P3S owner   but I'm just throwing some ideas based on what you wrote.

Good luck and hope you get it sorted
Ian

Thanks Ian,  it was in a warm house then taken outside where it was just below 10deg. When I took the battery out after the cold warning,  it was warm to touch so warmer than the 15deg it was asking for.  I plan on getting it out in an open area later to see what happens as even though I have a large garden with lots of space I was nervous to take it up.  Error after error (each one being different)  is leading me to think it has a hardware issue.  As I mentioned,  flying my P3 in similar circumstances never had any issue.

Hi

I alway do a cold IMU cal so it can see a range of temps as it heats up.
Leave it out somewhere to get as cold as it can but keep the battery inside, then get ready bring it in start it up it say IMU warming but go straight to the cal page and let it do its stuff, seems to work better that way

Could try that

Cheers Mark,

I'll give that a go too.
Of course, it doesn't help calibrating the Vision System as Assistant2 doesn't work.

Craig, really feel sorry for all this story...I am a happy P3P user and my empathy  with all this problems in your the new P4 makes feel disgusted.  I hope this is an extraordinary quality problem, one in hundred, defect units being delivered and sold.  I will follow this tread . Please let us know how it is finally solved! Take it easy!

microcyb Posted at 2016-3-17 07:13
Uninstall and re install the DJI go app.

Yeah verily.  I could not get the latest firmware until I UNINSTALLED and reinstalled the DJI GO app, even though it was updated to 2.7.

Yeah, when I get home later (provding I'm home in time for good light), I will be starting from the beginning.  I will reset all settings to default, re-install GO, calibrate the IMU, recalibrate the Compass and try to recalibrate the Vision Positioning (if Assistant2 works).

I'll let you know how I get on.

Maybe try a different location to fly in

  When you do the IMU calibration make sure surface is perfectly level, check with a level and adjust as necessary.  After calibration  starts stay away for at least 10 minutes because even the floor vibration can affect proper calibration of the aircraft.  When doing compass calibration do it in a wide open field away from ANY METAL,  make sure transmitter is at least 15 feet away as well, no wrist watch or change in pocket as well,  keep in mind that concrete sometimes has metal" re bar " in it, so a open field is your best bet.    Once you set these there is no need to keep repeating.  Only if you travel more than 100 miles from the calibration site or after a hard landing or firmware update is it really necessary.  Do it once and do it properly.  

All the best to you and yours- donnie

You may have noticed, I've changed the title!

First, thanks to everyone who replied with valuable information.  So, all is now good and I've been out for a great fly in the late golden hour of sunset.

So what did I do?

Well, I reset everything and also removed and updated the Go app.  What fixed it????  I don't know.....

So, first I uninstalled Go and reinstalled, then I performed a IMU calibration on the same flat surface I did yesterday followed by a compass calibration before taking off.

Then put her (it's now a her) in the air and it's perfect.   Totally stable, fully controllable and a joy to fly.   I also tested out the vision system and it is now bang on the money detecting obstacles.

No sign of any of the strange errors I was getting yesterday and spent two batteries flying around the farmland near to the house.  I can also say that I can instantly tell the difference between the quality of the lens over my P3 Pro.

So, what was it that fixed it?   I'm pretty sure it was the app as suggested by some, this is the only thing that has changed as both calibrations where done in the same place they were done yesterday.

I'm still annoyed at the lack of support from the European Support group at DJI though.  Instead of offering any advice their answer was simply "send it back" and then they closed their support ticket..........That's still not good support.

Final parting smile........

I brought her indoors and powered it up and the compass was recieving interference.  Spot the spelling mistake!

Sphellin

Craig Rogers Posted at 2016-3-18 02:07
You may have noticed, I've changed the title!

First, thanks to everyone who replied with valuable i ...

Maybe yours has been knighted...LOL...Only appropriate as you are in the UK...happy flying...."Sircraft"....

Craig Rogers Posted at 2016-3-17 14:07
You may have noticed, I've changed the title!

First, thanks to everyone who replied with valuable i ...

Glad you are working now.
The main clue that told me you needed to uninstall and reinstall the DJI Go app was you said
" had no such issues flying my Phantom 3, "

So data was cached (stored) on your mobile device and was confused within the app revision changes (just an app update would not work).

I have the same problem