Hello, after the dreaded please reboot aircraft error while trying to calibrate the VPS, I finally managed to calibrate succesfully. After calibration succesful, I get this screen:
And the message "Calibration complete. Calibration success. Restart aircraft"
I turn the P4 off (press press and hold method on the battery button), and when I turn back on I get the error on the DJI Assistant 2 For Phantom "Connection with aircraft Lost please calibrate again"
I tried everything! Leaving the cable on after restarting, restarting with the cable off and plugging it in again
still no dice! I get no grid on the app when I connect my phone to the controller, but also I get no VPS system errors. What seems to be the case? I have calibrated about 5 times already and nothing happens! It "succesfully calibrates" but it seems to do nothing! I bought this P4 a few days ago and I had no vps grid on the app to begin with, and no VPS errors either and thought the calibration would bring it back. I was mistaken.
What can I do? I have tried running the software with admin privileges, still no dice!
Windows 7 64bit Pro

Phantom 4
DJI Assistant 2 for Phantom v2.0.6
Please help guys, I never use the front vps anyway because I always fly line of sight and far away from obstructions but its nice to know that it actually works, plus right now I cannot do precision take off and the bottom sensors too are not being used, even after the so called "succesful calibration"!!!!

I get no grid on the app when I connect my phone to the controller ...
I bought this P4 a few days ago and I had no vps grid on the app to begin with
What VPS grid?
There is no VPS grid.

I never use the front vps anyway
You mean Obstacle Avoidance.
VPS = Vertical Positioning System and there is no "front VPS".

I cannot do precision take off and the bottom sensors too are not being used, even after the so called "succesful calibration"!!!!
How about turning on your sensors.
It sounds like you have the OA/VPS sensors disabled in your app settings.

Labroides Posted at 3-5 20:13
I get no grid on the app when I connect my phone to the controller ...
I bought this P4 a few days ago and I had no vps grid on the app to begin with
What VPS grid?

Thank you for the quick reply! I meant the vision positioning system, i guess we mean the same thing but I referred to it the wrong way. Sensors are all enabled in dji go4
I dont get the grid pattern that shows you how far or close you are to an obstacle.
also I dont have "precision take off" as an option when auto taking off
double checked, all my obstacle sensors are enabled in dji go4
Also, no errors while starting up and flying
the front sensors and botttom sensors do work and are not damaged or blocked, since during the calibration I am able to see what they see in the little preview boxes.
Shall I try an older version or on another pc?

georgios87 Posted at 3-5 20:20
Thank you for the quick reply! I meant the vision positioning system, i guess we mean the same thing but I referred to it the wrong way. Sensors are all enabled in dji go4
I dont get the grid pattern that shows you how far or close you are to an obstacle.
also I dont have "precision take off" as an option when auto taking off

ok just checked I am still referring to it the wrong way. VPS does indeed mean vertical positioning system, there is no vison positioning system

Anyway I shall refer to it the correct way now, front obstacle sensors and bottom obstacle/positioning sensors? correct?

georgios87 Posted at 3-5 20:23
ok just checked I am still referring to it the wrong way. VPS does indeed mean vertical positioning system, there is no vison positioning system

Anyway I shall refer to it the correct way now, front obstacle sensors and bottom obstacle/positioning sensors? correct?

Tap the icon between GPS & RC Signal icons on the top of the app screen and you can enable the sensors.

Labroides Posted at 3-5 20:45
Tap the icon between GPS & RC Signal icons on the top of the app screen and you can enable the sensors.

Thank you once again.
Vision sensors, as I said before, are enabled. All of them, both the bottom ones and front ones, I have enabled all of the options in that menu. I disabled and re-enabled them, still no luck. I will include a screenshot asap to prove to you that they are indeed enabled.

georgios87 Posted at 3-5 20:47
Thank you once again.
Vision sensors, as I said before, are enabled. All of them, both the bottom ones and front ones, I have enabled all of the options in that menu. I disabled and re-enabled them, still no luck. I will include a screenshot asap to prove to you that they are indeed enabled.

I am thinking a fw update would fix this, so this would be my last resort

It should be your 1st resort ;) always fly up to date unless known issues  with the latest, there isnt at this time and its been a good few months now ;)

Bashy Posted at 3-5 20:53
It should be your 1st resort ;) always fly up to date unless known issues  with the latest, there isnt at this time and its been a good few months now ;)

Thank you very much! I will update fw and keep you posted on what happened! Thanks to both of you for the quick responses
Best regards!

georgios87 Posted at 3-5 20:48
I am thinking a fw update would fix this, so this would be my last resort

Fix what?
You haven't said anything that suggests there is a problem with the drone.

Labroides Posted at 3-5 23:11
Fix what?
You haven't said anything that suggests there is a problem with the drone.

Yes I am terribly sorry for not being clear.
The problem is that even though the vision sensors appear to be working (I get preview image/video during the calibration in the windows software) and the calibration is successful, upon aircraft restart the calibration is not being saved. No precision landing is available (a clear sign that the bottom sensors are not being used) and the radar chart is nowhere to be seen even though the sensors (and radar chart) are enabled in the vision sensor settings in the dji go 4 app being used to fly the drone in conjuction with the remote

georgios87 Posted at 3-6 01:47
Yes I am terribly sorry for not being clear.
The problem is that even though the vision sensors appear to be working (I get preview image/video during the calibration in the windows software) and the calibration is successful, upon aircraft restart the calibration is not being saved. No precision landing is available (a clear sign that the bottom sensors are not being used) and the radar chart is nowhere to be seen even though the sensors (and radar chart) are enabled in the vision sensor settings in the dji go 4 app being used to fly the drone in conjuction with the remote

Nothing sounds like there is any real problem.
Much of what you've said suggests strongly that you are inexperienced and confused.
There is no such thing as a VPS grid, having live view and radar display are completely unrelated to VPS.
It sounds like you simply haven't enabled the OA/VPS sensors in your app settings.

Go into the app and turn them on.
Here's what you are looking for:

Labroides Posted at 3-6 03:38
Nothing sounds like there is any real problem.
Much of what you've said suggests strongly that you are inexperienced and confused.
There is no such thing as a VPS grid, having live view and radar display are completely unrelated to VPS.

THEY ARE ON!!!!!!!!!!!!!!!!!!!!
HOW DO YOU NOT UNDERSTAND THAT???
If you keep up with this behavior I will be 100% sure you are trolling me.
Ok since you are soooooo experienced, you would know what a radar chart is its RIGHT THERE on the screenshot you uploaded. ITS CALLED A RADAR CHART and it doesnt show in my app when I fly even though all sensors are on. You can take your experienced self over to this link and see it performing live

also it is so weird that you, being so experienced, do not know the difference between the in-app radar which just shows you where the craft is in relation to where you are looking at, and the obstacle avoidance radar CHART!!!!!

I will just sit my inexperienced and confused butt here (built several racequads, naza v2 quads, professional topography A2 octacopter, mavic pro owner, phantom 3 owner) and laugh at you because you are either definately trolling me, or too much experience has blurried your insight on what others are clearly saying to you!

georgios87 Posted at 3-6 03:47
THEY ARE ON!!!!!!!!!!!!!!!!!!!!
HOW DO YOU NOT UNDERSTAND THAT???
If you keep up with this behavior I will be 100% sure you are trolling me.

THEY ARE ON!!!!!!!!!!!!!!!!!!!!
HOW DO YOU NOT UNDERSTAND THAT???
Maybe because up till now you've never said that the sensors were enabled although I'ver been trying to coax it out of you.
it is so weird that you, being so experienced, do not know the difference between the in-app radar which just shows you where the craft is in relation to where you are looking at, and the obstacle avoidance radar CHART!!!!!
Because the alternative to the map view is called the radar display and no-one calls the OA display the radar anything.
But you're so new to the P4 series you wouldn't know that.

I'm done.  Sorry I wasted any effort with you.
I prefer dealing with people that give relevant information and don't have a snarky attitude.
Good luck

Labroides Posted at 3-6 04:31
THEY ARE ON!!!!!!!!!!!!!!!!!!!!
HOW DO YOU NOT UNDERSTAND THAT???
Maybe because up till now you've never said that the sensors were enabled although I'ver been trying to coax it out of you.

I LITERALLY mention in every answer to you that sensors are enabled... I dont see what you missed, I am sorry too

georgios87 Posted at 3-6 04:40
I LITERALLY mention in every answer to you that sensors are enabled... I dont see what you missed, I am sorry too

Which device are you using as a display, there may be some conflict with it and  DJI Go 4  not displaying things correctly.

Also after successful calibration I find it's best to restart Assistant 2 as well as aircraft, this should then display its current firmware level.

Aardvark Posted at 3-6 07:48
Which device are you using as a display, there may be some conflict with it and  DJI Go 4  not displaying things correctly.

Also after successful calibration I find it's best to restart Assistant 2 as well as aircraft, this should then display its current firmware level.

Thank you very much! I used an iPhone 6S and an iPad mini 2. Same in both, the radar chart or OA display as I understand from Labroides most people might refer to, never shows. Obstacle avoidance is enabled and all sensors and options enabled. Also, I get no system errors at all, regarding vision system or need for calibrating it but clearly from hover tests I have made the front or bottom sensors do indeed seem to be inactive. I even get the obstacle avoidance icon appearing as "white" and not greyed out as it would be if OA was off. I think its a lost cause trying to calibrate the sensors on this old P4 firmware I don't remember the exact version but I remember it says the firmware was last updated in June of last year!!! I will update the firmware as soon as I can access a pc again and I will keep you guys posted. Once again, I am sorry for lashing out at Labroides, but I really thought he was trolling me from a point on (anonymity of the internet and trying to make meaning of written text can cause misunderstandings of context many times), never meant to come out as a smug sob, I am the exact opposite and I am willing to learn more and more since I believe nobody is perfect. I must say that I tried all methods I describe above to fix the problem and exhausted all info I have found online on the matter or in written manuals or this and other forums before posting my problem here, the last thing I would want is to waste anybody's time with stuff that has been answered before. I believed I made myself pretty clear to him about having all sensors enabled but I guess because of the fact that I am not a native english speaker some of that probably got lost in the translation? anyhow, just wanted to clarify a few things since I am new in this forum and don't want to leave a bad impression

georgios87 Posted at 3-6 08:30
Thank you very much! I used an iPhone 6S and an iPad mini 2. Same in both, the radar chart or OA display as I understand from Labroides most people might refer to, never shows. Obstacle avoidance is enabled and all sensors and options enabled. Also, I get no system errors at all, regarding vision system or need for calibrating it but clearly from hover tests I have made the front or bottom sensors do indeed seem to be inactive. I even get the obstacle avoidance icon appearing as "white" and not greyed out as it would be if OA was off. I think its a lost cause trying to calibrate the sensors on this old P4 firmware I don't remember the exact version but I remember it says the firmware was last updated in June of last year!!! I will update the firmware as soon as I can access a pc again and I will keep you guys posted. Once again, I am sorry for lashing out at Labroides, but I really thought he was trolling me from a point on (anonymity of the internet and trying to make meaning of written text can cause misunderstandings of context many times), never meant to come out as a smug sob, I am the exact opposite and I am willing to learn more and more since I believe nobody is perfect. I must say that I tried all methods I describe above to fix the problem and exhausted all info I have found online on the matter or in written manuals or this and other forums before posting my problem here, the last thing I would want is to waste anybody's time with stuff that has been answered before. I believed I made myself pretty clear to him about having all sensors enabled but I guess because of the fact that I am not a native english speaker some of that probably got lost in the translation? anyhow, just wanted to clarify a few things since I am new in this forum and don't want to leave a bad impression

"I used an iPhone 6S"

I use an iPhone 6S plus with my P4, which displays the 'radar' for the front Obstacle Avoidance sensors.

Although this may sound obvious, check that the 'display radar chart' is enabled in DJI Go 4 otherwise it will not display. Also check that 'Enable Vision Positioning' is enabled in the Advanced Settings section of the Visual Navigations Settings menu. If the OA screen display icon is white it means there is sufficient light for it to work, and OA is active, otherwise it turns red when OA is disabled or insufficient light.

As well as updating firmware to .0700, the RC also needs to be updated to V1.9.3 otherwise there will be problems with display.

See screen grab from my 6S plus:-

Also there shouldn't be any problems in calibrating the VPS on the P4 with the last release of firmware from January last year, as production of the P4 itself ceased on April 30th 2017.

From the P4 release notes:-


2018.01.24
Overview • Aircraft Firmware: v02.00.0700 • Remote Controller Firmware: v1.9.3.0 • DJI GO 4 App iOS: v4.1.22 • DJI GO 4 App Android: v4.1.22

Aardvark Posted at 3-6 09:34
"I used an iPhone 6S"

I use an iPhone 6S plus with my P4, which displays the 'radar' for the front Obstacle Avoidance sensors.

Thank you once again... finally I am able to upload some screenshots from my iphone 6S. Latest dji go 4 app version, upgraded firmware to 0700 too for the P4, transmitter is already on latest fw
This is what I get even with all the options enabled :/ maybe its a setting elsewhere? I did another calibration for the sensors once again, and I can clearly see what the sensors see while picking up the patterns on the pc screen so definately they work and calibration completes "successfully" and I restart the aircraft but still nada! maybe its another setting else where? I dont know what else to do. I really don't fly with the sensors and dont care too much for them (the forward ones) but I would like to know that the bottom ones are there and working to make a good landing and pick a suitable landing area in case of a failsafe autoland or a return to home failsafe!

georgios87 Posted at 3-6 11:13
Thank you once again... finally I am able to upload some screenshots from my iphone 6S. Latest dji go 4 app version, upgraded firmware to 0700 too for the P4, transmitter is already on latest fw
This is what I get even with all the options enabled :/ maybe its a setting elsewhere? I did another calibration for the sensors once again, and I can clearly see what the sensors see while picking up the patterns on the pc screen so definately they work and calibration completes "successfully" and I restart the aircraft but still nada! maybe its another setting else where? I dont know what else to do. I really don't fly with the sensors and dont care too much for them (the forward ones) but I would like to know that the bottom ones are there and working to make a good landing and pick a suitable landing area in case of a failsafe autoland or a return to home failsafe!

First thing I would try is relinking the RC to the aircraft, just to rule out any problems there. In 'About' the aircraft  firmware version should be transmitted from the aircraft to the RC then to display device.

If that has no affect, then try a firmware refresh & factory reset in Assistant 2. There may be a glitch in the firmware causing the problems you're seeing. The aircraft battery should be fully charged before performing updates, there is a requirement that the battery needs to be at least at 50%, but I suspect it might stop if it drops below that.

Aardvark Posted at 3-6 13:00
First thing I would try is relinking the RC to the aircraft, just to rule out any problems there. In 'About' the aircraft  firmware version should be transmitted from the aircraft to the RC then to display device.

If that has no affect, then try a firmware refresh & factory reset in Assistant 2. There may be a glitch in the firmware causing the problems you're seeing. The aircraft battery should be fully charged before performing updates, there is a requirement that the battery needs to be at least at 50%, but I suspect it might stop if it drops below that.

Great ideas, thanks! I will try and report back. Have you seen this problem before? isn't it weird? if I can't get it to work its not a dealbreaker for me, just weird problem. and also the fact that you dont see the aircraft version raised my attention as well. I will keep you updated!

georgios87 Posted at 3-6 13:04
Great ideas, thanks! I will try and report back. Have you seen this problem before? isn't it weird? if I can't get it to work its not a dealbreaker for me, just weird problem. and also the fact that you dont see the aircraft version raised my attention as well. I will keep you updated!

Ok, update:
Just tried the following (nothing fixed it)
1. update to latest ac fw. Before that I tried factory reset settings.
2. downgrade rc version all the way to 1.5.8 (tried 1.6.0 and 1.8.0 as well). Nothing, the older rc versions made the video impossibly laggy, reupdated the rc fw to 1.9.3, fixed the video lag issues
3. deleted and reinstalled dji go 4 app in my iPhone 6S
4. Downgraded to earlier ac fw that was there when I got the P4 in the firstplace
5. turned all sensors off and on again

It is ok, I will use as is, not a dealbreaker but such a shame... you know? because the sensors worked, I recalibrated again and calibration was succesfull! If they were broken I wouldn't care to look into fixing all this, but the fact that they work great during calibration is causing my ocd self such a big itch
Oh well, thats ok
Thank you all for your help and for taking the time to answer my questions or come up with ideas about fixing this issue

georgios87 Posted at 3-6 14:59
Ok, update:
Just tried the following (nothing fixed it)
1. update to latest ac fw. Before that I tried factory reset settings.

"3. deleted and reinstalled dji go 4 app in my iPhone 6S"

When you deleted the DJI Go 4 App' did you delete it in Settings / General / iPhone Storage / DJI Go 4, this removes all App' folders and files from device; rather than just 'offloading App' (have a look it may be worthwhile).

Aardvark Posted at 3-6 16:16
"3. deleted and reinstalled dji go 4 app in my iPhone 6S"

When you deleted the DJI Go 4 App' did you delete it in Settings / General / iPhone Storage / DJI Go 4, this removes all App' folders and files from device; rather than just 'offloading App' (have a look it may be worthwhile).

No I just did the typical offload... hmm I will give it a shot thank you very much! good day to you sir