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Blank White Image and FPV quality

Posted: Sun May 05, 2019 2:20 pm
by JasonBSteele
Hi,

I flew my first missions today for a 3D model project but unfortunately encountered two problems.

1. After a battery swap the FPV was showing a totally white image. I ignored this hoping that it was just a problem with the real time FPV, but the images captured were also totally white. :( This happened for the remaining two plans. When I got home and discovered this I connected the app to my Mavic Air again and this time found the FPV to be fine (apart from issue 3 below).

2. After the plans completed I tried to view the captured images by clicking on the camera icons against the flown way points. I received an error saying ""No media found". I was sill connected to the drone at that time. I tried later when unconnected and got "Cannot find image directory on sd card".

3. Before the FPV went white I found the view to be very choppy - lots of artefacts and a left to right sliding affect. I experimented with this when I got home and found that if I switch to video mode it suddenly gets much better, and when I switch back to photo it remains good.

I am using a Mavic Air with very recently updated firmware and DH Basic v1.10, my Android device is a Nexus 7 2013 which has no SD card of it's own.

Re: Blank White Image and FPV quality

Posted: Thu May 09, 2019 10:58 am
by Martin
JasonBSteele wrote:
Sun May 05, 2019 2:20 pm
Hi,

I flew my first missions today for a 3D model project but unfortunately encountered two problems.

1. After a battery swap the FPV was showing a totally white image. I ignored this hoping that it was just a problem with the real time FPV, but the images captured were also totally white. :( This happened for the remaining two plans. When I got home and discovered this I connected the app to my Mavic Air again and this time found the FPV to be fine (apart from issue 3 below).

2. After the plans completed I tried to view the captured images by clicking on the camera icons against the flown way points. I received an error saying ""No media found". I was sill connected to the drone at that time. I tried later when unconnected and got "Cannot find image directory on sd card".

3. Before the FPV went white I found the view to be very choppy - lots of artefacts and a left to right sliding affect. I experimented with this when I got home and found that if I switch to video mode it suddenly gets much better, and when I switch back to photo it remains good.

I am using a Mavic Air with very recently updated firmware and DH Basic v1.10, my Android device is a Nexus 7 2013 which has no SD card of it's own.
Hi JasonBSteele,

A few things are important to note when it comes to the DJI Mavic Air drone:
  1. There are two ways to store footage on Mavic Air: Internal memory or SD Card. Although you can change the storage location in the FPV camera settings, we mention in our release notes, that the Mavic Air SD Card is not fully supported yet (the media viewer/clicking on image icons does not work yet properly in all cases). I suggest sticking to using internal storage for now.
  2. Mavic Air communicates through WiFi with the remote controller. Wifi is more susceptible to signal interference, which can explain bad FPV live video feed.
  3. Generally, it can sometimes happen that DJI drones (or their onboard camera) are in a bad state (visible artifacts). This is not something originating in using Drone Harmony but happens with different DJI drone models and different ground station applications. Usually, a drone & RC restart resolves such issues, or as you did - switch between photo and video recording to "reinitialize" the camera.
In conclusion, support for SD card @ Mavic air and Mavic 2 is missing. Until we add that support in a future update, we recommend using internal memory. The feature is tracked in our backlog here:
https://ideas.droneharmony.com/ideas/DHPLANNER-I-225

Re: Blank White Image and FPV quality

Posted: Sat May 11, 2019 5:01 pm
by JasonBSteele
Hi Martin,

1. Ok, I wasn't aware of that limitation with SD Cards. Hopefully that can be resolved soon.

2. I really don't think this has anything to do with interference. I was in very close proximity, I have tried repeatedly on multiple occasions and other functions were working fine. I still have not managed to get this feature to work at all.

3. Well, ok, but this does seems to happen every time and is something I have only experienced with DH.

Re: Blank White Image and FPV quality

Posted: Thu May 16, 2019 5:40 pm
by Martin
JasonBSteele wrote:
Sat May 11, 2019 5:01 pm
Hi Martin,

1. Ok, I wasn't aware of that limitation with SD Cards. Hopefully that can be resolved soon.

2. I really don't think this has anything to do with interference. I was in very close proximity, I have tried repeatedly on multiple occasions and other functions were working fine. I still have not managed to get this feature to work at all.

3. Well, ok, but this does seems to happen every time and is something I have only experienced with DH.
Hi Jason,

My 3 points are not linked to your 3 points, sorry for the confusion.

The SD Card limitation makes the media viewer not work (as it currently looks for the media on internal storage and not on the sd card).

What part of the issues you described happen every time for you and only with DH?

Note that DJI controls the communication / video transmission of the live feed. The camera widget is also provided by DJI, so it is usually not possible for us to improve or fix issues evolving around the video feed quality. But if there is something that only occurs with our application, we might be able to pinpoint better the problem.

Re: Blank White Image and FPV quality

Posted: Sun Jun 09, 2019 6:42 pm
by JasonBSteele
Hello again.

Finally managed to give this another go today.

The issue with the white pictures seems to be something to do with the exposure being set incorrectly after changing the drone battery (and therefore disconnecting and reconnecting again).

After changing the battery and reconnecting the picture was white. I noticed that AE had a lock symbol so unlocked it and the exposure was correctly set. I clearly need to get a better understanding of what the AE lock is all about but I think there is an issue here with it being set to a bad default value after changing the battery (or reconnecting?). This isn't an issue when I first connect.

I didn't get the poor video refresh rate (choppy) this time, however I did get an odd disconnect. This occurred just after selecting a mission. The mission uploaded successfully and then as then just after the drone launched I got a disconnect from the drone. This was odd as I was only 5m away with the aerials facing the drone. The drone flew it's mission even though it was disconnected and to get it connected again I had to reboot the drone.

Re: Blank White Image and FPV quality

Posted: Tue Jun 11, 2019 7:57 pm
by Martin
JasonBSteele wrote:
Sun Jun 09, 2019 6:42 pm
Hello again.

Finally managed to give this another go today.

The issue with the white pictures seems to be something to do with the exposure being set incorrectly after changing the drone battery (and therefore disconnecting and reconnecting again).

After changing the battery and reconnecting the picture was white. I noticed that AE had a lock symbol so unlocked it and the exposure was correctly set. I clearly need to get a better understanding of what the AE lock is all about but I think there is an issue here with it being set to a bad default value after changing the battery (or reconnecting?). This isn't an issue when I first connect.

I didn't get the poor video refresh rate (choppy) this time, however I did get an odd disconnect. This occurred just after selecting a mission. The mission uploaded successfully and then as then just after the drone launched I got a disconnect from the drone. This was odd as I was only 5m away with the aerials facing the drone. The drone flew it's mission even though it was disconnected and to get it connected again I had to reboot the drone.
Hi Jason,
Thanks for reporting this. Maybe we can actually unlock the AE automatically after the drone reconnects (regardless of battery swap or not) to prevent the white pictures.

Unfortunately, we do not control in any way when and how the drone connects/disconnects. It's all Android USB connection and DJI communication, over which we have zero control. During an autonomous mission and a RC disconnect the DJI drone can either continue the mission or hover in place ( i think we offer this option during launch, by default the drone will continue along the mission).

Best regards,
Martin