I went to a nearby park to fly my Spark today but this time I thought I'd launch from the parking lot because there wasn't anyone around & I planned on being fast.

I setup my RC & DJI Go 4 app then powered on my Spark and waited for them to connect. Once they did I tapped the Go Fly button and entered the app.

First thing I noticed was it skipped showing me the sensor states and went right to the app which is really uncommon in my experience so far. So I tapped on the GPS status at the top to see the sensor & AC status and everything appeared normal, compass was normal, flight mode switched from ATTI to GPS and looked normal.

I wanted to adjust my RTH altitude because I was surrounded by trees so I went to the AC settings and noticed that the RTH was at 0 (zero). I thought that was really odd so I tried to update it but it told me the update failed, so I tried again and again with the same results.

At this point I'm a little concerned and decided to check the max altitude and it also said 0 (zero), so I tried to set it back to 120 meters and it appeared to take so I returned to the RTH and tried setting it again but again it failed.

Now I'm a little more concerned and decided to try restarting the Go 4 app to see if it was just being stubborn. Once it restarted I tried to update the settings once again but still it wouldn't update.

I had the thought to check the sensor state under advanced settings and when I got there I saw something I had never seen before, wish I had thought to screen shot it but I didn't. The IMU was telling me basically it was unavailable and the indication bars were blank. Next I checked the compass, I don't recall if it said it had interference or was also just unavailable but I feel like it was the later.

At this point I decided that this spot was just not going to work to take off from so I moved into the grassy baseball diamond that I usually take off from.

I reset everything and entered GO FLY in the app. This time it showed me the sensor states as expected.

I went back to the advanced settings to check IMU & Compass and everything looked normal again.

Finally I went back to the RTH settings and the zeros were gone and my old RTH settings of 20 meters was back and the max altitude was set to 120 meters.

After seeing that everything seemed normal again I tried updating the RTH altitude to 60 meters and it took the first try!

I can't say for sure but I wonder if I wasn't really close to experiencing the yaw, compass, GPS errors trifecta that generally precedes a "flyaway".

So glad I tried to update the RTH today! Otherwise most everything looked normal to me and I would have typically taken off.

After three successful flights I went back to the same spot in the parking lot to see if I could reproduce the scenario but nope, everything looked normal. Typical!

Have you ever seen your RTH and/or Max Altitude set to zero?

Happy Landings!

Hi, did you fly your spark with OTG cable? If not, please export the flight data and the black box with this situation for further analysis. You can upload it to dropbox and post the link here. Thanks for your support.

Are you sure Aircraft was turned when checking settings first time around ?

Only time the RTH and Max Altitude shown zero on my app was when the RC is connected but the AC was switched off.

I wonder like computer programs sometimes do not load right the app did not.. i had one time when my spark went crazy on takeoff but landed it safe. i did check all on the app and was good before lifting off but after seen a odd thing as the battery showed bars but no info as times charged or any other.  after shutting down all restarted and all was good and had all of the battery info.

hallmark007 Posted at 2018-3-10 03:30
Are you sure Aircraft was turned when checking settings first time around ?

hallmark007, do you work for Microsoft Tech Support by chance? ;)  Fair question though.

Yah, it was on, I use an OTG cable with my RC so I waited until the AC & RC linked to plug in my cable.

Also, I'm not aware of any way to get into the GoFly portion of the app unless the AC is on and linked. Other than linking it once then turning the AC off I guess, but from start up I don't know how it would be possible. Is there a way?

Thanks for responding!

Ram-UK Posted at 2018-3-10 09:20
Only time the RTH and Max Altitude shown zero on my app was when the RC is connected but the AC was switched off.

Ram-UK, thanks for the reply.

I was linked to the AC with my RC (had a green link light) and the app was showing me sensor status and GPS satellites and everything else looked normal.

I'm trying to export the FC & Black box data for DJI, they said only if I wasn't using an OTG cable, which I am but I figure I'll do it anyway.

DJI Elektra Posted at 2018-3-9 23:46
Hi, did you fly your spark with OTG cable? If not, please export the flight data and the black box with this situation for further analysis. You can upload it to dropbox and post the link here. Thanks for your support.
https://www.youtube.com/watch?v=ngEHdAlAh9A

Elektra, thank you for the reply.

Yes, I am using an OTG cable with DJI Go 4 app version 4.1.15 on Android, so if you don't wish to explore further I understand but thought I'd share the data anyway.

DropBox link: https://www.dropbox.com/sh/s2zx5 ... p5wbiI6k9dJcua?dl=0

I fly with:
Phone: Samsung S7
OS: Android 7
Location: U.S.A
Carrier: AT&T
App Version: DJI Go 4 v4.1.15
Spark: Firmware 01.00.0900
Remote Controller: Firmware Latest I believe, not sure the version
Connection: OTG Cable, this is why I use Go 4 v4.1.15


This is my first occurrence of this scenario so I'll keep a close eye on it to see if it happens again.

Everything about the connection, app, sensors and AC looked just like any other flight until I tried to update the RTH altitude.

I looked for a flight log but I guess because I never lifted off there wasn't one created. Maybe?

Let me know if you need any additional information.

Thanks!

Rodador Posted at 2018-3-10 10:53
hallmark007, do you work for Microsoft Tech Support by chance? ;)  Fair question though.

Yah, it was on, I use an OTG cable with my RC so I waited until the AC & RC linked to plug in my cable.

Ahh ok bit of a silly question, otg explains it.

Good catch, I have a friend that made fun of me for doing a preflight before I fly, but then again I got to fly yesterday and he is still looking for his Spark today!?!?

Rodador Posted at 2018-3-10 12:03
Elektra, thank you for the reply.

Yes, I am using an OTG cable with DJI Go 4 app version 4.1.15 on Android, so if you don't wish to explore further I understand but thought I'd share the data anyway.

Thanks for the detail. We would recommend users fly with wifi connection for your drone's safety. I would forward your data for further check. Please wait patiently.

Rodador Posted at 2018-3-10 10:53
hallmark007, do you work for Microsoft Tech Support by chance? ;)  Fair question though.

Yah, it was on, I use an OTG cable with my RC so I waited until the AC & RC linked to plug in my cable.

Yes, you can enter the fly portion of the app with Spark off and the settings you mention will all be 0.

Hddeuce Posted at 2018-3-12 12:45
Yes, you can enter the fly portion of the app with Spark off and the settings you mention will all be 0.

Hddeuce, I can't see how, here's a screen shot of the app on my phone no RC or Spark connection. Can you list the steps to do so?

I only see the GoFly after my phone is connected to my RC and the RC is connected to the Spark. As I listed above, my usual procedure is turn on the RC - turn on Spark - wait for green connection light on RC - plug in OTG cable to the RC from the phone then I get the Connected message & GoFly button.

Thanks!     

Rodador Posted at 2018-3-12 13:44
Hddeuce, I can't see how, here's a screen shot of the app on my phone no RC or Spark connection. Can you list the steps to do so?

I only see the GoFly after my phone is connected to my RC and the RC is connected to the Spark. As I listed above, my usual procedure is turn on the RC - turn on Spark - wait for green connection light on RC - plug in OTG cable to the RC from the phone then I get the Connected message & GoFly button.

If you press the "enter device" it will take you to the "fly" portion of the app.  It doesn't say "GoFly", but it's the same area.  Once in there, you will see everything as if your AC was powered on, but of course will say AC disconnected and a lot of the settings will be 0.

Hddeuce Posted at 2018-3-13 05:31
If you press the "enter device" it will take you to the "fly" portion of the app.  It doesn't say "GoFly", but it's the same area.  Once in there, you will see everything as if your AC was powered on, but of course will say AC disconnected and a lot of the settings will be 0.

That's interesting, on mine it takes me to the list of available Wifi networks, not into the fly portion of the app.

It's like it's looking for a Spark to connect to.

Maybe it's different on iOS and Android? Are you on iOS?

Rodador Posted at 2018-3-13 05:47
That's interesting, on mine it takes me to the list of available Wifi networks, not into the fly portion of the app.

It's like it's looking for a Spark to connect to.

It's the same way on both Android and iOS.  Here are screenshots from Android.  Once you select "enter device", you then select "enter camera view".  You will then be in the normal flying part.

Hddeuce Posted at 2018-3-13 11:29
It's the same way on both Android and iOS.  Here are screenshots from Android.  Once you select "enter device", you then select "enter camera view".  You will then be in the normal flying part.

I wonder if it's because I'm using an older version of the app then? I'm on 4.1.15 for OTG cable support.

Rodador Posted at 2018-3-13 12:31
I wonder if it's because I'm using an older version of the app then? I'm on 4.1.15 for OTG cable support.

When I used 4.1.15 with Android, I had these same basic menu's.  So you are saying that if you have nothing connected, enter the app, and select enter device, you don't get the screen I posted above?

Hddeuce Posted at 2018-3-14 06:02
When I used 4.1.15 with Android, I had these same basic menu's.  So you are saying that if you have nothing connected, enter the app, and select enter device, you don't get the screen I posted above?

Yah, I'll try to upload a short video.

Hddeuce Posted at 2018-3-14 06:02
When I used 4.1.15 with Android, I had these same basic menu's.  So you are saying that if you have nothing connected, enter the app, and select enter device, you don't get the screen I posted above?

Looks like the upload didn't work, here's a link to it on YouTube.

https://youtu.be/Iio8V3T-Fv0

I know that this discussion includes OTG but do you suppose that the exact place in the parking lot had something under the pavement (metal or a power line in plastic conduit for lights) that might explain the problem?  Since it could not be reproduced in the parking lot maybe it was not close enough to the exact same spot.

I try to read all of these posts about loss of GPS and compass and other than the OTG cable lots of it seems somewhat random.

I have not flown in a while because of the local cold weather but that should not be a problem much longer.  I have not yet flown with the latest GO app but it would be nice for DJI to have a "light bulb moment" and find a definitive cause of the fly aways.  Because of these posts it makes me a very conservative pilot and maybe not get some of the photos and videos I would like.

Mark S Posted at 2018-3-14 08:55
I know that this discussion includes OTG but do you suppose that the exact place in the parking lot had something under the pavement (metal or a power line in plastic conduit for lights) that might explain the problem?  Since it could not be reproduced in the parking lot maybe it was not close enough to the exact same spot.

I try to read all of these posts about loss of GPS and compass and other than the OTG cable lots of it seems somewhat random.

Mark, yah, I considered this when I tried to reproduce it. It was an asphalt top and it had some tar lines to seal cracks and I had put it in the middle of a "circle" of this tar so it was actually pretty easy to identify the exact spot again.

I plan to go back again and try another day, it would actually be great if I could get it to work, or fail depending on how you look at it I guess. If I can get the exact same results again I will actually do a short flight, up a few meters and then right back down, just to get some flight data too.

Thanks for the comment!

Happy Landings!

Rodador Posted at 2018-3-14 09:44
Mark, yah, I considered this when I tried to reproduce it. It was an asphalt top and it had some tar lines to seal cracks and I had put it in the middle of a "circle" of this tar so it was actually pretty easy to identify the exact spot again.

I plan to go back again and try another day, it would actually be great if I could get it to work, or fail depending on how you look at it I guess. If I can get the exact same results again I will actually do a short flight, up a few meters and then right back down, just to get some flight data too.

Hi, it seems that your spark works normally, the '0' in the setting may be caused by OTG cable, please try to use without OTG cable. Thanks for your support.  

DJI Elektra Posted at 2018-4-3 03:12
Hi, after data analysis, we did not find any error in your flight. The '0' in the setting may be caused by OTG cable. Thanks for your support.

Thank you for the follow up.

I have since stopped using the OTG cable.

Even without the use of OTG cable and using the newest app I still have experienced the RTH & Max Elevation set to zero.

Out of 6 or so flights I've seen it three (3) more times. Even more now that I'm not using OTG. I have flown after seeing this and should have some flight data to go with it.

I am going to fly some more to gather more data then I will send you my flight data again.

Thanks


Happy Landings!

Rodador Posted at 2018-4-3 08:01
Thank you for the follow up.

I have since stopped using the OTG cable.

In this case, please shoot a video with the situation or more info for further check. Please keep us updated, if the problem remains. Thanks for your support.