RTH Home Point may reset if GO App crashes and is restarted

[Grey Wolf]

Is it possible to set a dynamic homepoint with the Mavic?
Can you film from a car for instance on a raceway?

 

[JLane]

Is it possible to set a dynamic homepoint with the Mavic?
Can you film from a car for instance on a raceway?

No, you can't set a dynamic Home Point, but I don't see why that in itself would stop you from filming from a car.

 

[Hellsbellsidaho]

Have an iPad Mini 4 so not worried about the app crashing.

 

[Grey Wolf]

No, you can't set a dynamic Home Point, but I don't see why that in itself would stop you from filming from a car.

It's a safety thing. Should I lose connectivity, I need to have a backup plan. Conceivably, in a car on a track, I can set home point to grassy area in middle of the course so if I lose connection, it will land there.
Of course, I can always set rth to hover as well.

 

[Logger]

Is it possible to set a dynamic homepoint with the Mavic?
Can you film from a car for instance on a raceway?

Yes, Litchi allows for a true dynamic home point that follows you mobile device dynamically or you can even drag and drop it anywhere manually on the map.

But for what you want you can achieve with DJIGo without this feature. Simply fly your Mavic to your proposed grassy landing area at the start of your flight and while hovering there reset the home point to aircraft. Then get on with your flight in the knowledge it will end up ther should it RTH.

 

[Logger]

Did the latitude & longitude of the home point change in the flight log too?

Sorry can't check that right now. Away from my log viewer software.

 

[msinger]

Sorry can't check that right now. Away from my log viewer software.

We can wait

 

[AlanTheBeast]

It's a safety thing. Should I lose connectivity, I need to have a backup plan. Conceivably, in a car on a track, I can set home point to grassy area in middle of the course so if I lose connection, it will land there.
Of course, I can always set rth to hover as well.

You can set a new Home Point where you are at any time assuming that your phone or tablet has GPS. Not always the case with iPad which has GPS in the cellular version only.

 

[AlanTheBeast]

UPDATE I tried this this evening with the Phantom 4 Pro.

I flew out about 200 m (and turned the drone to face me for easier recovery, "if".)

Cleared the app (in iPhone double click and then "flick away" the app - kills it).

Disconnected the cable from the RC to the iPad.

Restarted the App and connected the cable.

Checked the home position. No change. (I didn't hit RTH, however).

The OP (In Phantom pilots) had the issue following a "crash" of the app, so the above isn't conclusive - but it looks fishy.

That said, following an app crash, best to verify the home position just in case.

 

[msinger]

The OP (In Phantom pilots) had the issue following a "crash" of the app

There is no evidence showing this occurred in that thread. Unless either pilot can produce flight logs that show it happening, we should not simply take their word for it.

 

[AlanTheBeast]

There is no evidence showing this occurred in that thread. Unless either pilot can produce flight logs that show it happening, we should not simply take their word for it.

He showed an image with the Home point clearly in the middle of the river so either it happened as he said or he re-set the home point by accident. No logs, I agree...

 

[Robbyg]

Yeah I agree with msinger, this is whole bunch of hear say. Evidence in the past all points to the home point not changing. If someone wants to make a claim to the contrary they are going to have to produce a few logs that show it happening. A single log could be a one off problem.

Rob

 

[msinger]

He showed an image with the Home point clearly in the middle of the river

Airdata (Healthy Drones) always marks an "H" on the map at the first data point. It doesn't matter whether or not the home point was actually set there.

 

[AlanTheBeast]

Airdata (Healthy Drones) always marks an "H" on the map at the first data point. It doesn't matter whether or not the home point was actually set there.

Got it. Thanks.

 

[JLane]

I was reading about an incident on PhantomPilots and thought I'd share it here.

This is AFAICT UNVERIFIED as NOT TRUE.

View attachment 10477​

It's possible he reset the position via the GO app. But this one makes me nervous.

Update: I tested it - see further down, #29 and the drone maintained its original Home Point.

Since you're investigating this possible bug, I wonder if you happen to have read the following thread on the DJI forums, and this post in particular:

Just Lost My Mavic in the Gulf of Mexico! Help DJI!!

It definitely seems like a new Home Point was set after an app crash and restart. In the second AirData log of the flight, the first data point shows Distance to Home as 0m, whereas the Mavic was still a few hundred meters from the original Home Point.

What do you think?

And worse (although unrelated) was that the app seemed to mistakenly think the Mavic was in a NFZ when it restarted, and it forced the Mavic down into the water.

 

[Oingo Boingo]

Isn't the drone bound to the controller v app
Since the app can crash and drone still connected why would rth change?

Nope not Quite - Let me explain... The Drone is IN NO WAY bound to the app.

The controller is middle man between the drone and the app
The controller sends a signal to the drone - for control - AND THATS IT
The Drone sends Data to the Control that detects if an APP is connected - In return it feeds the data from the drone to the app so its encoded.
You can fly the drone without the APP..... even if the APP crashes

If Youre using an APP like Altizure,, it sends waypoints to the drone from the APP via controller and thats about it

 

[AlanTheBeast]

Since you're investigating this possible bug, I wonder if you happen to have read the following thread on the DJI forums, and this post in particular:

Just Lost My Mavic in the Gulf of Mexico! Help DJI!!

It definitely seems like a new Home Point was set after an app crash and restart. In the second AirData log of the flight, the first data point shows Distance to Home as 0m, whereas the Mavic was still a few hundred meters from the original Home Point.

What do you think?

And worse (although unrelated) was that the app seemed to mistakenly think the Mavic was in a NFZ when it restarted, and it forced the Mavic down into the water.

Others have weighed in on the GofNM flight - I haven't got much time for it now. The issue with the one I looked at was that the first point seen by AirData is labeled "Home Point" even though it is not the Home Point at all. No relationship. So the poster of that thread assumed since AirData called it the "Home Point" that it was so, when it was not. In those data logs decoded by phantomhelp we could see the correctly recorded Home Point as being where he was.

 

[JLane]

Others have weighed in on the GofNM flight - I haven't got much time for it now. The issue with the one I looked at was that the first point seen by AirData is labeled "Home Point" even though it is not the Home Point at all. No relationship. So the poster of that thread assumed since AirData called it the "Home Point" that it was so, when it was not. In those data logs decoded by phantomhelp we could see the correctly recorded Home Point as being where he was.

Yeah, I thought about that, too. But in this case the AirData log doesn't explicitly show the Home Point, but it shows Distance to Home Point as being 0. I am just assuming that value comes straight from the app's log, and isn't simply a calculation made by AirData. I could be wrong, though.

 

[msinger]

But in this case the AirData log doesn't explicitly show the Home Point, but it shows Distance to Home Point as being 0.

Airdata doesn't show a lot of things. Without the actual DJI GO log, all one can go on is assumptions.

 

[RavenStorm]

What concerns me, of course I may be mis-understanding this thread, but I was under the impression that if connection was lost, the Mavic automatically did a RTH, so if the APP crashed to me the best thing to do if the mavic is out of sight is to hit RTH before restarting the APP, at least until you can see it again then restart the APP and regain control if needed.