Check and double check your home point

[Ben B]

So I wanted to test the RTH function, and the resetting of the home point.
I took off, flew a hundred metres away, and hit the RTH button. All worked fine; it came back to me and started its landing procedure.

I then moved a short way, and chose to update the home point, and repeated the test.
My phone must have experienced GPS drift (not uncommon with mobile phones) so it actually set the home point about 100m away. I didn't notice, so when I hit the RTH again, the drone went merrily flying off over a nearby building. It then lost connection as it went lower, presumably due to the large building being in the way. Luckily, I saw where it had gone, ran over, and it reconnected, so I was able to retreive it no problem. Phew!

So be aware: carefully check your home point on the map when setting or updating it.

 

[Meta4]

My phone must have experienced GPS drift (not uncommon with mobile phones) so it actually set the home point about 100m away. I didn't notice, so when I hit the RTH again, the drone went merrily flying off over a nearby building. It then lost connection as it went lower, presumably due to the large building being in the way.

It would be interesting to see the recorded flight data for that flight to better see what happened.

 

[Ben B]

It would be interesting to see the recorded flight data for that flight to better see what happened.

I'll dig it out. I flew a few times yesterday, so will have to try and find the one.

 

[Ben B]

Should I upload the .txt file or the .dat file?

 

[Meta4]

Should I upload the .txt file or the .dat file?

The .txt file is all that's needed (and it's easier to make sense of).

 

[Ben B]

OK, it's this one.
I think it actually landed on the roof of the building! I'm so lucky.

 

[Meta4]

OK, it's this one.
I think it actually landed on the roof of the building! I'm so lucky.

Lots of confusion in this flight.
Here's what really happened.

You launched and flew for 24 seconds before your drone acquired its first good GPS position fix and was able to record a home point.
This home point was not where you launched, but was where the drone was after 24 seconds of flight.
At 14:25.9 you reset the homepoint to the current location of the drone.
That's the position where the drone was, 644 feet from the first home point.
You did not reset the home point to the spot where you were.

At 14:29.3 you might have initiated RTH (or perhaps you pressed the Autoland screen button by mistake?
The outcome was the same because the drone was within a metre of the new home point.
Page 13 of the mavic Mini manual:
If the aircraft is less than 20 m from the Home Point when the RTH procedure begins, it lands immediately.

It autolanded at 51.33354 -0.26339.

 

[Ben B]

Lots of confusion in this flight.
Here's what really happened.

You launched and flew for 24 seconds before your drone acquired its first good GPS position fix and was able to record a home point.
This home point was not where you launched, but was where the drone was after 24 seconds of flight.
At 14:25.9 you reset the homepoint to the current location of the drone.
That's the position where the drone was, 644 feet from the first home point.
You did not reset the home point to the spot where you were.

At 14:29.3 you might have initiated RTH (or perhaps you pressed the Autoland screen button by mistake?
The outcome was the same because the drone was within a metre of the new home point.
Page 13 of the mavic Mini manual:
If the aircraft is less than 20 m from the Home Point when the RTH procedure begins, it lands immediately.

It autolanded at 51.33354 -0.26339.

OK, that makes sense.

So lessons learned:
- Wait for a good GPS lock before launching.
- Adding new home point sets it where the drone is, not the controller.

I would have thought it would set it to the controller, but good to know - I will manually adjust in future when changing the home point.

 

[Meta4]

- Adding new home point sets it where the drone is, not the controller.
I would have thought it would set it to the controller, but good to know

There are two options when resetting the home point.
You can reset to either:

1. The current location of the drone .. or
2. The current location of the controller (as long as the phone or tablet has GPS enabled)

 

[Ben B]

There are two options when resetting the home point.
You can reset to either:

1. The current location of the drone .. or
2. The current location of the controller (as long as the phone or tablet has GPS enabled)

Great, thanks.
Lesson learned, and big relief that nothing serious happened!

 

[TDZHDTV]

Great, thanks.
Lesson learned, and big relief that nothing serious happened!

Find a large open area and practice, understand RTH scenarios and read this forum threads, lots of ‘fly away’ threads that are actually ‘blown away’ by the wind, you can learn a lot from other people’s mistakes and misfortunes and the analysis from experts\ experienced operator.

 

[Ben B]

Find a large open area and practice, understand RTH scenarios and read this forum threads, lots of ‘fly away’ threads that are actually ‘blown away’ by the wind, you can learn a lot from other people’s mistakes and misfortunes and the analysis from experts\ experienced operator.

Yes, I've been reading a lot of the threads on here, so I am clued in about the wind issues (fly into wind on outbound leg!), and now I know better about RTH functions - I just don't remember seeing the two different modes in the manual, nor when I did it on the app.

Thanks

 

[DaveNagy]

There are two options when resetting the home point.
You can reset to either:

1. The current location of the drone .. or
2. The current location of the controller (as long as the phone or tablet has GPS enabled)

Or, 3, anywhere else on the map, right? I don't have my Mini yet, but I watched a vid of some fella setting the home point to various spots that were well away from either the drone or the controller. (I don't know but I suspect the procedure is to do whatever it is you normally do to set the home point to the drones location, except you scroll the map to a different location before confirming the location.)

Yes, the procedure appears to be:

• Tap the settings "dots"
• On the Safety tab, tap "Update Home Point"
• Map will appear with home point location under drone
• Scroll map and home point marker "away" from drone
• Tap "OK" button

YouTube link

Inquiring minds want to know: How far can the HP be moved? Also: How is elevation handled? (Correctly, one hopes.)

 

[Meta4]

I watched a vid of some fella setting the home point to various spots that were well away from either the drone or the controller.

This is a feature that has not been available in previous DJI models.

Inquiring minds want to know: How is elevation handled? (Correctly, one hopes.)

Elevation of any new home point is irrelevant.
Home points are recorded by the drone as X and Y coordinates only with no altitude information at all.

Resetting the home point is rarely used in normal flying.
This extra method on the MM seems unnecessary and is just going to confuse more new flyers and possibly contribute to losses of a few minis.

 

[Lifeisfun]

I wish there was dynamic home point option like on the spark. Use it all the time when the boat is drifting.