be carefull where HOME point is set

[tino.v]

This week, I did a short flight from home. No problems whatsoever.

However, after reviewing this flight, I saw that my HOME point was set 79 meters from where I started my MM. 79 meters = 260 feet
When I start my drone and when I hear 'home point recorded', I feel safe and fly away.
Who checks his Home point by looking at the map? I guess not many will do this.

So be warned !

Regards
Tino

 

[sar104]

Your home point was not correctly set until 15 seconds into the flight because you took off without a position lock:

15.2 /HOMEPOINT UPDATED. RTH ALTITUDE ADJUSTED TO 32M

That's why you should wait before taking off until it is confirmed, and why the app tells you to check it on the map.

 

[tino.v]

Yes, I know all this, but this is how I do it most of the times:

I start RC, I start AC and start my motors (if possible)
Then I hover a few meters above the ground (for better GPS reception) till I hear the words 'Home point updated' or such and then I fly off.

Then I think that my home point is good and recorded at where the AC is at that time.

Just wanted to warn people that this is not always the case.

Next time, I'll check the map !

 

[sar104]

Yes, I know all this, but this is how I do it most of the times:

I start RC, I start AC and start my motors (if possible)
Then I hover a few meters above the ground (for better GPS reception) till I hear the words 'Home point updated' or such and then I fly off.

Then I think that my home point is good and recorded at where the AC is at that time.

Just wanted to warn people that this is not always the case.

Next time, I'll check the map !

If you know all that but still don't do it then that's your choice. You also are not checking the navHealth indicator, obviously. It doesn't appear to common practice however - relatively few of the flight issues posted here arise from not checking the home point. Not checking the orientation arrow is a much more common problem.

 

[Airbeaver]

I typically do the exact same thing which is hover and wait for the home point updated audio cue and then I do my control and compass checks.

I'll add this to the routine, it will only add a few seconds thanks for the heads up.

 

[sar104]

I typically do the exact same thing which is hover and wait for the home point updated audio cue and then I do my control and compass checks.

I'll add this to the routine, it will only add a few seconds thanks for the heads up.

You are doing the compass check after takeoff?

 

[tino.v]

What's the navhealth indicator ? Is it the indicator that says: 'it's safe to fly'

And indeed, the orientation indicator is a problem, as it is seldom correct.

 

[Airbeaver]

You are doing the compass check after takeoff?

Yea, for whatever reason 30 plus flights on the mini I cant seem to get an accurate compass reading until after take off / hover and then it orientates itself. I'm not sure what I am doing wrong.

I realize it's not right and I actually almost crashed it yesterday as I had an erratic take off but that was due to taking off on a driveway with rebar in it. Lesson learned on that.

 

[old man mavic]

You are doing the compass check after takeoff?

words fail me,its amazing they still have a drone to return home with

 

[OurAngryBadger]

Is it true that the mavics can "see" and "remember" those bright orange launch pads with the big H on them to improve RTH accuracy, or is that snake oil?

 

[sar104]

Is it true that the mavics can "see" and "remember" those bright orange launch pads with the big H on them to improve RTH accuracy, or is that snake oil?

Any high-contrast target will work but yes - those work well.

 

[sar104]

Yea, for whatever reason 30 plus flights on the mini I cant seem to get an accurate compass reading until after take off / hover and then it orientates itself. I'm not sure what I am doing wrong.

I realize it's not right and I actually almost crashed it yesterday as I had an erratic take off but that was due to taking off on a driveway with rebar in it. Lesson learned on that.

Well that's exactly the problem with waiting until after takeoff to check that the IMU yaw was correctly initialized. If it wasn't, then the answer is definitely not to take off and hope it gets fixed - at least not unless you are flying the Mavic 2, which is the only model that is capable of doing that correction properly. Even then the only time I ever let that happen was during testing that feature, and I had my finger over the ATTI switch while doing it.

 

[THE CYBORG]

And indeed, the orientation indicator is a problem, as it is seldom correct.

I also have problems with the orientation indicator.
I have a Mavic Pro & Pro 2, an iPad & 2 different Android tablets but its hit and miss if the indicator actually points in the same direction as the drone no matter what combination I use.

 

[Airbeaver]

Well that's exactly the problem with waiting until after takeoff to check that the IMU yaw was correctly initialized. If it wasn't, then the answer is definitely not to take off and hope it gets fixed - at least not unless you are flying the Mavic 2, which is the only model that is capable of doing that correction properly. Even then the only time I ever let that happen was during testing that feature, and I had my finger over the ATTI switch while doing it.

I'll do some testing and see what it's going to take to get the minis compass to be accurate before take off. Like I said though for whatever reason it just will not / has not shown as correctly orientated before take off for me yet... It always does it right after take off.

Thanks for the advice on doing it pre take off I'm really new to all of this and I honestly didn't realize it was that important the compass be calibrated just to hover the drone.

 

[Peterson]

You know, I do not remember who gave the advice but it has been said that your RTH accuracy will improve a lot when you take off straight up at least 23 feet and then spin drone (not yourself) a full three sixty slow spin at that altitude before streaking off into Infinity and Beyond. I had small problems myself with RTH accuracy but after trying this with my MP2 it has improved noticeably. I now use the orange landing pad in addition and it will almost land in the exact same spot every time. If I do not do at least the 23 foot lift off with 360 rotation it can be off by as much as a couple of feet.

 

[sar104]

I also have problems with the orientation indicator.
I have a Mavic Pro & Pro 2, an iPad & 2 different Android tablets but its hit and miss if the indicator actually points in the same direction as the drone no matter what combination I use.

Are you referring to the direction relative to the controller, or relative to north? The former depends on the compass in the mobile device, which is often wrong when attached to the RC, while the latter, which is the important one, depends on the compass in the aircraft.

 

[Kilrah]

Is it true that the mavics can "see" and "remember" those bright orange launch pads with the big H on them to improve RTH accuracy, or is that snake oil?

Those that have the "precision landing" feature and it is enabled, yes.

 

[Meta4]

it has been said that your RTH accuracy will improve a lot when you take off straight up at least 23 feet and then spin drone (not yourself) a full three sixty slow spin at that altitude before streaking off
... If I do not do at least the 23 foot lift off with 360 rotation it can be off by as much as a couple of feet.

There is no reason that rotating the drone at 23 feet would do anything to improve RTH accuracy.
Unless you use the precision landing feature which uses optical technology, your RTH accuracy will only be as good as GPS accuracy.
And GPS is not pinpoint accurate at all.
GPS variable inaccuracy will usually be within three metres but can sometimes be even more than that.

 

[Deleted member 114292]

Even with an MP2, I do nothing until the nav status is green.
Check the compass then start the motors.
With an MP2 it is ok to start the AC before the RC and usually I do that so the AC has more warm up time.

 

[charliej]

Yup you need to check. On the pro I am told it has been set and 'check it on the map'. I nearly always do?