Litchi Waypoints: Altitude vs Above Ground

[airnocker]

Personally, I like having the option and not defaulting to AGL.

So its a recent feature addition, good to know. I most definitely like having the option, however, I would find value in being able to set the default AGL or no AGL.

Fly Dawg, would you answer this Litchi newbie question? Yesterday I intended to trial my first fairly basic "park" waypoint mission with my P3P. Initialized the RC and drone in the normal way (RC in P-mode) prior to starting a flight app, started Litchi, loaded park mission, flipped RC to F-mode and got "mission failed to load". Should I be in F-mode on the RC first prior to loading missions? I decided not to take chances due to ignorance and just flew with DJI Go instead until I got this resolved.

Thanks

 

[Fly Dawg]

Should I be in F-mode on the RC first prior to loading missions?

Just my preference, but I always wait until the Home Point is updated. Then switch to F and load the mission prior to takeoff. You can load after and that should be fine as well. I have just always acquired and pre-flight manually prior to switching.

 

[bsartist]

So its a recent feature addition, good to know. I most definitely like having the option, however, I would find value in being able to set the default AGL or no AGL.

Fly Dawg, would you answer this Litchi newbie question? Yesterday I intended to trial my first fairly basic "park" waypoint mission with my P3P. Initialized the RC and drone in the normal way (RC in P-mode) prior to starting a flight app, started Litchi, loaded park mission, flipped RC to F-mode and got "mission failed to load". Should I be in F-mode on the RC first prior to loading missions? I decided not to take chances due to ignorance and just flew with DJI Go instead until I got this resolved.

Thanks

Can’t remember 100% if order matters there. My aging memory tells me that you only need to be in F more before hitting the run button. It may also be that there is something else wrong with your mission. There are some rules you can’t break. Like starting waypoint too far, too long a distance between waypoint and such. However I think litchi is pretty good about throwing pretty informative error messages in these cases.

 

[bsartist]

Thanks Bill, your 2 cents are a valuable insight.

This has probably been discussed many times in the past, but shouldn't "Above Ground" be checked as the default?

Sticky one.

As mentioned, this feature was added well after initial release. So I think it would be kind of “pulling a fast” one on experienced litchi users to switch the default on them. I think that’s probably a good reason not to mess with the default. (Maybe not a good reason to not give us a preference setting though.)

Another justification for not making AGL the default: as we have discussed, it’s kind of a nuanced option. You need to really understand how it works and not shoot yourself in the foot. So pushing that on mission programmers as the default may not be a good idea. And may incur some liability.

 

[airnocker]

sar104, the screenshots I posted were from my initial mission creations, so at first, I did not know or understand the importance or significance of have the "Above Ground" box checked. I'm now getting the impression that because my first mission that did not have the box checked the resulting KML screenshot showed a gradual ascent from "home" launch altitude of Waypoint 1 to Waypoint 2 and that this was solely due to my not checking the "Above Ground" box of Waypoint 1.

Once I modified all my original waypoints to have the "Above Ground box checked, the exported KML file seemed to show an immediate vertical ascent from Waypoint 1 to mission "altitude" prior to proceeding to Waypoint 2.

Thanks for you help in making this mission waypoint properties behavior clear to me.

Well, to confess ignorance and update this post of mine, my initial impressions for how waypoints/settings worked were wrong. The sloping ascent from waypoint 1 to 2 was due to waypoint 1's altitude set to 3ft while waypoint 2 was much higher. For some reason, after I initially changed waypoint 1's altitude to 101ft, I did not save a new KML file of this mission.

I've since learned (and embedded into mental consciousness) the 3D distance between adjacent waypoints must be a minimum of 0.5m and less than 2000m. Fortunately, all of mine were, even when my bright idea of stacking Waypoint 1 at 3ft altitude under Waypoint 15 at 101ft altitude was trialed as a software "test", but as sar104 implied, there is no advantage to doing so.

So far, all of my saved missions meet the waypoint distance criteria, I just haven't gotten one of them to upload to my P3P yet. I've made some new very simple, test waypoint missions consisting of only 4 waypoints within 20 yards of each other I'll try next. If they won't upload I guess I'll try to delete and reload Litchi app on my iPad Air 2.