Hello,

How do I set the Return to Home RTH battery level for Litchi? In DJI go there is an option to set the Low and Critical Low levels. The first is just a warning and the second will RTH (or what ever action is set).

Thanks.

Not sure on Litchi, I think it's whatever the Go app set it to, could be wrong. But your post is wrong on one point. The first is just a warning like you said. But the "critical" level is were the craft will auto land right where it's at. Set that too low and it could land far from home. The point where it will auto RTH is the point of the floating "H" on the battery level line.

Those security settings are stored in the Phantom. AFAIK you can only configure them through DJI GO. You can choose what it should do at critical level (land/RTH).
I left the defaults which are sensible. When I fly Litchi i get Warning at 30%, and at 20% "Aircraft is requesting Return to home", which is then engaged after 5 seconds. Both on FPV or Mission flight mode. You can cancel or interrupt it and retake control, since the June update.

Sebb Posted at 2016-7-12 16:27
Those security settings are stored in the Phantom. AFAIK you can only configure them through DJI GO. ...

It was my understanding the the "critical" level (default on my system was 10%) was land only! And the auto RTH with that 5 second warning was set by the software (Go app) which is a moving target depending on how far your out at the time. So the option to choose between hover, land or RTH is NOT the critical level, but the "H" set by app on the battery power line.

Thanks. I'll check those setting in DJI GO and then see if they update in Litchi. It makes sense that they're stored in the craft.

wmcvey Posted at 2016-7-12 12:11
Not sure on Litchi, I think it's whatever the Go app set it to, could be wrong. But your post is wrong on one point. The first is just a warning like you said. But the "critical" level is were the craft will auto land right where it's at. Set that too low and it could land far from home. The point where it will auto RTH is the point of the floating "H" on the battery level line.

This is not correct.  You are confused and  confusing others.  Regards.

wmcvey Posted at 2016-7-12 13:23
It was my understanding the the "critical" level (default on my system was 10%) was land only! And the auto RTH with that 5 second warning was set by the software (Go app) which is a moving target depending on how far your out at the time. So the option to choose between hover, land or RTH is NOT the critical level, but the "H" set by app on the battery power line.

Correct.

Once you hit true critical - you can only deflect the AC on its landing ... you cannot stop it.

As to OP's question ... you set all alarms / criticals with GO and they are set IN the AC ... so when you use Litchi - it will still use those.

Nigel

BobBob Posted at 2017-8-30 08:43
This is not correct.  You are confused and  confusing others.  Regards.

Page 13 of your manual ...

When GO calculates that Low battery is only sufficient to get you home - it will warn you ... you then have 10 secs to decide ... if no action - Auto RTH will initiate. You can cancel it if you wish ...

Once battery level is reached that GO calculates it can only descend to land safely - it will initiate auto land. You can only deflect the position it lands. You cannot cancel it.

Sorry ... but Page 13 says he's near right and you are wrong.

Nigel

quadpilot Posted at 2017-8-30 14:34
hi Nigel
i have set the go app to critical level 10% and 1st warning to 30%
when flying using Litchi it does say warning battery 30% but it never does a RTH

Hi QuadPilot.

You are right.

Using Litchi, SMART RTH WARNING is under speech settings.  It is only a voice warning, that  does not affect your flight characteristics at all.  You can say it is a decorative function.  It will never do a RTH as you correctly say.  You can set it wether using Litchi or using GO (Aircraft Battery Settings/Low Battery Warning).  What you set using GO will be reflected on Litchi.

On Litchi, you CAN NOT set the CRITICALLY LOW BATTERY WARNING, you must use GO.  This setting is very important and really critical, mainly when your are flying Litchi Missions (fully autonomous).  This setting is not a warning but an actual limit for the AC to make autonomous decisions.  When this signal is triggered, the AC will land wherever it is.  So you must be careful of being in the right place at that moment.

One confusion here very common (maybe not yours) is what happen when during a mission, the AC CALCULATES (it is the aircraft who makes the calculation, not GO, GO could be disconnected) at any portion of the flight that it will not be able to complete the rest of the mission.  On this situation, the AC will enter into the RTH procedure if and only if THE SMART RTH setting WAS ENABLED before departure. If you do not enable it, the AC will continue its mission till the point where it gets the CRITICAL low battery level and will land at that point.

If Smart Return To Home (RTH) is enabled before any mission, you can be assured (to the extent of Murphy's Law) that your drone will not be lost.

As important as enabling RTH function, is setting the RTH altitude.  Please pay careful attention to this setting, because when the drone kick in the RTH procedure, it will go first to this altitude and then will get a unique heading, pointing to HOME position and flying to there horizontally.   If you set it to 500 m and do not need it, you will spend battery unnecessarily and will activate RTH more promptly.

Nevertheless, there exist situations on which you could want to have Smart RTH disabled, as when flying over the water around a boat or even when you desire to land in the middle of a mission, before returning to the initial waypoint.  To get this you should have to have many fake waypoints over the landing waypoint, that force the drone to go up and down over the desired landing point, till its battery gets depleted (i.e. it gets the CRITICALLY LOW BATTERY WARNING LEVEL).

My personal recommendation is that you assume that your drone will be out of control and that it will take autonomous decisions, so carefully do your planning and setting of the flying parameters.

To be sure of all that I have exposed here, you must transcend page 13 of the manual, by far.

I hope this exposition will can help others to be more confident to the RTH function.

Regards.


P.S.:  One misterious issue is why DJI do not include all of these details on their manuals.  My guess is one out of two:  It is an accelerated world or they want you to ask them in order to make use statistics  

quadpilot Posted at 2017-8-31 05:53
Brilliant answer Bob Bob
thanks for all you time spent typing all this out, and explaining it for me
i have printed this off for future reference

Your very welcome.

Thank you.