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Litchi Waypoint Curiosities

Discussion in 'Pro/Adv Discussion' started by dirtbird, May 16, 2016.

  1. dirtbird

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    I've been researching how to properly accomplish a Litchi Waypoint Mission. I'm feeling better around what I've learned, but I still have some curiosities I would like to understand better before actually doing it:

    1. I'm assuming you may start a mission in two ways: a) just flying around in P-Mode, then drop the remote control in to F-mode, and then start your waypoint mission OR b) simply start the mission from the ground. The motors should spin up on their own and then head to the first waypoint.

    2. If 1. is correct then I'm assuming 1. a. is the safest...right? Personally, I don't feel comfortable with the compass and general operations with the bird until I've gotten to stare at it just safely hovering for about 30 seconds first.

    3. In either scenario with 1. how does the bird get to the first waypoint? If it is starting from the ground does it ascend to waypoint 1's height first and then make its way to waypoint 1 OR does it climb and make its way to the first waypoint at the same time? It seems logical that the first scenario would be safest, but I would like to be sure that in reality this is what happens. Additionally, would same hold true for starting a mission anywhere, that is, once the mission is started, no matter where it is flying, it first aligns itself with the same height as waypoint 1 and then and only then makes its way there?

    4. Where does the scripting reside for the bird to know all the waypoint locations and their attributes? I've seen a number of videos where the bird loses connectivity with the remote control for a period of time. In some cases as much as many minutes (not something I plan to try). Ultimately, (and amazingly) the bird completes the full waypoint mission and returns so I've got assume the scripting to accomplish all this is uploaded to the bird itself when the mission is started...correct? How else could it complete the mission without connectivity to anything else?

    5. I've heard a couple horror stories using Litchi Waypoints that I would like to try and avoid such as the bird just making unexplained movements on its own and potentially crashing. I haven't read many, but enough that leaves me reason for concern. So I would like to be sure I'm ready to bailout in a moment's notice if I see the bird starts reacting in a way I don't expect. I would assume the quickest way to do this is instantly switch the remote control from F-Mode to P-Mode...correct? Wouldn't this just take it immediately out of the waypoint functionality, stop the bird wherever it is, and simply have it hover?

    If so, this might even be a better process when completing a mission. Instead of having the bird RTH you could have it finish at Waypoint 1. I assume it would just hover there. Once there you are likely to be able to easily see it and then move it from F- Model to P-Mode and bring it in manually.
     
  2. Mark The Droner

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    Yes, waypoints is frightening the first time. But like RTH, you learn to trust the system to do what it's designed to do. Having a tracking device on the bird might allay your fears.

    Personally, I am like you, I prefer to launch and hover to be sure the compass is okay. Then I begin the waypoints mission. That's the best way to do it IMO.

    It will angle and approach the first waypoint at the same time, although sometimes it will reach height first depending on the angle.

    The mission is uploaded from the controller to the bird. That's how it knows where to go if it loses RC contact.

    Yes, switching from P to F will regain control if you're within RC. It will do whatever your sticks are telling it to do (centered sticks will hover).

    The mission will complete at the last waypoint and then hover and await your command. Hence, you want to be within view of the last waypoint.

    Be sure you have plenty of satellites before you launch.

    Hope this helps.
     
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  3. dirtbird

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    Huge help! Thanks. So it ascends and angles to the first waypoint regardless of whether it comes from the ground or is already in mid-flight somewhere? Boy, that sounds like a bit of a design flaw to me. From the ground if the bird doesn't have perfect line of sight to the first waypoint I could see where it would just run in to something like a tree. At least I know now. Safest thing to me seems to just fly it manually somewhere close to the first waypoint and then start the mission. Thanks again.
     
  4. ChrisA

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    When I program Litchi waypoint missions I make the first and last waypoint directly above my take off position for that exact reason. I launch my bird and hover for a minute or so, close the Go app and open Litchi, switch to F mode and then load the mission. Then I fly my bird close to the starting altitude and press start. I was nervous the first couple times but It's worked perfectly for me every time.

    Here's a link to a few I've done - Air Long Beach
     
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  5. dirtbird

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    Why start with the DJI GO app at all if you are doing a Litchi Waypoint Mission?
     
  6. ChrisA

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    I do my calibrations with the GO app (the only way I know how) first. It's worked for me every time without fail but maybe it's not the only way.

    When I first started using the app I had some connectivity issues because of my stupidity. The people at Litchi instructed me to do it this way and it's been fine.
     
  7. dirtbird

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    Weird. I wouldn't expect Litchi to recommend using a competitor's product first. It reminds of when Apple recommended Google Maps since their own maps product was so poor. :)

    Anyway, thanks for your experience and I'll probably do just as you are saying. Although it does make me nervous to close out one app to use another mid-flight, I also have a higher comfort level using the manufacturer's app first to do things like compass calibration and initial take-off. Nice vids too!
     
  8. Fly Dawg

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    Just to throw this out, I personally always set my final Waypoint near the Homepoint and set it in Litchi to "Land" at this Waypoint. As it starts it's decent to land, I switch back to "P" mode and land it manually. Sometimes auto landings can be a bit rough.
     
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  9. Not A Speck Of Cereal

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    A couple of additional thoughts:
    • During a new mission, or one where the bird gets close to objects, I keep a forefinger near the MODE button, read to switch from F to P to stop the mission. Yes, it stops right there and hovers, waiting for you to fly it.
    • What it does when it reaches the last waypoint is programmable. It can stop and hover, land, or RTH.
    • I have done both start a mission from the ground, or start after already in the air. As for the trip reaching the first waypoint, it should be obvious to you when starting from the ground is not advisable. Just eyeball it -- if you have obstacles, you obviously don't want to start on the ground. There is no design flaw here: you can easily program the craft to fly into things if you don't take due care, use common sense.
    • I start with the DJI Go app only if there are settings I want to adjust that the Litchi app does not do. Otherwise, I go straight to the Litchi app.
      I do not calibrate every flight (which is not recommended by most of us, but that's the subject of a different thread).
    • I used to do a lot of pre-programming of missions before launch. Now, I find it much easier to program it in flight. I have the C1 programmed to drop a waypoint, the C2 button to drop a POI. Each time you drop one, the mission records not just the location, but the elevation and compass direction of the craft (and I think the gimbal tilt setting, I think but am not sure).
      Pre-programming still sounds useful though, especially when it's a long one with some waypoints not being nearby.
    • Some settings are still in need of improvement. I find that the missions still require some manual tweaking with the stick or gimbal tilt during flight. The "focus on POI" doesn't seem very reliable. You can't change the speed of the mission during the mission, only a single mission setting at the start.
     
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  10. dirtbird

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    Big help. Thanks. Just to touch on a few things you mentioned. Rest assured, I understand the common sense factor when it comes to starting a mission from the ground. I actually don't see myself starting that way at all, BUT if I did then it seems to make more sense for the bird to go straight up to Waypoint 1's altitude and then go there. To angle and ascent (shortest distance between two points) seems a little odd to me. This isn't the logic built in to RTH. Again, just an observation, nothing more.

    The C1 and C2 programming for dropping waypoints and POI's is brilliant! I hadn't thought of that. Thanks for mentioning it.

    You mention "You can't change the speed of the mission during the mission, only a single mission setting at the start." However, you can increase or decrease the throttle during mid-mission to speed up or slow down the bird while it remains on its waypoints path...correct? It is a manual adjustment and nothing that will "stick," but I thought I saw somewhere you could at least accomplish a manual increase in speed while still maintaining the mission's path.
     
  11. Not A Speck Of Cereal

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    I'm not 100% sure. I think most or all of the RC controls work during a mission, but that particular one we'll have to experiment with. I hope so!
     
  12. Mark The Droner

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    I believe if you start a mission from the ground, it first launches straight up for maybe 8 feet or so, hovers for 3 secs or so, and then proceeds from there to the first waypoint. I don't think this is documented. It's just what I remember the one time I launched a mission from the ground. It's not a big deal - it doesn't change how you should plan your mission. Just know it will definitely angle towards the 1st waypoint - and then from there it will angle to the 2nd - and the 3rd - etc.
     
  13. Bigfootbuilt

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    I haven't tried Litchi yet, but I have a question..if you preprogram the waypoint mission online then go out to the location and start the mission, how are the waypoint elevations determined? Example, if I select my 1st waypoint to be at an elevation of 150 ft, what is that elevation in relation to? The exact point I take off from, or the point in where the mission has started (after I put it in a hover and start the mission)?
     
  14. Mark The Droner

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    All the elevations are relative to the launch site, aka the home point.
     
  15. MILLER4PRESIDENT2020

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    so if i program to the waypoints at 1000 feet, and then I go set the homepoint and launch at 5000 feet, it will run the mission at 6000 feet above sea level, 1000 feet above ground level?
     
  16. alokbhargava

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    Yes all references will be set wrt home point.
     
  17. dirtbird

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    Thanks again for all the help and tips here. I went out and tried Litchi for the first time yesterday and did my first waypoint mission as well. Tested all the things mentioned here and they all worked great.

    The only thing I didn't expect, but it was very minor, was how the bird works with the 1st waypoint. I assumed the bird would get to the 1st waypoint and before leaving it adjust the direction of the bird and the gimbal before leaving for the 2nd waypoint. This didn't seem to be what it did. Instead it sort of got to the 1st waypoint, took off toward the 2nd, and then eased in to adjusting direction and lowering the gimbal to where the 1st POI was. Not a huge deal at all and I'm sure there are some settings I could play with to get it to operate differently. Just an observation.

    For me one of the biggest advantages of the Litchi app is to create your missions online and then download them to your tablet. I much prefer fine tuning everything from inside at a desk versus trying to see the screen with the sun outside and juggling things with the bird coupled with trying to fine tune a mission. Fun stuff!
     
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  18. dropke

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    Some one an Idea how i can get rid of 'IOC mode error' when I switch to 'F' in Litchi ? and try to fly WP's ?and the others.Only 'CL' is working correctly
    Error happened now about 2 weeks?(before NO probs)
    DJO Go gives NO ERRORS at all on 'F'
    Using
    App: 2.4.3
    Remote: 1.1.9+
    Firmware:1.4.10

    Litchi v 3.3.1
     
  19. Mark The Droner

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    Isn't IOC set with a switch on your RC? If so, that's the error. You can't fly in IOC and F mode at the same time.*

    *I confess I don't have a P3
     
  20. Norm Walker

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    Tried using waypoints today. It takes about 5mins of hover time to load. Anyone know what is causing this.