Ground Station + Zenmuse H3-2D Control, is it possible

[iflynavy]

In reading the manual it appears that the Ground Station can control the F series ports on the wookong for servo control. Is one of those tied to the Gimbal at all? I ask because it would be nice to be able to control the camera without having to reach over and use the physical transmitter. Not to mention when doing the aerial photography it would be helpful in order be able to create a series of waypoints and also be able to adjust the gimbal along the way for different reasons.

For example, creating a series of waypoints in a line where you can have the gimbal point straight down in the middle waypoint then back up.

 

[srbell]

Yes...well sort of. It's a double edged sword unfortunately. You can simply use the F1 output (WKm gimbal set to off) and plug it into the shutter port on the Zen controller. Then go into your general servo control set the initial position at 900, first action -900 and 1 second delay. This will work fine, but the problem is you can't use your radio now to manually activate the shutter. So what I did was run the signal wire from my radio rx and the other from my F1 port to a manual switch. When I fly photogrammetry from GCS I switch it one way and for my camera man (women) to control the shutter I switch the other way. It all sounds great doesn't it? Here's the catch. GCS was developed for the Ace One autopilot using a servo to activate the shutter. There's no way to get around it, shutter release will swing the pulse width from one extreme and back. With the Zen, that means two shutter releases for each action. DJI tried to fix some of the photogrammetry issues buy changing the way the iOSD records these actions. Instead of 50hz, it now records the long lat alt for each action. Unfortunately, these way more photos than data fields so there's no way to sync photos to position. Could be solved by adding a time stamp to the data, but DJI refuses. On top of that, how hard would it be for DJI to update GCS to deal with the Zen's shutter issue. Doesn't seem to be any interest from them whatsoever. I worked on it for a while with one of their engineers, but now they don't respond to any of my emails lol. I simply use a separate data logger. Seems silly when cheap autopilots like the APM 2.6 and PX4 not only record all the correct data, but merge it with the photos all within their ground control software....all for less than $200. Did I mention unlimited waypoints? Oh man, I'm starting to rant. Wire it up like I said and buy a data logger. Make sure it can log once per second, some don't. Also, you'll want a hand held GPS with seconds. You'll shoot you first image recording it's time...

 

[iflynavy]

@srbell

Thanks for the detailed response. I printed it to keep for the future Since it's the Zenmuse H3-2D its only for a GoPro camera which I don't believe has shutter control, or does it? I didn't think it did but if you know that it does let me know I think my issue is going to have to be flight speed vs Auto Capture setting. For instance the GoPro can capture images every 5 seconds.... I could create waypoints where the aircraft holds at a waypoint for lets say 10 seconds to make sure it gets at least one image, and then move on to the other waypoints following suit

I agree with you regarding DJI and Customer Service, see my rant here: http://www.multirotorforums.com/showthread.php?13036-Long-Delivery-of-Wookong-then-just-as-long-for-new-Serial-for-waypoints

I am shocked at which features they are simply missing or screwed up. It's strange to me because in reality they seem to be the easiest features of the whole Ground Station, like you mentioned the syncing of photos between position. One that kills me since I do more video is the ability to set the orientation of the aircraft. They have it implemented so you can go to a waypoint, hold and pick your facing direction, but why not say I want to go to this point as a left bank, or backwards or.... I think of flying a box where I may want to keep making left banks the whole way around so my camera is always facing the inside of the box.

Same with POI, you can do it with the controller, but you can put a push pin on the ground station and set it as a POI with range and distance to shoot from?

Now with APM, there is the datalink issue though isn't there? I thought they didn't have a decent or comparable datalink system with the range. I thought they used WIFI which had a very limiting range. That's what I would need, I'm covering some good distances.

I fly an xAircraft Modified v650, the superx that just came out looks awesome and everyone is saying it's better then a wookong. They are developing a ground station for that, be interesting to see what comes of that, because I have a feeling it's going to kick DJI off the top.

 

[srbell]

H3-2D, I didn't even think. As for APM 2.6 data links, the RDF-900 get 40 kilometre range! The modem bundle it about $200 and is compatible with any open source autopilot. Right now I'm using them with the APM, but I'm pretty stoked to try the PX-4. Right now we're working on a long range quad using the new T-Motor U8 motors with 26" props solely for mapping projects.

 

[iflynavy]

If you don't mind me asking, what is your setup?

My first 2 quads are both xAircraft 650 Pro's. One is stock, the other has upgraded Tiger Motors. Get between 14 minutes and 20 minutes of flight time depending on the wind here in Chicago. I thought about trying APM initially but the word on the street was that it was difficult to configure on random quads, vice the one it was built for.

I'm looking to do more long range, longer flights to film our jobsites (Construction Company). Haven't been able to find good posts about builds with longer stable flight times.

 

[srbell]

I've got a few for work. The idea was I cold use the S800 for film/photography and mapping but that isn't panning out with the short flight times. I ended up building a fixed wing (X8) with a custom roll gimbal, RDF900 modem, APM 2.5 and 10ah 4s batteries. It's the only way to get a good sized grid to map. I'd really like to setup a long range multi though, stripped down to the essentials just for photogrammetry. As for the S800 it's got the Zen gimbal/NEX7, second sight cam, 2 VTX's, LK900 modem, retracts, external data logger and two 6s 8ah batteries weighing in at 7.8kg. I'm going to be using the PX-4 autopilot for the new quad and maybe the new T-Motor U8 series motors with large props to push my flight times.View attachment 13330

 

[iflynavy]

ON the new quad what are you going to use for a frame. I was looking at 3DR today and they have some preset packages with the PX-4, APM and the QUAD for not to bad of a price. I jsut couldn't find what they expected for flight times and carry weight.

 

[srbell]

I'll either use something like a Carbon Core 950 quad of build my own. CC is thinking about making a large quad as well. The 3DR package would be a good way to get in the air fast, but the frame is nothing special for endurance. Also note the 3DR radio tele. is the short range version. They work identical, but the RDF900 just has a lot more range.

 

[iflynavy]

@SRbell

I knew the telemetry wouldn't be as good, but that's something like you mentioned, that can be inserted (RDF900)

The overall question then regardless of frame is the motors, esc's and battery to get the endurance as well. I haven't been able to decide if it's better to go with larger frame\blades with lighter motors so you can use a 3S\4S battery or what to do. Oddly enough I have two x650's. One is stock and runs off a 4S battery, the other has more powerful motors has a 6S battery. They both fly about the same, you can tell one has more power but for the application it truly doesn't matter weight\power wise. However the larger one that requires 6s may get a minute or 2 more of flight, especially more in the heavier winds here in Chicago.

DO you think with the CC950 there is a 30minute or greater build in it? Like you mentioned once you have the RDF900 in place and have the range capability now you need the battery to make use of some of that range. That's what I'm running into now, I can go about (Safely, haven't pushed it yet) 5 or 6 minutes out before I need to come back. I'd like to push that out to a mile if I could.

Other then above, what is your thoughts on batteries? For instance you can get some quality high mAh in 3S that are lighter weight then the equiv. in 4S\6S. Is a 3S quad good enough for the distances\wind and what not?

 

[srbell]

I think the CC 950 could exceed 30 min with the U8 motors but at a fair cost. The motors are $300 each and the props are about the same (27"). Not to mention running 12s batteries. I guess you can use 6s to 12s packs, but at 100-170kv, you'd need the voltage to turn a proper rpm. I'll be running some calculations as soon as the U8 motors specs are out.

 

[iflynavy]

Slightly off topic....

Have you had the data link disconnect? Was about 250m out when it appeared to go in and out, either that or GPS I couldn't tell kinda panicked. I was screen recording but at first pass that was having issues and will need to try it on a different computer.

When it happened it just held at that way point I expected after a minute for it to come home which it didn't. When it appeared to be connected again I triggered it myself and it returned.

The logs say mission finished after second way point even though there were 8 total.

Any thoughts?

 

[srbell]

Not sure about in flight, I'm usually not paying attention to the link status. It's always finished it flight plan so I assumed the link was solid. What I have noticed is when uploading the flight plan, it will drop the link and then re establish. A lot of times I have to attempt many time to finally get it uploaded. Just keeps saying "failed, timed out". A little frustrating, but eventually the red go button lights up. I'll be out mapping tomorrow if the weather is good, I'll watch the link status to check. Not like there's a lot to do flying grids lol!

 

[pls4air]

is anyone familiar with the GS photometry servo setting to trigger the camera? we are using sony nex 7. i can take a picture by clicking trigger and reference photo but it will not take photos automatically in flight. i can click reference photo while we are in flight to take pics but really need it to take pics at the planned times.

we to have stopped getting tech support from DJI. I would be greatly appreciated in any help in getting the camera to trigger while on a flight path and how everyone is geo tagging the photos. we completed our first 3D model of a landfill but had to trigger camera manually.

 

[leofuica]

pls4air:
Please send me a work file .awm with the photogrammetric real mission wish you have a reference pics but don´t the others pics in flight and try to develop the mistery...¿ok?
Send me to: info@fuicafoto.cl

 

[srbell]

Well, if you can take a reference photo it should work... Unless you've set the servo to an extremely long delay. Pretty much any setting form 500, -500 to 900, -900 works with 1sec delay. What are you seeing in the editor and when you upload? When uploading you should see basically every second waypoint with an action set to meters. I'd screen shot it, but I'd have to power up the S800 (man, I hate having to do that). Also, in the editor you should see every odd waypoint with an action in meters in the repeat field. I attached a screen shot for a mapping job I'm doing tomorrow. I circled the waypoint and its repeating action in meters. In this case is 20m, but that depends on you overlap and altitude. At least you can check these settings with yours.

is anyone familiar with the GS photometry servo setting to trigger the camera? we are using sony nex 7. i can take a picture by clicking trigger and reference photo but it will not take photos automatically in flight. i can click reference photo while we are in flight to take pics but really need it to take pics at the planned times.

we to have stopped getting tech support from DJI. I would be greatly appreciated in any help in getting the camera to trigger while on a flight path and how everyone is geo tagging the photos. we completed our first 3D model of a landfill but had to trigger camera manually.

 

[maxwelltub]

I think the CC 950 could exceed 30 min with the U8 motors but at a fair cost. The motors are $300 each and the props are about the same (27"). Not to mention running 12s batteries. I guess you can use 6s to 12s packs, but at 100-170kv, you'd need the voltage to turn a proper rpm. I'll be running some calculations as soon as the U8 motors specs are out.

I dont think you could come close to fitting 27" props on a 950? I guess you mean a quad or x8 rather then a hexa?

 

[srbell]

It's a quad but I cheaped out a bit. I used the 950 frame with Foxtech 6135-330 motors and 18" props instead of the U8's and 26" props. Save quite a bit of money over the U8 setup. I'd love to see what's possible with the U8 setup, but I'm getting a solid 40min with a full payload (Sony NEX5n). Still using DJI WKm with a LK900 modem, but I'll try swapping it for a new Pixhawk and a RDF900 modem. I've got modems, but it seems the Pixhawks won't be shipping for another week or two.

I dont think you could come close to fitting 27" props on a 950? I guess you mean a quad or x8 rather then a hexa?