Here is what I have going one, and I have found about 10 threads with others having the EXACT same issues, and no resolutions. So what I have is an S900 with Lightbridge 2, A2 Flight controller, GH4-Z15 Camera Gimbal with camera and proper lens. I can see my main stick controls working in the A2 assistant software, as well as the gear channel, and the F-Mode switch. And that is it. From what I have read, the is a VERY good possibility that it is a can-bus issue, and that I may have my CAN wiring out of order...

Following DJI's wiring diagrams and turorials has set me so far back between their own Online youtube video telling you to plug in the Y cable incorrectly between the A2 and Zenmuse controller, and suggesting that I plug in my can hub into my A2 flight controller on CAN2 (Even though these arent even compatible plugs...). I NEED to get this sorted, and following DJI's instructions is clearly not the way to go. Is there anyone that has a fully working set-up like this that would be willing to help me? I will pay at this point, I am 100% out of options. Or is there a shop that builds this stuff, that offers paid tech support? I don't know what to do at this point. And I really need this working by Sunday! (5 Days from now).

Here is a video explaining my connections. I sent an email to DJI and there requests for info are so over the top, it seems like a government agency. I made this video for them, but doubt I will get a usable response as it would be insane to spend the time to provide all the info they want. I provided what would actually be needed to provide an answer. Here is what I have going on now with explained problem:

haha,but I have no camera.

I haven't worked much with the A3 but they do appear somewhat similar. We've run into issues with the CAN1 port requiring use explicitly for a DJI component. In our case it must be connected to the gimbal but we've also made Y-Splitters to extract GPS information into tagging our thermal images. Basically, we found CAN1 is strictly navigation, gimbal controls, etc.

The iOSD shouldn't be necessary at all? I highly recommend starting out bare bones, finding what works and going from there.

I'm still a little bit confused at to what exactly is broken for you, you've probably reiterated it a thousand times to DJI but the OP isn't very clear. Could you list what works, and how its connected, and what does not work and how its connected, any trends? Sounds like just the gimbal information isn't being sent? and obviously not accessible

It sounds like you're connected following this video? If not, try exactly what it says with NONE of your external items connected. You may be able to try it with the LB2 in place of the iOSD but that could be the source of your issue, different passthroughs on the iOSD.

Okay in your video you say the gimbal isn't working, does your LB2 or IMU have a GCU port? I can almost guarantee you the gimbal will need to be on CAN1 some way or another

HyperSpectral Posted at 2018-1-19 06:45
I haven't worked much with the A3 but they do appear somewhat similar. We've run into issues with the CAN1 port requiring use explicitly for a DJI component. In our case it must be connected to the gimbal but we've also made Y-Splitters to extract GPS information into tagging our thermal images. Basically, we found CAN1 is strictly navigation, gimbal controls, etc.

The iOSD shouldn't be necessary at all? I highly recommend starting out bare bones, finding what works and going from there.

I have the A2 connected as in the video, with the exception of the LED, another video told me to plug the Can-Hub into where he plugged the LED into in this video, and then plug the LED into the Can-Hub.

My problem is that in the A2 assistant software, I can only see my stick channels, F-Mode switch, and gear switch reacting. Gimbal dial or any other buttons/knobs on the controller are reacting with activation on the LB2 controller. SO I can't even operate gimbal tilt. I will draw a diagram now of what I have and post it.

Here is what I have currently. I did finally get it to where I can see that the gimbal tilt dial is working in the A2 software and I mapped it for tilt, but it still does not actually tilt the gimbal when operated. And when trying to map the "Go Home" button, I see no reaction from it in the A2 software (Is there a chance it is only seen when the unit is actually flying?). I followed your video linked above, and then this one: . I am beginning to think that I may just be missing something in the software settings to get the gimbal tilt working. The shutter/record controls are next. Also, I have no video feed to my tablet, but I am getting battery voltage reading on my tablet, so some of the transmission is working at least.

I can now see the gimbal tilt controls working in the A2 software, but it doesn't actually control gimbal tilt... Video showing what I mean:

NFA Fabrication Posted at 2018-1-19 21:38
I can now see the gimbal tilt controls working in the A2 software, but it doesn't actually control gimbal tilt... Video showing what I mean: https://www.youtube.com/watch?v=wsaMWwBRvgk

What are the channels mapped to, is it based on the transmitter or the output of the transmitter and  in turn the flight controller? You may need to map it differently. At this point there's a disconnect between the flight controller and the gimbal, although the gimbal is stabilized. Has the gimbal been calibrated? Does it show up in the app? Have you gone through all the menu's in the configuration relating to it?

Good to hear you're making progress. Check wiring from the gimbal to the flight controller, or is it only to power and the IMU?

HyperSpectral Posted at 2018-1-22 06:24
What are the channels mapped to, is it based on the transmitter or the output of the transmitter and  in turn the flight controller? You may need to map it differently. At this point there's a disconnect between the flight controller and the gimbal, although the gimbal is stabilized. Has the gimbal been calibrated? Does it show up in the app? Have you gone through all the menu's in the configuration relating to it?

Good to hear you're making progress. Check wiring from the gimbal to the flight controller, or is it only to power and the IMU?

Here is what I have right now if this helps:

I think this will answer your above questions. The one I have not done is calibrate the gimbal, not sure how to do that yet, but it sounds like something I should be doing after it is communicating properly with LB2?

NFA Fabrication Posted at 2018-1-22 11:57
Here is what I have right now if this helps:

I think this will answer your above questions. The one I have not done is calibrate the gimbal, not sure how to do that yet, but it sounds like something I should be doing after it is communicating properly with LB2?

edit: Try mapping the mode channel and changing modes in accordance with the left description of H.Free, reset, and H.Trace

I'll look more in depth into this when I have a moment but some quick searching resulted in this thread:
https://forum.dji.com/thread-13194-1-1.html

Might not be as direct as using the DJI applications, but dont take my word for it as I haven't worked with the A2 much

Looking at your video it's strange, but good, that its reading all your inputs. You have a GCU for the Z15 correct? We have the same module and I'm wondering if you connected something wrong within the wire that goes from the GCU to the camera, or from the GCU to the IMU

Try turning your camera on while trying to move the gimbal, sounds weird but our Z15 wouldn't work one time when our canon dslr wasn't on. Do you have any hdmi feed, by the way?

Can you confirm there's a 4 pin CAN cable running from the PMU to the GCU? Also confirm for me that you used the Zenmuse software and updated through that, not assistant
Found a DJI support thread with this, maybe it'll help:

HyperSpectral Posted at 2018-1-22 12:34
I'll look more in depth into this when I have a moment but some quick searching resulted in this thread:
https://forum.dji.com/thread-13194-1-1.html

I read over that thread, I didn't see anything too applicable to my issue. I do have the GCU installed, and the CAN-BUS cable from it goes to the CAN-HUB which is plugged into the PMU for the A2 FC. Is there a way to plug into the GCU to see if it is seeing the CAN-BUS system form the other items on the S900?

NFA Fabrication Posted at 2018-1-22 12:49
I read over that thread, I didn't see anything too applicable to my issue. I do have the GCU installed, and the CAN-BUS cable from it goes to the CAN-HUB which is plugged into the PMU for the A2 FC. Is there a way to plug into the GCU to see if it is seeing the CAN-BUS system form the other items on the S900?

I added some more to my previous post as I was reading things, might want to check what I said about modes.

I don't know of a way to plug into the GCU and check, unless you get into oscilloscope level interpretation of the signals lol I'd start by messing with the modes, and the calibration procedures and see if you can even get the gimbal to calibrate. IMU should be calibrated first btw

OK! Huge step forward, I plugged into the GCU via USB, and found there were 2 updates! I swear I already went over every module on this thing and updated everything, somehow these got missed or didn't go through correctly. Now that these updates are done I now have shutter control and gimbal tilt control! All I am missing now is video feed, and I am wondering if maybe that has to be turned on in the GH4 camera itself? Looking into that now...

Side note, I have a red light on the front of the Gimbal with camera on and connected...

Well, looks like possibly more bad news. I looked through the Z15-GH4 maual, and there is no mention of a solid RED indicator meaning anything. I searched, and found this thread suggesting I may have a bad HDMI board. I seriously can't win with ths thing.

https://forum.dji.com/forum.php? ... p;extra=#pid1145685

NFA Fabrication Posted at 2018-1-22 14:15
Well, looks like possibly more bad news. I looked through the Z15-GH4 maual, and there is no mention of a solid RED indicator meaning anything. I searched, and found this thread suggesting I may have a bad HDMI board. I seriously can't win with ths thing.

https://forum.dji.com/forum.php?mod=viewthread&tid=129774&page=1&extra=#pid1145685

Sounds like you're getting a first hand look at the biggest issue that will plague the manned and unmanned aviation industry for decades, human error

About the Z15, pretty sure ours is red when its on but I cant tell you that for sure..

Have you toggled the settings for video feed in the DJI go app yet?

Don't blame the system yet, verify your camera is set up to output HDMI correctly.

HyperSpectral Posted at 2018-1-22 14:31
Sounds like you're getting a first hand look at the biggest issue that will plague the manned and unmanned aviation industry for decades, human error  

About the Z15, pretty sure ours is red when its on but I cant tell you that for sure..

I tried, but I don't fully understand what people are saying as they always describe it like I have done it 100x. This very likely could be my issue, but the selections in the app aren't very clear as to what I am actually changing.

NFA Fabrication Posted at 2018-1-22 14:35
I tried, but I don't fully understand what people are saying as they always describe it like I have done it 100x. This very likely could be my issue, but the selections in the app aren't very clear as to what I am actually changing.

You're using DJI Go 4? I haven't worked with the S900 and A2 so give me an idea of what app you use to fly?

In DJI Go 4 it's the video transmission page, then you toggle the hdmi/ext buttons back and forth until you get your stream to show up.

HyperSpectral Posted at 2018-1-23 06:18
You're using DJI Go 4? I haven't worked with the S900 and A2 so give me an idea of what app you use to fly?

In DJI Go 4 it's the video transmission page, then you toggle the hdmi/ext buttons back and forth until you get your stream to show up.

Yes, using DJI 4, and also did that setting. I think we are the point that I have a bad HDMI board in my gimbal however. It has a solid red light on it, and every thing I have found on that has ended up being a bad HDMI board. Appears to be fairly common.

NFA Fabrication Posted at 2018-1-23 07:30
Yes, using DJI 4, and also did that setting. I think we are the point that I have a bad HDMI board in my gimbal however. It has a solid red light on it, and every thing I have found on that has ended up being a bad HDMI board. Appears to be fairly common.

That's unfortunate to hear, I suppose that's the gamble when buying second hand. Hopefully it's not too expensive

Ok..so the red light you are getting is on the bottom of the gimbal right? Not the LB air unit? If so I’ve seen a couple of issues...one is the above bad board. The other is what I went through but it was a LB 1..but same problem...you need to make sure your “appeture” switch is “open”...if it’s in the closed position it won’t let the video through...it took me forever to figure it out...I also had it mapped to a 3 switch instead of a 2....lastly, are you trying to operate as a single or a dual radio set up...?

NFA Fabrication Posted at 2018-1-22 13:26
OK! Huge step forward, I plugged into the GCU via USB, and found there were 2 updates! I swear I already went over every module on this thing and updated everything, somehow these got missed or didn't go through correctly. Now that these updates are done I now have shutter control and gimbal tilt control! All I am missing now is video feed, and I am wondering if maybe that has to be turned on in the GH4 camera itself? Looking into that now...

Side note, I have a red light on the front of the Gimbal with camera on and connected...

Yes...you have to have the camera turned on

Single operator, and nothing but the camera lens was purchased second hand. By aperture switch, do you mean a camera or Lightbridge setting? Thanks for the reply!

NFA Fabrication Posted at 2018-1-23 09:59
Single operator, and nothing but the camera lens was purchased second hand. By aperture switch, do you mean a camera or Lightbridge setting? Thanks for the reply!

Ok..I have to o do this by memory from work....do you have your Aux1 and Aux 2 from your GCU mapped to a channel? I mapped my Aux 1 to a switch and use it for Aperture. (Aperture open/closed) Closed will give you the red led.  I mapped Aux 2 to a 3 position  switch which is your camera down, camera straight or camera fpv..I think I saw your comment that your camera defaults down...in my set up I run through my 3 position to set the camera...you should also see this In your LB Assistant....if ya got nothing better to do try that..if might help...but, disclaimer, my rigs are set up for 2 person operation however the mapping should be the same..just on mine the camera is mapped to a second radio......I’ll see if I have a diagram when I get home