Bad mix?: T14SG, DJI LB, Movi M5 w/DX7s GH4

Discussion in 'MōVI M5' started by Ben Clark, Apr 22, 2015.

  1. Ben Clark

    Ben Clark New Member

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    Please excuse the post if I have duplicated. I have read all 27 pages and am still stuck. In the process of moving to the S1000+ (A2+LB). Purchased the DJI LB and Movi M5/DX7s at the same time and now concerned they will conflict on 2.4 bandwidth. Have had my fair share of crashes (pilot and ESC induced) but now I have more expensive kit in the air I would like to get this right. Flying in single operator/majestic mode only is an option but I have some very awkward shots to get and would like to use the Movi operator mode if at all possible. Never tried SBUS decoding but assume that I am about to have to... Any recommendations? Another LB system for the Movi? Or should I just get realistic and use the LB with GoPro3 for FPV and go get a converter & 5.8 video tx and forget about Movi control? The solution does not have to be pretty - thanks in advance.
     
  2. Shaun Stanton

    Shaun Stanton Active Member

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    It looks like your setup should be fine as a single pilot op. It looks like you will not be using the Spektrum radio on the DX7. You will be controlling the copter thru the LB system with through air module. Looks like you connect the Spektrum radio to the Ligthbrige ground station without turning the radio on. Once the cord plugs into the training port the spektrum will turn on w/o the radio broadcasting and will send its signals to the LB. The LB sends flight command signal to the LB Air module the LB. Then the CAN bus decouples the signal into the A2. So the radio controlling the copter is the light bridge. My only take is that the 7 channel might not be adaquate. A DX9 or some other Radio might be better. Futaba seems more poised for DJI products. Spektrum works. Not sure if I am a big fan of them anymore. The DX9 has under grip sliders to make gimbal control easier if you stay with them.

    For two person ops using the LB there might be interference since the system is on 2.4. They recommend in your scenario using a independent gimbal control to use a 5.8 video TX of course this kind of negates the whole point of using LB. I am going to try LB flying with my Ronin and using a Futaba setup. Futaba does active frequency hopping supposedly to find the cleanest channel. We shall see. The test will be done with gear down in an empty field.
     
  3. Ben Clark

    Ben Clark New Member

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    Thanks Shaun, I agree the Spektrum won't be adequate for flight control. So I have the Futaba T14SG hooked up (non-Tx mode) to the LB Ground station via Training port/cable with the 12 channels via Training enabled. Is that part ok? The Spektrum DX7s comes with the M5 so prefer to dedicate that to the Movi dual operator control if there is a way - SBUS decoding? I also have a Spektrum DX8 from Xpro Heli XP2 but assume that the DX7s's 7 channels will be more than enough for the Movi M5 controls? Maybe not? For flight control I need more channels than the above Spektrum's will allow so have mapped channels on the Futaba T14SG and on the LB & A2 as follows:

    Channel 1: AIL J1
    Channel 2: ELE J2
    Channel 3. THR J3
    Channel 4: RUD J4
    Channel 5: GEAR SG
    Channel 6: RATES SB
    Channel 7: Flight (GPS Attitude, Attitude, Manual) SE
    Channel 8: Go Home SD
    Channel 9: IOC SC
    Channel 10: Cruise Control SA
    Channel 11: Unused. Can I use this for Point of Interest?

    You correctly assumed I do need to be able to go 360 in dual operator mode with no cable tangles so I assume that the Video tx will have to be something tied to the gimbal bars above or below the camera. Still unsure as to what will work for Gimbal operation alongside the LB 2.4GHz?
     
  4. Shaun Stanton

    Shaun Stanton Active Member

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    You are if you going to use the gimbal independently with full 360 you will need the gimbal to be on its own thing. Without a FC It does not look like the LB works on the gimbal independently because of the CAN-BUS with the exception of a Ronin which they don't even mention. The only way see to trick the system would be to buy a flight controller like a NAZA just to be a bridge for the gimbal control and use it independently with caution that the 2.4 may induce interference with the LB to the Futuaba bus on the AC. The Naza would be pluged into the CAN-Bus and D-BUS. Not sure if the MOVI will support this though since it just uses the Spectrum satellite or the Sbus. I don't know if the FC would pass through this info to the SBUS. My thought is that it will not w/o some sort of PWM to SBUS converter like this dongle.

    http://www.hobbyking.com/hobbyking/...ecision_PWM_PPM_SBus_Signal_Converter_V2.html

    It seems like it will be very very cumbersome unfortunately unless someone has cracked a magic trick on it. I cant find any info that the LB can be used w/o an FC unless its going into Ronin.

    Looks like alot of stuff going on with the LB and its dependence on a DJI FC system. Since the LB is using its own system to talk to the FC which in turn is controlling the stick commands to the gimbal like a Zenmuse it does not look like a direct plug and play to other gimbals like MOVI without a bit of work. What would end up happening is that you would,

    1. Connect the A2 completely independent of the gimbal. It has no effect to gimbal.
    2. Purcahse a stand alone DJI FC with gimbal control like a standalone NAZA V2. This is just a slave to send signals to the MOVI from the LB thru a PWM to SBUS converter.
    3. PWM to SBUS converter to talk to the MOVI from the NAZA.
    4. In the NAZA you would need to disable any gimbal compensation gains and let it just pass the appropriate drive signals. This is so the NAZA is not sending the compensation commands that the MOVI probably does better. MAP in NAZA the appropriate AUX channels those will also need to be connected to the PWM converter.
    5. Connect to MOVI and tweak.
    The NAZA I think sends 5 or 6 volts through its PWM's.

    Not an elegant solution but it is one that will in theory work.

    DJI you gota love them and hate them at the same time.

    Good luck.
     
    Ozkan Erden likes this.
  5. Ozkan Erden

    Ozkan Erden Distributor

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    I wouldn't use LightBridge with any other 2.4 GHz system unless you do as Shaun described. As for Shaun's solution, you need to buy another controller to make it work which is another investment.

    Personally, I wouldn't use Lightbridge on your system. I'd sell it and buy a video transmitter like Amimon Connex which is 5.8 GHz, use Futaba on the copter and Spektrum on the Movi and live happily after :)0
     
    Shaun Stanton likes this.
  6. Ben Clark

    Ben Clark New Member

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    Thanks Shaun, really appreciate the detailed solution explanation - I was looking at the Ronin for exactly that reason but ended up going M5. I could re-purpose my Naza from an older XP2 but still worried about the 2.4 clashes. It's a cheaper solution but might cost me in the long run.

    Hi Ozkan, thanks also, I noticed they (Amimon) just released a longer range version of Connex at NAB. Can I ask what Video solution do you use on your far more serious camera set up(s)? Living happily ever after does sound like the way to go. Might have to move the LB to the P2.
     
  7. Shaun Stanton

    Shaun Stanton Active Member

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    Thats a pretty slick system, well within a reasonable price point unlike a teradek or paralinx. I may be looking to do that myself. Especially carrying a Red or BM with a SDI/HDMI converter.
     
  8. Shaun Stanton

    Shaun Stanton Active Member

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    The 2.4 might be a concern for sure. Probably not worth the risk. I like the tx that Ozkan pointed out, I think it is a real good solution all around for this stuff. As for the Ronin its a real beast about 4 pounds heavier than the M5. My highly modified heavy lifter barely flies it on a 10,000 MaH battery. I can get 7.5 to 8 Min with the Ronin and a black magic 4K with two 8000's in parallel. The ESC's are really working hard at this point. Of course I am flying a Coaxial on the old cinestar medium lift frame for compactness. If I fly my alexmos Movi ripoff I can get 8 Min on the 10,000 with the BM. Unfortunately the Alexmos is not as friendly for rapid adjustments on set but it will fly the RED fine when I am there to tweak it.
     
  9. Ben Clark

    Ben Clark New Member

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    Thanks Shaun, I am not getting much more with one new 16,000 and the M5/GH4 combination. What do you run the voltage down to on an average flight? Having a Red makes up for lack of flight duration - very envious. Have contacted Amimon and waiting for their response/advice. Would you mount their air side unit to the Gimbal?
     
  10. Shaun Stanton

    Shaun Stanton Active Member

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    No problem. You should be getting some real good flight times out of a flat 8. You might consider changing motors so you can put different props on. U5's with 16 inch props should giver you tons of flight time if your 1000 will is long enough to handle 16's.. I was looking at what Dave King was getting in the coaxial cinestar page. He is getting high 20's on his flat 8 and 12 to 15 on his coaxial. Thats one of the problems I have with buying the out of the box solutions from DJI other than Phantoms their motors only allow you to use DJI props which do not give you much flexibility for different flying conditions. For example I fly a pretty thick pitch prop because I live in New Mexico where our air is thinner at a filed elevation of 5000-6500 feet. You might consider resercjing the different forums to see what other people are doing with their DJI birds to get more time out of them.

    As for your question on the air unit. I would find some place on the gimbal if you can. Or else mount it on the camera. I beloeve FF has more brackets and places to mount stuff on the MOVI now. Back in the day when all of us were flying the Movi's "civil war era great grandfather" the Cinestar Radian gimbal the only place to mount things was on random spots with zipties. I find my self mounting most of the gack on the Blackmagic camera because its such a wide body with the real estate. My Ronin hangs really low where I would need long cables to attach things to the gimbal frame.

    Hope that helps.
     

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