GoPro Start/Stop

[rmklaw]

Is there any way to start/stop the video or take single pictures while in the air? I am purchasing a Phantom 2 with gimbal, and would like to have the start/stop capabilities of the Vision.

[jamesb72]

I replied to the other copy of this in 350QX forum, so copying below for Phantom specific version.

Using timelapse mode is fine you can take a still picture every x seconds through your flight, if you have a H3B/H3B+ you can film 720p/60 or 1080/30 video AND take still pictures every 5 seconds at the same time which I use and really like, so you have the best of both worlds.

If you have video editing software (windows movie maker 2012 is free and works great), you can just video the entire flight from power on to landing and just edit out the non-flying or boring bits very easily, so thats actually easier, and its what I mostly do now, as the smartphone is a kerfuffle.

The Blade 350QX wifi bulletin states not to stream video across wifi - ie using the gopro app with video preview enabled. Bulletin specifically states its OK to start/stop the camera using the wifi remote control - I am pretty sure using the app to start/stop is identical, its the streaming video/preview you need to avoid, so just go into settings and untick preview before flying (I use it before flight to line up camera, then switch off before flying).

The DJI Important notice for Phantom v1.1.1 (I am guessing warning is the same for all models) is worded differently to the Blade bulletin, but both use 2.4Ghz RC using frequency hopping so should technically be the same:

"Never use the DJI Phantom Quadcopter with your GoPro camera when you have the GoPro Wi-Fi system turned on. The DJI Phantom's and the GoPro camera's WiFi run on the same frequency, so if you use them together when both Wi-Fi system is engaged, the DJI Phantom's transmitter will lose the ability to communicate with the DJI Phantom Quadcoter. Whenever this happens, you will not be able to tell the Phantom where to fly. This may result in loss of property or damage to your equipment."

I believe this is a commercial/marketing issue, DJI sell the Phantom 2 Vision with remote control camera so the gopro is a direct competitor, and they would rather you buy their camera, they also sell the H3-2D gimbal which incorporates gopro start/stop control, so clearly they want to make this more desirable than the chinese gimbals which cost 1/4 as much and work pretty much the same (except the start/stop feature) I don't believe this is actually a genuine risk if you use gopro with streaming disabled as people have been doing for a long time with the phantom.

There are two issues you need to be aware of before using gopro/wifi on any multirotor with GPS controller.

1. When streaming video over wifi from the gopro onboard, the gopro will be transmitting a wifi signal very close to the RC receiver, which in normal flight will be several hundred metres from its transmitter so risks swamping. This shouldn't actually be an issue for remote control start/stop control only (smartphone app with preview disabled, or using the Gopro remote control to start/stop camera/take stills).

2. There is a known issue with some gopro camera's producing RF noise when recording video even with wifi disabled, and this causing GPS problems for all multirotor controllers (including the Naza in Phantom, and the 350QX GPS receiver, and any others), this RF interference seems to come from SD card or battery during video recording even with wifi disabled, so you need to be careful to check your gopro is OK with your phantom/350QX on the ground, obviously losing GPS during flight will change behaviour, you won't have return home or GPS hold or IOC, so you need to be aware of this issue, and if anything strange happens be ready to switch to atti mode (or manual/agility) to fly back.

My advice would be to test thoroughly on the ground, time your GPS lock with gopro mounted but switched off wifi off, then time GPS lock with gopro recording video wifi off, then time GPS lock with gopro recording video with wifi on. If the times are similar you are probably fine to use gopro wifi WITHOUT video streaming, if it takes much longer to get a GPS lock or you cannot get a GPS lock with gopro running thats your answer. People are screening the gopro's using foil tape and other methods - plenty of info on the forums if you have a noisy gopro (or try to exchange it and get a good one, and you should then be able to use gopro with no extra measures required).

Anyone who thinks 2.4Ghz can't operate nicely with other devices clearly hasn't flown at a club, or flown near a wifi router etc, as ALL 2.4Ghz equipment from wifi routers to gopro's to bluetooth headsets to 3G mobile phones to RC radio gear has been designed to play nicely together in all normal situations, providing common sense is used.

The supplied DJI transmitter/receiver uses the Futaba FASST system, which changes frequency hundreds of times a second so it will only use each frequency for a fraction of a second, if there was strong interference on any one channel (ie your wifi signal from gopro to your smartphone), it would pass through this so quickly you would never even notice.

If you use a DSMX transmitter (Blade 350QX or any modern Spektrum receiver ie AR8000 with any modern Spektrum transmitter ie DX8/DX9/DX18), this also uses frequency hopping, the tx/rx step through a 24 channel hopping sequence multiple times a second, so again if any one frequency was swamped this would not be an issue.

Even if you have an old school DSM2 transmitter (original DX7, or an old DX6i) this will select two free channels at startup (if your gopro wifi was on it should avoid those channels and pick two of the 62? channels), and ensures these two channels are spread apart, so again if you had a interference on one channel (flying over a house with a wifi router, or your gopro wifi connection on a single channel), it should not affect both DSM2 channels so you should still maintain control.

In any case of interference, if the receiver loses frames repeatedly due to interference, it will go into failsafe which you should have setup to return home/autoland safely, hopefully you would recover RC signal as soon as the quad flies away from source of issue so you can recover control (make sure you know how to do this beforehand, and obviously unless you have gopro streaming on and its attached to it but that should be easy to avoid).

[Tahoe Ed]

Or you can put a H3-2D on a Vision and use wifi without issues. Not sure that I want to do that yet. I am having fun with both the P2 and the Vision but the prospect is interesting.

[jamesb72]

The cost is eye watering My Phantom1 and brushless gimbal together cost less than this h3-2d gimbal on its own !! Also does it support start/stop NOW? - features page suggest its planned for future firmware upgrades:

http://www.dji.com/feature/zenmuse-h...al-feature/#a3

"The H3-2D gimbal is designed for the GoPro Hero3, and remote start/stop shooting, video transmission (video downlink required), etc of the GoPro Hero3 will be supported by future firmware upgrades."

I am still convinced the DJI wifi ban is more of a marketing plan for their stuff than an issue with 2.4ghz and their FASST receivers. The Phantom2 Vision uses 5.8Ghz for RC control (which may not be great if you are flying around video transmitters which use wide analogue frequency bands) - the Phantom2 I believe uses 2.4Ghz for RC, surely if DJI recognised 2.4 was so unsuitable for RC they would put 5.8Ghz RC on everything (and reduce range considerably as a result) !!

[setishock]

It's odd the choices they are making. The switch to 2.4 for the video feed is because your smart phone can connect to the camera directly. But they surely could have made a better choice for the control link. The 900Mhz band is wide open.
The wireless remote for my LED strip controller is 433Mhz. Bands are open that aren't seeing much traffic that could be used. But however they went/go it still makes the setup proprietary. I personally don't care for that business model.
And for what they're asking for the new hardware, you think they would have scoped out some other options. It seems they are masochistic in a way. They seem to enjoy shooting themselves in the foot.

[jamesb72]

Originally Posted by setishock

It's odd the choices they are making. The switch to 2.4 for the video feed is because your smart phone can connect to the camera directly. But they surely could have made a better choice for the control link. The 900Mhz band is wide open.

I am guessing 5.8ghz and 2.4ghz are the only bands available across most/all countries, anything else (900mhz, 1.2ghz etc) vary from country to country which would be a big headache. Given they already have a wifi booster for the Phantom 2 Vision, that could easily bridge 5.8ghz to 2.4ghz, so I would have stuck to 2.4ghz for control and 5.8ghz for video, but clearly they must have looked into all options and decided this was best.

Weird that they stuck with 2.4Ghz for the control for the Phantom 2, you'd think they would go 5.8ghz for all control if they think its better

[setishock]

It would have reduced inventory and manufacturing costs considerably. Then all you'd have to do for a version 1 is replace the TX/RX package.
I like the ver 1 bird I fly, but you know, they really have me wondering what's going on with them sometimes.

[rmklaw]

Thank you for the thorough explanation jamesb72. I am waiting to receive my P2 and will experiment (on the ground). In the meantime, I am playing with my Vision. Another option is to purchase a FC40 and install a GoPro and the gimbal. In that case there would not be an interference issue. What I don't know is if the electronics in the FC40 is the same (version, features, quality, etc.) than in the Vision. It could turn out to be a cost effective alternative as a good AP platform.