Live aerial broadcast using DJI Phantom 2 Vision+ - Eric Cheng

Live aerial broadcast using DJI Phantom 2 Vision+

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I met up with a bunch of drone-flying buddies today to do another live broadcast test using a DJI Phantom 2 Vision+ quadcopter. It was a great success!

What is notable about this demo is that I’m using the latest beta of the DJI Vision iPhone app, which includes Ground Station. Ground Station gives you the ability to plan and fly autonomous, waypoint-driven missions using a satellite map overlay. During flight, you can take pictures, start and stop video, and tilt the camera up and down. This new version should be out soon.

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Many people asked how I was able to pipe a screen feed from my iPhone to a Google Hangouts On Air session. It doesn’t matter that I specified the exact gear necessary the first time I did a live broadcast, 2 weeks ago. I’ll list it out again, using… copy and paste! Hooray. But this time, I’ll include a handy picture:

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Here’s how it works. The Apple Lightning adapter outputs an iPhone screen mirror as an HD video signal over HDMI. The Febon168 HDMI grabber “card” (720p) version (actually, a USB dongle) is the ONLY device I’ve seen that can sync with and deliver to a computer the Lightning adapter’s HDMI signal without the user applying some sort of magic. Previously, I tried various Blackmagic devices (e.g., Intensity Shuttle) with no success. With the FEBON dongle, the iPhone video feed shows up on the computer as a standard UVC device, which Google Hangouts—and every other app on the Mac that can use a webcam—can use. Go to the settings when you are in a Hangout and choose the UVC device as the camera. Finding the FEBON dongle took a TON OF TIME. There is no useful information on the internet about how to successfully get an iPhone screen onto a computer in a way that supports Google Hangouts, especially when Wi-Fi is not an option (it is used by the Vision+ connection).

Obviously, the host computer will need an internet connection in order to broadcast Hangouts on Air. For internet access, I tethered to the Verizon LTE connection on my iPad Mini; this wasn’t ideal, but Stanford’s guest Wi-Fi connection wasn’t cooperating, so we had no choice but to use it. This is the source of blocky video.

The video feed was also mirrored on my local Hangouts display. This is normally done for webcams so people in front of a computer don’t get confused when they look at a video of themselves. I used Hangout Toolbox to reverse the video on my local display.

Audio was a bit more complicated. I wanted to be able to talk during the Hangout, so I paired an inexpensive Bluetooth headset to my computer and used it as the audio source. This allowed me to talk over the video feed, but had the wonderful effect of removing all of the bass from my voice (which is usually quite low). The audio also flickered in and out a bit as the Vision+’s Wi-Fi range extender blasted out a signal on the same frequency band. A wired headset would have been better, I think, but having a cable hang off of my head might have been annoying.

Are there any more questions about the setup? Please don’t ask me whether you can beta test the app or when it is coming out. I won’t reply.

Thanks to the crew who came to Stanford to hang out!

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Left to right: Scott Highton (panorama master), Steve Doll (graphic designer and 3D-printed micro-quad man), “Doc” Brown (Adobe playboy), Nora (Stanford geology), Romeo Durscher (NASA sun imager and awesome aerial photographer), Jerome Miller (needs to be converted to multicopters), George Krieger (drove 3 hours, only to miss the event), Pablo Lema (newly-reborn at GoPro), and me.