👍👍👍

Just showing the waterfall chart (no further data processing than the visual) would be of great help during drone races (8 pilots in the air on 5.8Ghz band). So for over the FPV analogue range of 5.7-5.9Ghz (resolution of 20mhz?) - would there be a solution with an RTL-SDR dongle and a downconverter? Or would the HackRF still be the cheapest path if you just want visualization (RX)? What would you do?

@cemaxecuter7783

3 жыл бұрын

Great point and now you have me thinking maybe a modified Pluto would be a cheap alternative. The Pluto SDR doesn’t ship with the 5.8ghz range available but the hardware supports it. There’s a bunch of videos showing how to modify it. An example here www.rtl-sdr.com/adalm-pluto-sdr-hack-tune-70-mhz-to-6-ghz-and-gqrx-install/ I do want to get a Adalm Pluto and try this. If I get one I’ll make a video. Plus I hear there’s great support for it within sdrangel.

@cemaxecuter7783

3 жыл бұрын

It’s got the bandwidth you’re looking for and it’s about $150. Just needs the modification done.

What hardware are you using to receive the signal?

@cemaxecuter7783

7 ай бұрын

I think in this video, blsderf, but it can be easily done with the hackrf too.

Is color demodulation also possible ?

@cemaxecuter7783

2 жыл бұрын

That’d be awesome but not possible with this method. I will say that in later testing I got an extremely clear and smooth picture but adjusting sample rate/bandwidth etc. I was really surprised.

I have SDR Angel Software and SDR Uno Solfware work's with both SDR Play RSP DX and a Adalm Pluto SDR,

@cemaxecuter7783

2 жыл бұрын

That’s awesome, I’m keeping an eye out for the v7 sdrangel deb package. I hope SDR Uno will come to Linux some day!

i wish we can broadcast analog channels with this thing

@cemaxecuter7783

3 жыл бұрын

github.com/fsphil/hacktv

@Hex-Mas

3 жыл бұрын

@@cemaxecuter7783 hacktv Even works with a rpi4 and hackrf. But wish i can do DTV.

@cemaxecuter7783

3 жыл бұрын

One of these days I want to make a pi distro. There’s so much that can be done with the pi too!

@Hex-Mas

3 жыл бұрын

@@cemaxecuter7783 I would love to play with that.

@cemaxecuter7783

3 жыл бұрын

You should be able to do it with gnuradio, I think I looked at making a video on this. I’ll have to see if I did but here’s a quick article about it myriadrf.org/news/digital-video-transmission-using-limesdr-gnu-radio/

To make it clear no way get the basic FPV stream on the Portapacks inbuild analog TV feature. Are new to this, but tried with my unit and just going directly to the FPV bandwidth looks something like this .i.imgur.com/RCGPbXD.jpg and on the analog feature like this i.imgur.com/4gLFe8h.mp4 definitely data there, but likely not enough tools to synch it.

@cemaxecuter7783

3 жыл бұрын

Love the setup! I really need to get a portapack. I honestly didn’t know it had that feature and it almost looks like you got it tuned. I have what looks like that same exact camera you have laying there. You’d think though if it has that analog feature it should be able to view it. Does it give you any options similar to sdrangel?

Why is the video in black and white though?

@cemaxecuter7783

8 ай бұрын

Limitation on SDRAngel’s demodulation mechanism most likely. Good question though.

Any latency?

@cemaxecuter7783

Жыл бұрын

I don’t recall it working as well as SDRAngel. SDRAngel was real-time and really clear. I’ll have to give SigDigger another try, but from memory I didn’t have as good as result at the time.

@user-ny3km4qb6k

Жыл бұрын

@@cemaxecuter7783 thank you very much for the fast response :)

Is it possible to demodulate DJI Mavic video streaming?

@cemaxecuter7783

3 жыл бұрын

Not with this technique. Pretty sure DJI uses digital and/or some other techniques. If you google analog fpv camera you’ll find some for like $15 and they’re normally sold for racing drones.

@digus

3 жыл бұрын

I believe the consumer drones like mavic still use regular Wi-Fi (as opposed to lightbridge on the pro level) - but you’d need more than this. Breaking the encryption would be the first step, so not sure it’s worth the effort in most cases. If you have the key, something like dragonfly for android could work.

@cdplayerman

3 жыл бұрын

​@@digus I see. I'm currently doing a research project on DJI Mavic 2 Pro, but I'm stuck at demodulating its signal which I believe DJI is using OFDM.

@Willam_J

3 жыл бұрын

TheEpicProduction - Before trying to receive/demodulate/decrypt any radio source, I look for the FCC ID, which will be on the transmitting device. Then, I just enter it into this website: fccid.io Once you’re at the FCC information, download the ‘RF Test Report’. It will tell you everything that you need to know, except for decrypting an encrypted signal. I know that DJI isn’t encrypting their video signal. It’s simply a digital video feed. My Yuneec drones use the same format. I can watch the video through a browser, on my laptop or iPad, with an RTSP connection. This should get you started. en.wikipedia.org/wiki/Real_Time_Streaming_Protocol You can also just Google how to receive the video, and then go from there. I hope this helps!

@digus

3 жыл бұрын

TheEpicProduction Oh wow, that’s cool - so being the “pro” model, I’m pretty sure you’ll have ocusync to deal with. I believe it’s using some type of spread spectrum frequency hopping techniques. I’m no expert but FHSS could certainly look a lot like ODFM at first- kind of like moving around quickly, vs multiplexing on different frequencies..? As far as I know, neither DJI protocol has been defeated publicly, yet. I just have an old P4P and do not really stay on top of these things any longer, so I could be off on some of this. @William J is absolutely correct that the FCC site is pretty much always the best place to start. So while they may all be using RTSP on the inside, the difference between a mavic Air (WiFi) and a Mavic pro (ocusync) will likely be quite a bit different in the (propriety) wireless encapsulation technique.