3+km HD FPV system using commodity hardware

Hi

Over the last couple of months I have been working on a project that might be of interest to you: https://befinitiv.wordpress.com/wifibroadcast-analog-like-transmission-of-live-video-data/

Basically it is a digital transmission of video data that mimics the (advantageous) properties of an analog link. Although I use cheap WIFI dongles this is not one of the many "I took a raspberry and transmitted my video over WIFI"-projects.

The difference is that I use the cards in injection mode. This allows to send and receive arbitrary WIFI packets. What advantages does this give?

- No association: A receiver always receives data as long as he is in range

- Unidirectional data flow: Normal WIFI uses acknowledgement frames and thus requires a two-way communication channel. Using my project gives the possibility to have an asymmetrical link (->different antenna types for RX and TX)

- Error tolerant: Normal WIFI throws away erroneous frames although they could have contained usable data. My project uses every data it gets.

For FPV usage this means:

- No stalling image feeds as with the other WIFI FPV projects

- No risk of disassociation (which equals to blindness)

- Graceful degradation of camera image instead of stalling (or worse: disassociation) when you are getting out of range

The project is still beta but already usable. On the TX and RX side you can use any linux machine you like. I use on both sides Raspberrys which works just fine. I also ported the whole stack to Android. If I have bystanders I just give them my tablet for joining the FPV fun :)

Using this system I was able to archive a range of 3km without any antenna tracking stuff. At that distance there was still enough power for some more km. But my line of sight was limited to 3km...

In the end, what does it cost? Not much. You just need:

2x Raspberry A+

2x 8€ wifi dongles

1x Raspberry camera

1x Some kind of cheap display

Happy to hear your thoughts/rebuild reports :)

See you,

befinitiv.

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            • Ditto on this point - could someone break this down for the linux/RPI amateurs! Thanks :)

        • Randy, is 2.4G used as RC in your setup?
          • Developer

            Eric,

            Yes, I just used a regular Futaba 2.4Ghz tx/rx.  I haven't noticed any interference on the RC controls themselves so far.  I haven't tested whether the RC interferes with the video yet.

            • I think the interference will not cause any noticeable effect to your RC if the quad is not far enough from the tx. RC will basically do some kind of checksum and drop the bad packets. I guess the interference will cause packet errors and reduce the range.

              Is 900m your RC max range? ;-)
              Welcome to nginx!
  • Has anyone tried TP-LINK Archer T2UH ?

    Its MT7610U chipset is apparently similar to RT2860 chipset which apparently:

    Reply by Tommy Larsen on May 30, 2015 at 1:54am

    Check this link:

    http://ubuntuforums.org/showthread.php?t=1242285

    that says it can be run in monitor mode.

    • Monitor mode didn't work for me in Linux with that card.
      • Malkauns, thank you very much for the info

    • I tried it and couldn't get it to work on the pi.

      • Thank you for the feedback Tobias, appreciate

  • just tried the CSL dongles on a few 2.4GHz channels. When I have the taranis anywhere within 50cm of the receiver and turn it on the video gets massive artefacts. So if we want to keep using 2.4 for RC control we need to find a good 5.8GHz wifi dongle. Has anyone tried the ALFA AWUS051NH?

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