What exactly is 4Gmetry?

Silvio,

I’ve been working on essentially the same thing for the past couple of months but mostly experimenting with various options, looking for the best (and practical) solution. I started by hacking a Nexus phone, replacing Android with Ubuntu. That proved to be way too unstable. I then switched to a Raspberry PI, which was more than enough to handle telemetry. I connected to the PX4 using TTL UART and wrote a redirector using TCP/IP, while inserting my own MavLink RSSI messages. For data transmission, I played with both cellular modems (a few different Huawei modems) as well as WiFi (Rocket M, point-to-point bridging). To solve cellular network addressing, I run my own DDNS server, which allows both ends to find each other. I’ve recently started working with video streaming (the original goal to begin with). The load was a bit too much for the Raspberry so I switched to an Udoo board (Quad core A9 at 1GHz). For the ground station, I’ve ported QGroundControl to iOS (and also Android for that matter though I can’t stand Java). All in all, I have telemetry working with 100% reliability but video is far from ideal. Today I found your 4Gmetry and it obviously caught my curiosity.

With that said, I’m trying to understand what exactly you’ve done. Have you written a software stack for handling MavLink telemetry along with (gstreamer) video streaming? If yes, where is it?

Thanks!

Indeed I have not run any of this outside a bench environment, and so far TCP/IP worked fine. I already had the code so I just plugged it in. Converting to UDP would be trivial though.

For Gstreamer simply install it and point it to your GCS

That's a bit vague to say the least :) I've been testing with the gstreamer tools with the intent to eventually build an application specific binary using its API (instead of piping data from the console). I'm also looking into OpenH264 and bypassing all that as I control both ends and don't need encapsulation.

None of that however answer my original question. I'm still trying to understand what it is that you've built and are calling 4Gmetry. Is it a software stack or just a concept?

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Volta Robots April 14, 2015 at 12:50am

Thanks Grub for sharing your adventures. TCP handles packet loss in a way that's not recommended for our goal; UDP is better. For Gstreamer simply install it and point it to your GCS. For any question please use this forum! Tnx S.
- Gus Grubba > Volta Robots April 14, 2015 at 8:00am
  
  Indeed I have not run any of this outside a bench environment, and so far TCP/IP worked fine. I already had the code so I just plugged it in. Converting to UDP would be trivial though.
  
  For Gstreamer simply install it and point it to your GCS
  
  That's a bit vague to say the least :) I've been testing with the gstreamer tools with the intent to eventually build an application specific binary using its API (instead of piping data from the console). I'm also looking into OpenH264 and bypassing all that as I control both ends and don't need encapsulation.
  
  None of that however answer my original question. I'm still trying to understand what it is that you've built and are calling 4Gmetry. Is it a software stack or just a concept?

This reply was deleted.

Volta Robots

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