How does Mavlink work?

ArduCopter
1

Hello,

my goal is to build a drone which I can control remotely from my Mac via QGroundControl, I have seen that I can use WIFI as a connection but its range is pretty limited. But QGC also supports Mavlink which as I understand it right now is basically a normal (supported) rx on the drone and a tx which is connected to the laptop. Then there isn’t really any documentation on what rx and tx are supported does it only work with certain FCs how do I set it up to work on my laptop with QGC, is it diffrenent to connect the rx than if I would use a radio and how would I stream video to my laptop (this may not be Mavlink not sure), this is really confusing. Then I found this project on GitHub (GitHub - olliw42/mLRS: 2.4 GHz & 915/868 MHz & 433 MHz/70 cm LoRa based telemetry and radio link for remote controlled vehicles) which still didn’t help me really just that I now know a maybe compatible rx and tx.

So overall my question is “How do I use Mavlink” I really hope that someone can help with that, also regarding range im fine with 1km but more is always appreciated!

Thank you in advance!

2

It just requires a transparent serial data link 56700 baud to 1500000 baud.

Many of-the-shelf Modems get the job done and work fine. The Australian made RFDesigns RFD900x or the RFD868x are widely used for this purpose and have the range you want.

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3

Thank you for your reply!
I still have a few questions though:

  • How do I connect the tx to my laptop and do I need a radio?
  • How can I get video from my drone to QGroundControl?
  • Why are all the tutorials talking about coding yourself with mavlink? I just want to use my laptop as basically a radio.
  • And the modems you send there are pretty expensive, can I use a more normal rx and tx?
4

Just search for “Ardupilot telemetry radio”.
You will get all the information you need on how to connect the radio to the PC. it uses a USB connection.

There are cheaper radios but they either do not have the range, or they do not have the required data rate, or they do not have software.

These are telemetry radios, they will not allow you to transmit digital video.

You don’t need to code anything, just connect a joystick to the PC And the telemetry radio to the same PC. Then calibrate the joystick and the drone. That is it.

5

Thank you,
so there are commercial transmitters for this ok.
But what do you mean by by a joystick?
Could you please also tell me how I can get video this far?
Thanks

6

I am under the impression that you want to use your PC as a RC transmitter replacement. Operation Using Only a Ground Control Station (GCS) — Copter documentation

If that is the case you will want to use a joystick: Joystick/Gamepad — Copter documentation

For long range digital video transmission there are very expensive high datarate data transmission modems. High Definition Live Video FPV Systems — Copter documentation

Some analog alternatives are here: Video Transmitter Support — Copter documentation

You can use any one you want as long as it does not interfere with the GPS signals

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