Working with mavlink in Java

Ground Control Software
1

I am starting a new project to experiment with swarm control in Java. So to begin, I am running five SITLs of Copter 4.0 in five separate docker containers.

I am trying to figure out the best way to interact with these SITLs (and later real copters) through Java. I have tried using mavsdk_server https://github.com/mavlink/MAVSDK but it actually causes the SITL program to crash with a floating point error when I connect. So the MAVSDK project seems a bit young and I need to use something more robust. Would any of you have suggestions on how to interface with mavlink over a network in a Java program?

Any suggestions would be great, thank you.

2

pymavlink can generate Java bindings for you. Try using that. There is a PR that improves pymavlink https://github.com/ArduPilot/pymavlink/pull/341

3

There’s also this: https://github.com/dronefleet/mavlink
which might be worth looking at.

4

For whoever comes behind me to read this, I have begun using dronefleet/mavlink which has worked out very well.

5

Hello Asher. I’m relatively new to drones and Mavlink. Could you please help on how I can use Dronefleet Mavlink in Java from GitHub - dronefleet/mavlink: A Java API for MAVLink communication.
I am trying to create an app for precision dropping of an item from drone and will use these params received from Px4 and use them for deciding the target.
I would be glad if you help me in this regard and get me going?
Appreciate your kind help and support

6

Configure pymavlink to generate java code output and run it.

It will produce a java library that is able to talk mavlink.

All your code needs to do is call the library appropriately in order to control the drone(s)

7

Thanks for your reply. Please clarify the pymavlink generator you are referring to is this:
https://mavlink.io/en/getting_started/generate_libraries.html

Using this I need to generate Java version for the dialect and when in android application how I need to call the generated java library and get the result I desire? For example, if I need alt data from Px4?

Appreciate your help

8

Yes, that is what I meant.

The generated library contains java functions that you must call in order to control the drone. The function names are mostly self explanatory.

For Android programming there are many on-line courses. That is out of scope from this forum.

1 Like
9

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Hello, these are the files generated from mavgenerate.py. I was unable to find any online course that may guide me in the right direction of how I can use these files.
Could anyone please guide me on how I can use these generated files in android studio. Also, is there any other way to communicated with px4 using MavLink with Java.

10

Hi.

If you are a little flexible with using Kotlin/JVM instead of Java, then you can even use mavlink-kotlin.