Sending monitoring data from Arduino to MinimOSD

Hi all

I'm working on an RC project using an FPV setup to help when controlling an RC boat. The boat has data being monitored by an Arduino such as ambient internal temperature, engine RPM etc. and this needs to be overlayed onto the FPV camera footage.

For this I was hoping to use a MinimOSD board which I already have available. This enables fairly easy layout of the panel on the display, and is typically used with flight controllers such as Pixhawk, where it is just connected to the telemetry port. I believe when doing this MAVlink packets are used to send the data across.

From what I can tell, it seems I'm trying to do something like this video (however it has very little accompanying description).

What I'm trying to work out is how to send MAVlink packets from the Arduino to the MinimOSD. I'm struggling to find any resource explaining how I might do this and there isn't much documentation that I can understand (even though I'm hardly new to coding).

I've seen this thread which uses MAVlink but sending data to a Pixhawk. (The example compiled but only sent one character until I removed the FastSerial library - some people suggest it's not needed with the more recent IDE.) The outdated libraries in the GitHub repos didn't help.

Has anyone done anything similar, or come across any good libraries or guides? Any help with this would be much appreciated, as I'm not making much progress. If I come across a solution in the meantime, I'll post it here.

Thanks in advance