Getting an ethermega (essentially an Arduino with built in ethernet) talking to a Photon/Core

I’ve been doing a lot of reading on the forum this last half hour but am getting a bit more confused rather than less.

I understand the Arduino can’t do HTTPS therefore it can’t talk to the Particle Cloud directly.

But can it talk to the cloud using a middleman, perhaps like

I have an unused (for some years) ethermega I’d like to use to monitor my front door and for my .

The ethermega and the Core aren’t physically that near each other so I’d like to use the wider internet to get them somehow communicating. And it would be in the direction of ethermega–>Core rather than the other way around which would be a lot easier I gather!

The ethermega doesn’t need to get a response from the Core, it’s enough that it sends its message.

Your thoughts welcome. if it’s not possible that’s fine.

hmmm…looks like might be the answer I seek? Not sure if my Core can do BOTH Particle Subscribe AND communicate with this NATS server as well…
Guess I can but try!

Maybe even simpler is a UDP message sent from the EtherMega to the Core/Photon.
I’ll have a look for a simple library.

I’m going to give this a go tonight, before I do, can anyone comment on whether asking the Core to do BOTH UDP and Particle Subscribe/Publish is going to actually reliably work? Thanks