@kimot Thank you for your comment & tips.

For those of you who want an extremely simple build, I've reduced it to just 5 parts: one 1-megaohm resistor (0805 SMD) one Arduino Pro Mini one Ra-01 LoRa module Male header pins Battery clips See photos.

I've added all the files manually so things should be there now (though I'd recommend grabbing things from github to preserve directory structure and get all the files).