I am working on a short writeup about Meshtastic. Basicly Meshtastic is an off-grid messaging system that uses low cost hardware. I’ve been playing with it for a little while. I am still setting some stuff up, but if you would like to join my MQTT server for it and connect to more people, use the following credentials when setting up MQTT on your nodes.
Address: home.danielmaat.net
Username: public
password: meshtasticisfun
Enjoy!!!