Have you ever heard of Meshtastic?
It’s a software that allows the creation of a mesh network in order to exchange messages and telemetry data via radio signal using the LoRa protocol, without the need for the Internet!
The LoRa boards that can be used with Meshstastic are really cheap and can be bought from a variety of sources (AliExpress, Lilygo.cc, Heltec.org, and Amazon).
Every board has different pros and cons: one could consume less power, thus making it compatible with a solar system, and another one could have a screen and a small keyboard so that you can use it like a mobile phone.
These devices will connect together to create a mesh network that relays messages, location and telemetry data. The LoRa protocol allows a low-power and long-distance communications, but if you don’t have any other node near you to connect with, you can always use a MQTT server, you can even host your own!
If you are looking to build a node or just want to find out more, search for Meshtastic groups in your area! In Italy we have this awesome community on Telegram that shares projects, ideas, knowledge and support.
You can learn a lot and find other people near you to connect with.
You should know that similar projects exist: take a look at the LoRa APRS or the MeshCore project.
How to start?
You can learn more about LoRa messaging by visiting my project’s website LoRa Brescia (italian).