When traveling into the wilderness with a group of people, it’s good to have a method of communications set up both for safety and practicality. In the past people often relied on radios like FRS, CB, or ham bands if they had licenses, but nowadays almost everyone has a built-in communications device in their pocket that’s ready to use. Rather than have all of his friends grab a CB to put in their vehicle for their adventures together, [Keegan] built an off-grid network which allows any Android phone to communicate with text even if a cell network isn’t available.
The communications system is built on the LoRa communications standard for increased range over other methods like WiFi using a SX1278 chip and an ESP8266. The hardware claims a 10 km radius using this method which is more than enough for [Keegan]’s needs. Actually connecting to the network is only half of the solution though; the devices will still need a method of communication. For that, a custom Android app was created which allows up to 8 devices to connect to the network and exchange text messages with each other similar to a group text message.
For off-grid adventures a solution like this is an elegant solution to a communications problem. It uses mostly existing hardware since everyone carries their own phones already, plus the LoRa standard means that even the ESP8266 base station and transmitter are using only a tiny bit of what is likely battery power. If you’re new to this wireless communications method, we recently featured a LoRa tutorial as well.