Affordable and reliable cell phones have revolutionized the way we communicate over the last two decades or so, and this change has been accelerated only by the adoption of smartphones. This is all well and good if you live in a place with cellular infrastructure, but if you live in a more remote area you need to be a little more innovative. This text-based communication device, for example, lets you send text messages without that cumbersome infrastructure.
When [Arthur] This project is not specifically designed for off-grid use, yet it is an interesting project. The devices use a physical QWERTY keyboard and a smaller screen, reminiscent of BlackBerry devices of the late 2000s (partly because they were actually using a BlackBerry keyboard). One of the other goals of this project was low power consumption, and in receiving and sending messages using keyboard, memory LCD, and LoRa, [Arthur] Was able to bring the current draw down to 12 mA.
Among the relatively common nRF52840 and SX1262 chips, it is also true that [Arthur] Schematics has been made available, making it an excellent off-grid device for anyone who likes to drive in the desert or live far enough out of town that the cell phone reception is a concern.
Looking for something a little easier to put together before your upcoming camping trip? It is similarly styled LoRa Communicator [MSG] Uses off-the-shelf modules to greatly reduce portion counts. Another option for off-grid communication is to use existing smartphones connected to the LoRa network that we saw in this project.