Mavlink long-range telemetry radio over LTE Cat M1
A couple of months ago I made a long range telemetry radio using an old Dell DW5811e 3G/4G modem and a Pi Zero. This worked fine, until I somehow broke the antenna which killed the modem. The modem does react to commands, but signal strength stays at 0%.
Mor about that in this video: • ARWing Pro, the road to VTOL
Also, the combination Pi Zero + NGFF modem is quite bulky if one wants to fit it in smaller vehicles such as the ZOHD Drift, AtromRC Dolphin, or a 7" quadcopter.
During the search for a smaller solution I stumbled over the Nordic nRF9160. Only 10x16mm in size, microcontroller included. I could design a board with it that fits a 20x20mm flight stack, make it run with MSP and use it on my racing drones! Love at first sight, so I got myself a board with that thing on it.
So far it seems to work out pretty well. I am not a software engineer by trade, but I managed to whip up this initial working version quite quickly.
Next up is something like DTLS for added security, and of course actual in-the-air testing.