LoRa, the Long Range wireless protocol is pretty great for trickling data across long distances. There are some great embedded devices based around STM32, NRF52, and ESP32 microcontrollers.
On the hardware side, [Dan] has been using the STM32 NUCLEO-144 development boards with F4/L4/F7/H7 microcontrollers and a custom shield with a 1 W LoRa module and OLED screen. While [Dan] wants ...