Starting with the recommended schematic for the ESP32, the most obvious things to remove are a number of the interfacing components like the USB to UART chip and the JTAG interface. The ESP32 has ...

To simplify this, [Timm Bogner] created Farm Data Relay System which simplifies the ... The FDRS uses a combination of ESP32/8266 sensor nodes for short range, and LoRa nodes for long range.