VirtualWire Library, for very cheap wireless communication
Amazon.com: HiLetgo ESP32 SX1262 LoRa Kit 863-928MHz Bluetooth 4.2+WiFi+LoRa LoRaWAN Wireless Communication Development Board with 0.49" OLED Display 64M Bits Flash Works with Arduino IDE Type C : Electronics
Wireless Communication between Arduino & Raspberry Pi using LoRa Module SX1278
Arduino and HC-12 Long Range Wireless Communication Module - How To Mechatronics
Long Range, 1.8km, Arduino to Arduino Wireless Communication With the HC-12. : 6 Steps (with Pictures) - Instructables