Quantity   Component name
3 × DFRobot FireBeetle ESP32
3 × E22-900M30S Ebyte LoRa Radio Modules
3 × 47µF Capacitors Filtering capacitors for radio modules.
3 × Toggle Switches For turning the power on or off
3 × 3.7V 2500mAh Lithium Ion Batteries Any capacity is fine; I think the more the merrier
3 × DC - DC 5V Boosters For stepping up the 3.7V battery to 5V
3 × 915mHz Omnidirectional Antennas I used 2dBi antennas, although 4 - 5dBi is optimal
2 × DFRobot BMI160
2 × DFRobot GPS Modules