Problem Statement

Toxic winter air pollution inversions, summer wildfire smoke plumes, and severe alpine weather fronts do not recognize national borders across the Balkan peninsula. At the same time, high border ridges (Šar Mountain, Korab, Belasica, Osogovo) offer exceptional Line-of-Sight spanning 80 to over 140 km across frontiers. Yet, state environmental monitoring remains fractured across slow bureaucratic silos, while commercial data transmission is crippled by expensive cellular roaming. This sprout builds an autonomous, open-hardware cross-border sensor mesh operating on the license-free 868 MHz LoRa/Meshtastic spectrum to relay vital environmental telemetry freely across borders.

Open Hardware Bill of Materials (BOM Hints)

  • Radio Node & Repeater: Semtech SX1262 LoRa transceiver on 868 MHz (+22 dBm PA output) mated with a 5.8 dBi omnidirectional fiberglass collinear antenna; ultra-low-power RAK Wireless WisBlock (Nordic nRF52840) or Heltec Wireless Tracker core.
  • Power Subsystem for Sub-Zero Extremes: 30W glass-laminated monocrystalline solar panel; 12.8V 15Ah LiFePO4 battery pack equipped with an active BMS featuring a hardware-enforced 0°C low-temperature charge cutoff and a self-heating silicone pad powered strictly by excess solar input down to -25°C.
  • Ruggedized Enclosure: UV-resistant IP67 polycarbonate enclosure fitted with a Gore-Tex hydrophobic membrane vent for internal pressure equalization without condensation buildup; stainless steel mast mounting hardware.
  • Sensor Instrumentation Suite: Sensirion SPS30 laser optical particulate matter sensor (PM1.0, PM2.5, PM4, PM10); Bosch BME280 (temperature, relative humidity, pressure); Figaro TGS2600 / Sensirion SGP41 sensor for early wildfire smoke, CO, and volatile organic compounds.

Schematics & Experiment Notes

  1. Mountain Line-of-Sight Radio Propagation: Stationed at 1800m to 2200m ASL, repeaters command optical Line-of-Sight into neighboring valleys in Kosovo, Serbia, Bulgaria, and Greece. Configured with Spreading Factor 11 (SF11) and 125 kHz bandwidth, the link budget achieves 148 dB, enabling reliable packet exchange beyond 100 km without cellular towers.
  2. Early Wildfire Detection Heuristic: Firmware evaluates a dynamic combustion anomaly score ($S_{\text{fire}} = k_1 \frac{d(\text{PM2.5})}{dt} + k_2 \frac{d(\text{VOC})}{dt} - k_3 \cdot RH$). A sudden rise in particulate density and reducing gases accompanied by low humidity immediately shifts the node into alarm mode, flooding high-priority LoRa alert packets across the regional mesh.
  3. Zero Cellular Roaming Expense: Packets travel peer-to-peer over license-free ISM spectrum, bypassing cellular telecom providers, foreign roaming fees, and centralized infrastructure completely.

Call for Contribution (How to Join)

  • Mountaineers & Hikers: Help carry and deploy solar repeater pods at alpine huts, mountain shelters, and summits along international border ridges.
  • Developers & Web Analysts: Join the development of an open regional web dashboard visualizing real-time transboundary air quality and wildfire hazard telemetry.
  • Firmware Optimizers: Assist in tuning solar power management and packet collision mitigation algorithms during multi-week winter blizzards.