Design of a Low-Power Wireless Sensor Network for Environmental Monitoring in UNIZIK Campus

Environmental data collection for campus sustainability reporting at Nigerian universities remains largely manual and infrequent, limiting the accuracy and timeliness of ecological impact assessments. This study designs a low-power wireless sensor network (WSN) for continuous environmental monitoring across the Nnamdi Azikiwe University (UNIZIK) campus in Awka, measuring temperature, humidity, noise levels, and carbon dioxide concentrations. The network employs LoRa (Long Range) communication technology, with 12 sensor nodes distributed across the campus and data aggregated at a central LoRaWAN gateway connected to a cloud visualization platform. Sensor nodes were designed around the TTGO LoRa32 module with SHT31 temperature/humidity, MH-Z19 CO2, and MEMS microphone sensors. Node enclosures were designed for outdoor durability. The WSN was deployed for a four-week monitoring period, with data collection intervals set at 10 minutes per node. Results indicate that all 12 nodes maintained network connectivity throughout the monitoring period with an average packet delivery ratio of 96.4 percent. CO2 concentrations in lecture hall zones exceeded 1,000 ppm during peak occupancy periods, indicating ventilation improvement needs. Battery life per node averaged 21 days on a 3.7V 3400 mAh LiPo cell. The study concludes that LoRa-based WSNs offer a robust and energy-efficient monitoring solution for Nigerian university campuses. Recommendations include solar energy harvesting for node recharging and data integration with UNIZIK's sustainability reporting framework.