A Simulated IoT Embedded System for Classroom Indoor Air Quality, Noise, and Lighting Monitoring: Architecture and Firmware Performance Analysis

Indoor environmental quality in university classrooms significantly influences the overall 11 well-being of occupants. However, implementing continuous monitoring networks is of-12 ten restricted by high equipment costs. This paper presents the architectural design, firm-13 ware implementation, and virtual validation of a low-cost, multi-sensor IoT system aimed 14 at monitoring key environmental parameters: air quality index indicators, ambient light, 15 and acoustic distress indicators. The system architecture centers on an ESP32 microcon-16 troller, integrated with simulated response curves for an MQ-135 sensor, an LDR, and a 17 sound detection module. Due to physical deployment constraints, the system was strictly 18 validated using electronic simulation software (Proteus VSM). The simulation results 19 demonstrate a reliable firmware execution with an algorithm latency under 10 ms during 20 multi-trigger alarm states. Furthermore, a virtual power consumption analysis was con-21 ducted, revealing an average current draw of 100 mA under normal operations and a peak 22 dynamic current draw spanning from 130 mA up to 280 mA during high-priority alarm 23 cycles. The proposed virtual framework establishes a technically viable, open-source blue-24 print for rapid-deployment environmental telemetry before transitioning to physical scal-25 ing.