Project Scentinel

THE CONCEPT Standard automated air fresheners operate on "dumb" timers, blindly spraying regardless of actual room conditions. The goal of The Scentinel was to retrofit a commercial shell into a context-aware IoT node that actively monitors air quality (temperature, humidity, and VOCs) and neutralizes odors only when thresholds are breached. ACADEMIC RECOGNITION This build was recognized by professors and supervisors at Linnaeus University (Applied IoT, 1DT305) and awarded 2nd Place out of a cohort of 62 total engineering submissions. SYSTEM ARCHITECTURE - The Node (Hardware): Programmed in MicroPython, a Raspberry Pi Pico W reads telemetry from a BME680 sensor. When triggered, it drives a DC motor via a DRV8833 driver while providing status feedback via an RGB LED and audio amplifier. - The Server (Software): Telemetry is published over Wi-Fi via the MQTT protocol to a local Mosquitto broker. The data is aggregated and visualized on a custom Home Assistant OS dashboard. CHALLENGES & BATTLE SCARS - PWM Conflicts: Debugged severe hardware timer conflicts where the audio output and RGB LED interfered with each other due to shared underlying PWM channels. - Server Incompatibility: Overcame a 32-bit UEFI bootloader restriction on the PC stick to successfully install the 64-bit Home Assistant OS. FUTURE ITERATIONS The ultimate goal is to evolve the project from simply masking air quality to actively solving it. Future versions will transition from automated deodorizing sprays to actuating window vents or controlling HVAC systems for true air exchange.