HewaSense: Advanced Indoor Air Quality & Safety Monitoring Platform

HewaSense is an advanced next-generation Indoor Air Quality Monitoring (AQM) platform developed as a major evolution of the OpenHAP environmental monitoring ecosystem. The system was redesigned from the ground up to provide broader environmental sensing coverage, ultra-low-power operation, and an improved industrial design centered around a low-power Electronic Paper Display (EPD). Designed for homes, offices, laboratories, healthcare environments, and commercial indoor spaces, HewaSense continuously monitors critical air quality and safety parameters to help maintain safe and healthy indoor environments.

Building on the original OpenHAP architecture, HewaSense integrates additional environmental sensing capabilities through the SPEC Sensors 97x-series gas sensors. The platform monitors Ozone (O₃) using the 97x-400 sensor, General Indoor Air Quality (IAQ) using the 97x-800 sensor, and Respiratory Irritants (RESP) using the 97x-900 sensor. These are combined with the original OpenHAP sensing stack consisting of Carbon Monoxide (CO), Particulate Matter (PM2.5), and Temperature & Humidity measurements from both onboard SHT30 sensors and distributed BLE environmental sensors. The result is a complete multi-parameter indoor safety monitoring platform capable of detecting both immediate and long-term environmental risks.

The hardware platform was redesigned around a modular dual-board architecture consisting of a primary processing and connectivity board together with a dedicated sensing and analog acquisition board. The system integrates precision analog signal conditioning, wireless communication interfaces, power management circuitry, and an ultra-low-power EPD interface for persistent display visibility with minimal energy consumption. The EPD technology enables critical environmental data to remain visible even when the system enters low-power states, significantly improving battery efficiency and deployment flexibility.

HewaSense leverages an ESP32-based embedded firmware architecture optimized for deterministic sensing, low-power operation, and resilient edge-to-cloud telemetry. The system supports Wi-Fi, BLE, and GSM-based connectivity for remote monitoring and distributed sensing applications. Environmental telemetry is processed locally and streamed to cloud infrastructure for visualization, analytics, and alerting, while the local EPD interface provides immediate user feedback directly on-device. The project focused heavily on measurement accuracy, signal integrity, environmental reliability, low-power embedded design, and long-term operational stability in real-world deployment conditions.