Carbon Monoxide Sensor Dataset from Real‑World Indoor & Outdoor Environments

This dataset contains carbon monoxide (CO) sensor measurements collected using an ESP32 microcontroller paired with an MQ‑7 gas sensor across multiple real‑world environments, including indoor spaces, outdoor open areas, and generator exhaust conditions. Each instance represents a time‑stamped sensor reading with environmental metadata (temperature, humidity, pressure), sensor electrical characteristics (ADC value, voltage, Rs, R0), contextual information (location, distance to source, ventilation), and estimated CO concentration in ppm. The dataset is suitable for research in environmental monitoring, embedded systems, sensor calibration, and machine‑learning tasks such as regression, anomaly detection, and hazardous‑level classification. Supplementary materials include hardware schematics and documentation to support reproducibility.