AirGradient ONE

airgradient · I-9PSL

The AirGradient ONE is an indoor air quality monitor designed to accurately show whether the air in a home, office, classroom, or enclosed space is healthy. The I-9PSL model measures PM2.5, CO2, TVOC, NOx, temperature, and humidity, displaying the information both on its built-in OLED screen and through a configurable RGB LED bar. Unlike many closed commercial sensors, the AirGradient ONE is open-source and open-hardware, which means you can modify the firmware, adapt the device, inspect the schematics, or send data to your own platforms. It can also be used with the AirGradient dashboard, with Homey, or directly with Home Assistant. Since Home Assistant 2024.6, and with updated firmware, AirGradient reports native support with local autodetection. This makes it an especially appealing option for home automation users who want to track CO2, particles, and volatile organic compounds in Home Assistant without having to rely on a closed cloud. The monitor uses an ESP32-C3-MINI with 2.4 GHz WiFi and Bluetooth LE. For CO2, it uses SenseAir S8 or S88 NDIR sensors; for particles, it uses the Plantower PMS5003; for TVOC and NOx, it uses the Sensirion SGP41; and for temperature and humidity, it uses the Sensirion SHT40. The assembled version includes chamber testing, a test report, certifications, and warranty, while the kit version uses the same hardware but requires assembly by the user.