The Adafruit PMSA003I Air Quality Breakout is a compact laser-scattering particulate matter sensor with an I2C interface — a significant advantage over the UART-based sensors that dominate this category. Simply connect via STEMMA QT / Qwiic and start reading air quality data with no soldering required.

The sensor uses a laser to illuminate suspended particles in the air, then analyses the scattered light to calculate particle concentrations and size distributions. Data updates once per second over I2C, providing comprehensive readings across multiple particle size categories.

Key Features

• I2C Interface – Plug-and-play with any I2C-capable microcontroller or single-board computer; no UART or software serial needed
• STEMMA QT / Qwiic Connectors – Two JST SH connectors for solder-free daisy-chaining with other I2C devices
• Laser Scattering Sensor – Measures PM1.0, PM2.5, and PM10.0 concentrations in both standard and environmental units
• Particle Size Bins – Counts particles per 0.1 L of air in 6 size categories: 0.3 µm, 0.5 µm, 1.0 µm, 2.5 µm, 5.0 µm, and 10 µm
• 5V Boost Circuit – On-board voltage boost lets you power the sensor from either 3.3V or 5V
• 1-Second Update Rate – Fresh air quality data every second with built-in checksum verification

Ideal For

• Indoor and outdoor air quality monitoring stations
• Environmental data logging and research
• Smart home air quality dashboards
• Bushfire smoke and pollution detection

Package Contents

• 1× Adafruit PMSA003I Air Quality Breakout (fully assembled with STEMMA QT connectors)
• 1× Header strip (for optional breadboard use)

Resources

• Adafruit PM25 AQI Arduino Library
• Adafruit PM25 CircuitPython/Python Library
• Introduction to STEMMA QT