Adafruit SGP40 Air Quality Sensor Breakout - VOC Index - STEMMA QT / Qwiic

The Adafruit SGP40 Air Quality Sensor is a fully integrated MOX gas sensor designed for indoor air quality monitoring. It detects a wide range of Volatile Organic Compounds (VOCs) and hydrogen using a multi-pixel gas sensor from Sensirion. This sensor features I2C interfacing, eliminating the need to manage the heater and analog reading manually.

The SGP40 sensor combines multiple metal-oxide sensing and heating elements on a single chip along with a microcontroller that controls power and processes sensor readings. Unlike other sensors, it does not use I2C clock stretching and outputs an overall air quality value from 0 to 500 using Sensirion's software algorithm.

Key Features:

• Fully integrated MOX gas sensor for VOC detection
• I2C interface for easy connection
• STEMMA QT / Qwiic compatible connectors
• Humidity compensation support via external sensor
• 3.3V regulator and level shifting for compatibility with 3.3V and 5V systems
• Compact breakout board with standard headers and mounting holes

This sensor is ideal for general environmental sensing and trend monitoring, though for precise measurements calibration against known sources is recommended. It is compatible with Arduino, CircuitPython, Raspberry Pi, and other microcontroller platforms.

The sensor is mounted on a custom PCB in the STEMMA QT form factor to allow solderless connections and easy chaining with other accessories. Please note that the supplied sensor may have variations in silkscreen design due to a recent PCB update.

Technical Details and Resources:

• Supports VOC index from 0 to 500
• Humidity compensation requires external humidity sensor
• Arduino and CircuitPython libraries available
• Compatible with STEMMA QT and SparkFun Qwiic connectors
• PCB revision updated Sep 18, 2023 with improved silkscreen

For more information, example code, and tutorials, please visit the Adafruit SGP40 Guide.