Adafruit SGP40 AIR QUALITY SENSOR

The Adafruit SGP40 Air Quality Sensor Breakout is a next-generation indoor air quality sensor designed to measure VOCs and hydrogen gas. It uses a metal-oxide (MOX) sensing element combined with an on-chip microcontroller to manage the heater, read analog values, and provide a straightforward I2C interface. Unlike the CCS811, this sensor does not require I2C clock stretching.

The SGP40 outputs a raw signal that can be processed with Sensirion’s algorithm to calculate a VOC index from 0 to 500. It is ideal for monitoring air quality trends indoors, though for precise readings it should be calibrated against known sources. Additionally, the sensor supports humidity compensation: by feeding it relative humidity values from an external sensor via I2C, the device can adjust its readings to reduce errors caused by environmental variations.

Adafruit’s breakout board makes integration easy. The SGP40 is mounted on a custom STEMMA QT PCB with a built-in 3.3V regulator and I2C level shifting, so it works with both 3.3V and 5V systems. STEMMA QT / Qwiic connectors on both sides allow for solderless connections and daisy chaining with other I2C devices. All pins are also broken out to a standard header for breadboard use. Please note: QT cable not included.

Features:

• VOC and H₂ detection for indoor air quality monitoring
• MOX sensor with integrated microcontroller
• I2C interface (no clock stretching required)
• VOC index output (0–500) via Sensirion software algorithm
• Humidity compensation support with external RH sensor input
• Compatible with both 3.3V and 5V systems
• Arduino library available

Package Includes:

• 1 × Adafruit SGP40 Air Quality Sensor Breakout

Links:

• Product page