Adafruit SGP41 Multi-Pixel Gas Sensor Breakout - VOC & NOx - STEMMA QT / Qwiic

Do you smell that? Build a digital nose with the Adafruit SGP41 Multi-Pixel Gas Sensor, a fully integrated metal-oxide (MOX) gas sensor from Sensirion with I2C interface. This fine air quality sensor includes multiple metal-oxide sensing and heating elements on one chip to provide more detailed air quality signals. It adds a dedicated NOx sensing pixel alongside VOC detection.

The SGP41 features two MOX hot-plate sensor elements (VOC and NOx) and a microcontroller that manages power, analog reading, and I2C communication. It does not use I2C clock stretching, simplifying communication. Libraries for Arduino and Python/CircuitPython are available to read raw VOC and NOx signals, compatible with Raspberry Pi and CircuitPython boards.

This sensor detects a wide range of VOCs and oxidizing gases such as NOx, mainly intended for indoor air quality monitoring. The two raw signals processed by Sensirion's Gas Index Algorithm provide VOC and NOx Index values on a 1 to 500 scale, with 100 indicating a typical indoor environment.

Humidity and temperature compensation can be set for better accuracy, requiring an external sensor to write RH% and temperature over I2C.

The sensor is mounted on a custom PCB in the STEMMA QT form factor with STEMMA QT connectors compatible with SparkFun Qwiic connectors for easy solderless connections and chaining of devices. Pins are broken out to standard headers with a 3.3V regulator and level shifting for compatibility with 3.3V or 5V systems like Arduino Uno or Feather M4.

• Fully integrated MOX gas sensor with I2C interface
• Detects VOCs and NOx gases
• Two MOX hot-plate sensor elements plus microcontroller
• No I2C clock stretching required
• Humidity/temperature compensation supported
• STEMMA QT compatible for easy connection
• 3.3V regulator and level shifting onboard