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

DESCRIPTION

The SGP40 Multi-Pixel Gas Sensor, is a fully integrated MOX gas sensor. This is a very fine air quality sensor from the sensor experts at Sensirion, with I2C interfacing so you don't have to manage the heater and analogue reading of a MOX sensor. It combines multiple metal-oxide sensing and heating elements on one chip to provide more detailed air quality signals. The SGP40 has a 'standard' hot-plate MOX sensor, as well as a small microcontroller that controls power to the plate, reads the analogue voltage and provides an I2C interface to read from. Unlike the CCS811, this sensor does not require I2C clock stretching.

This is a gas sensor that can detect a wide range of Volatile Organic Compounds (VOCs) and H2 and is intended for indoor air quality monitoring. The SGP40 is the next generation after the SGP30, but does not give TVOC/eCO2 values out like the SGP30. Instead, the raw signal from the sensor is processed using their software algorithm to give an overall 'air quality' value from 0 to 500.

Another nice element of this sensor is the ability to set humidity compensation for better accuracy. An external humidity sensor is required and then the RH% is written over I2C to the sensor, so it can better calibrate the MOX sensor reading and reduce humidity/temperature-based variations.

Along with being STEMMA QT and SparkFun Qwiic compatibility, they have also broken out all the pins to standard headers and added a 3.3V voltage regulator and level shifting so allow you to use it with either 3.3V or 5V systems such as the Arduino Uno, or Feather M4.

Please Note:

• This sensor, like all VOC/gas sensors, has variability, and to get precise measurements you will want to calibrate it against known sources!

RESOURCES

• Arduino Library