Adafruit SGP40 Air Quality Sensor Breakout - VOC Index - STEMMA QT / Qwiic [PID:3709] - (AD46492)

Description:

*sniff* *sniff*... do you smell that? No need to stick your nose in a milk carton anymore, you can build a digital nose with the SGP40 Multi-Pixel Gas Sensor, a fully integrated MOX gas sensor. This is a very slim air quality sensor from the sensor experts at Sensirion, with an I2C interface so you don’t have to manage the heater and analog readout 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 board, reads the analog voltage, and provides an I2C interface for reading. Unlike the CCS811, this sensor does not require extending the I2C clock. We currently have an Arduino library with examples of reading the raw value and also running the Sensirion algorithm for calculating the VOC index, and a Python/CircuitPython library that can be used with Linux computers like the Raspberry Pi or our CircuitPython boards.

This is a gas sensor that can detect a wide range of volatile organic compounds (VOCs) and H2 and is designed to monitor indoor air quality. The SGP40 is the next generation after the SGP30, but it doesn't provide TVOC/eCO2 values like the SGP30. Instead, the raw signal from the sensor is processed using its software algorithm to give an overall "air quality" score from 0 to 500.

Keep in mind that this sensor, like all VOC/gas sensors, has variability, and for accurate measurements, you'll want to calibrate it with known sources. That said, for general environmental sensors, it will give you a good idea of trends and comparability.

Another great feature of this sensor is the ability to configure humidity compensation for greater accuracy. An external humidity sensor is required, and the %RH is then written to the sensor via I2C, allowing you to better calibrate the MOX sensor reading and reduce humidity/temperature-based variations.

Good sensor, right? So we've made it easy for you to jump right into your next project. The surface-mount sensor is soldered onto a custom-made PCB in the STEMMA QT form factor, making it easy to interface. The STEMMA QT connectors on both sides are compatible with SparkFun Qwiic I2C connectors. This allows you to make solderless connections between your development board and the SGP40 or link it with a wide range of other sensors and accessories using a compatible cable. The QT cable is not included, but we have a variety in the store.

Of course, we've broken out all the pins to standard headers and added a 3.3V voltage regulator and level shifting so you can use it with 3.3V or 5V systems, like the Arduino Uno or Feather M4.

Reference link