Breathe easy - we finally have an I2C VOC/eCO2 sensor in the Adafruit shop! Add air quality monitoring to your project and with an Adafruit CCS811 Air Quality Sensor Breakout. This sensor from AMS is a gas sensor that can detect a wide range of Volatile Organic Compounds (VOCs) and is intended for indoor air quality monitoring. When connected to your microcontroller (running our library code) it will return a Total Volatile Organic Compound (TVOC) reading and an equivalent carbon dioxide reading (eCO2) over I2C.
The CCS811 has a 'standard' hot-plate MOX sensor, as well as a small microcontroller that controls power to the plate, reads the analog voltage, and provides an I2C interface to read from.
This part will measure eCO2 (equivalent calculated carbon-dioxide) concentration within a range of 400 to 8192 parts per million (ppm), and TVOC (Total Volatile Organic Compound) concentration within a range of 0 to 1187 parts per billion (ppb). According to the fact sheet it can detect Alcohols, Aldehydes, Ketones, Organic Acids, Amines, Aliphatic and Aromatic Hydrocarbons.
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! That said, for general environmental sensors, it will give you a good idea of trends and comparisons.
The CCS811 has a configurable interrupt pin that can fire when a conversion is ready and/or when a reading crosses a user-settable threshold. The CCS811 supports multiple drive modes to take a measurement every 1 second, every 10 seconds, every 60 seconds, or every 250 milliseconds.
For your convenience we've pick-and-placed the sensor on a PCB with a 3.3V regulator and some level shifting so it can be easily used with your favorite 3.3V or 5V microcontroller.
We've also prepared software libraries to get you up and running in Arduino or CircuitPython with just a few lines of code!
The breakout is made in the STEMMA QT form factor, making them easy to interface with. The STEMMA QT connectors on either side are compatible with the SparkFun Qwiic I2C connectors. This allows you to make solderless connections between your development board and the BME280 or to chain it with a wide range of other sensors and accessories using a compatible cable.