Carbon dioxide, aka CO2, is a gas that is an essential part of the Earth's atmosphere and life in general. However, while essential, it can have negative effects when concentrations exceed certain level. It can impact the entire planet via global warming. But it can also have very local effects, for example on indoor air quality. Elevated levels of CO2 can lead to reduced cognitive ability and other health related concerns. Therefore, monitoring CO2 levels of inside air can be useful as a part of gauging general air quality.
Numerous projects have already been done to monitor indoor CO2. This project posted to Hackster uses an ESP8266 and a CCS811 to send values to Adafruit IO. This tweet (and also blog post with more info) shares a project done by an 11 year old and is based on the Feather ecosystem using the SCD-30 CO2 sensor from Sensirion. This is an excellent true CO2 concentration sensor which we also use in this project.
In this project we use the SCD-30 along with a Matrix Portal to drive a 64x32 RGB LED matrix. This provides a nice way to display the current conditions and have it be readable to an entire room. And as a bonus, with this hardware arrangement, there is no soldering required!
Here's a summary of the hardware needed for this project. Some items are optional. Also note that if you purchased an Adabox 016, you will have most of these items already.
The key item is of course the SCD-30 CO2 sensor itself:
To provide a solderless way to connect the SCD-30 to the Matrix Portal, you can use a STEMMA QT cable. They come in various lengths:
You'll also need a 64x32 LED matrix and a Matrix Portal to drive the matrix:
OPTIONAL. You can add one of these acrylic diffusers to provide a more matted look to the display: