“A couple of weeks ago, I read an article about CO2 levels and how they may indicate higher transmission of COVID-19 in an indoor space. After reading this article, I wanted to take a crack at designing a simple CO2 detector that could visually display carbon dioxide levels in the air.
The assembly consists of a neopixel ring to display different colors to indicate the CO2 levels. I will use an SCD-41 CO2 sensor to detect the CO2 levels. I have also included a couple of other sensors to display temperature, pressure, and humidity in later iterations. An RP2040 board is set up to read these sensors and control the neopixel ring.
The following steps will walk through the assembly and programming of the CO2 detector.
Here is a list of the required components for this CO2 detector build:
1 - Adafruit Feather RP2040
1 - Adafruit SCD-41 - True CO2 Temperature and Humidity Sensor - STEMMA QT / Qwiic
1 - Adafruit DPS310 Precision Barometric Pressure / Altitude Sensor - STEMMA QT / Qwiic
1 - Adafruit DS3231 Precision RTC - STEMMA QT
1 - CR1220 12mm Diameter - 3V Lithium Coin Cell Battery - CR1220
1 - Adafruit Prop-Maker FeatherWing
2 - STEMMA QT / Qwiic JST SH 4-pin Cable - 100mm Long
1 - STEMMA QT / Qwiic JST SH 4-pin Cable - 200mm Long
1 - Breadboard-friendly SPDT Slide Switch
1 - JST PH 2-Pin Cable - Female Connector 100mm
1 - JST PH 2-Pin Cable – Male Header 200mm
1 - NeoPixel Ring - 24 x 5050 RGB LED with Integrated Drivers
1 - JST PH 2mm 3-Pin Socket to Color Coded Cable - 200mm
1 - Lithium Ion Cylindrical Battery - 3.7v 2200mAh
4 - M3 x 12mm Machine Screws
4 - M3 Hex Bolts
4 - 2.5M x 10mm Metric Machine Screws
4 - 2.5M x 20mm Metric Machine Screws
8 - 2.5M Metric Hex Nuts
8 - #4-40 x 3/8 Machine Screws
4 - #4-40 Hex Nuts
4 - #4-40 Square Nuts
You will also need to 3D print the enclosure, frames, and lid for the CO2 detector.”