This project utilizes a Raspberry Pi Pico and classic 0.96" OLED to read and display current CO2 levels. There are similar projects using Arduino or ESP32, but I have not seen someone using a Pico yet. Its cheaper, smaller, and less power hungry which is why it was chosen. I did not need wireless capabilities in my case, however using a Pico W you could easily impliment this.

Programmed in Micropython with ssd1306 library for the OLED.

Features include:

• Warm up time with progress bar
• PPM Display with bar graph
• Interpretation of PPM ranging from Mild to Hazard
• Software PPM calibration with instructions
• Line indicating level at which cognitive ability begins to become impared (according to 2016 Harvard study)

Harvard Study on Cognitive Functions at Different CO2 Levels

MH-Z19B Manual

Thingiverse link for case