“ABOUT COSIO
This guide will teach you how to build your own CO sensor for air quality monitoring. The sensor indicates bad air quality and shows when ventialtion is recommended, thus lowering the risk of infections carried by aerosols (like COVID-19). Elevated CO concentrations (> 1500 ppm) also have a negative impact on concentration and can cause sleepiness and other unwanted effects.
This sensor is monitoring the current CO concentration in ppm (particles per million) and indicates the level with RGB LEDs and an 0,96” OLED display in the front. The inbuild web interface allows remote CO monitoring over the network and provides a configuration interface for the sensor. The sensor has a measuring range of 0 - 5000 ppm and a tolerance of 50 ppm, which is sufficient enough for indicating bad air quality.
Check out the project’s website: https://cosio.christmann.info/ (In German)
Supplies:
Electronics and Components:
1x Winsen MH-Z19c NDIR CO₂ sensor module (with socket and cable [not pin header version])
1x Wemos D1 mini (ESP8266)
1x 0,96” Arduino OLED Display SSD1306 128x64 I2C/IIC
13x WS2812b on a 144/m stripe
1x 3D Printer & printed case components (case_complete.stl)
4x M2x5 Screws (most screw types work here. I used )
Tools:
Glue (superglue recommended)
Small flathead screwdriver
Exacto or cutter knife
Soldering iron and solder
Side cutter
Wire stripper
Software:
Slicer for the 3D Printer
Flashing method for Wemos D1 mini (select one)
If you want to tinker with the project’s code we recommend VS code with PlatformioIDE
If you want to install the ready-to-use software, install ESPEasyFlasher and download the provided binary file”