COSIO CO₂ Sensor IoT CO₂ sensor based on the ESP8266 and MH-Z19c NDIR CO₂ module. Needed software VS code or Atom with PlatformIO extension The official product site https://cosio.christmann.info/ Building guide https://www.instructables.com/COSIO-AIR-QUALITY-SENSOR-WITH-WIFI-MQTT/