Carbon Dioxide Sensor MH-Z19b
The carbon dioxide sensor module MH-Z19b is a cheap and very simple sensor with the UART interface allowing concentration measurement in the range up to 5000ppm.
This project is a prototype device using this sensor and built with ESP8266 module.
The hardware design was made with Eagle CAD and available in the directory
The firmware for the device is written using PlatformIO and Arduino platform.