what is mh-z19 fr?

This project is a small piece of software that lets a Raspberry Pi talk to an MH-Z19 carbon dioxide sensor and report the current CO2 level in the air. It's built in the Go programming language and gives you a straightforward way to turn a cheap hobbyist sensor into a working air-quality monitor. The MH-Z19 is a common, inexpensive sensor that measures CO2 in parts per million. Normally, getting data out of it requires knowing the specific serial commands the sensor expects. This library handles that conversation for you. You connect the sensor to the Pi's serial pins, open that connection using a standard Go serial library, and call a single function to get a reading back as a number. Someone would use this if they're building a home air-quality station, a classroom CO2 monitor, or any DIY project that needs to know how stale the air is. A founder prototyping a smart-office product, or a hobbyist who wants a dashboard showing when to open a window, could use this as the data-gathering step. The example in the README just prints the number, but in practice you'd send that value to a dashboard, log it, or trigger an alert. The project is deliberately minimal. It doesn't include a web server, a database, or a fancy interface, it just gets the number off the sensor and hands it to you. That's a feature if you want to drop it into a larger system without dragging in extra dependencies, but it means you'll need to write the surrounding plumbing yourself.