3 ms·

You should be using the newer version, MH-Z19B, not MH-Z19. The protocol is compatible though. Also note they come in up-to-3000ppm and up-to-5000ppm variants

You should be using the newer version, MH-Z19B, not MH-Z19. The protocol is compatible though. Also note they come in up-to-3000ppm and up-to-5000ppm variants. Be sure to get the latter. In case it helps anyone: a very fast way to get it working and get graphs is to connect it to a Raspberry Pi running HomeAssistant. Takes a few clicks and 3 lines of config.

cosmic_shame 6y ago
For portability, you can also hook up to an ESP8266/ESP32 and configure to talk to HomeAssistant via ESPhome: https://esphome.io/components/sensor/mhz19.html https://esphome.io/components/sensor/mhz19.html