CozIR®-A 10,000ppm CO2 + RH/T Sensor

Works well, but SIO comms can be frustrating

Implemented on Teensy 4.0 programmed with Arduino IDE. I gave this a four-star rating because I ran into unexpected serial IO communication issues that caused frustration trying to track it down. Specifically, on every power up I discovered that the first command sent to the my COZIR always returns a "?" indicating the command was unrecognized, even though it was valid. I resolved this by sending the same command twice. Additionally, when using poll mode I had to build in a 30-50ms delay between command send and data receive. This seems a little slow to me based upon other serial sensors I have used but not a big deal since I only read the sensor once per second. So just be careful of timing issues. Otherwise, quite happy with the sensor.

Affordable, easy to get set up

Bought this sensor as a way to monitor C02 in a greenhouse environment. Skipped their dev kit and opted for an ESP32 Devkit C. The ESP32 gives the sensor Wifi capability (and much more). I found the documentation provided for the sensor very complete, concise, and user friendly. Setting up the serial/UART and talking to the sensor was a breeze thanks to this. Plus it comes fitted with R/H and Temp. Very handy little sensor.