I got a chinese co2 sensor MH-Z19C
Hooked up to easpesy it reports being MH-Z19B
Is there any difference?
It appears that the measured values is not stable. All around 400PPM
After asking the supplier they advised to calibfrate the sensor with nect instructions.
Is that doable using the esp?
Thanks,
Bart
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Set a certain concentration calibration function:
For example: Current environmental concentration is 600ppm, send the following command via serial port;
FF 01 AD 02 58 00 00 00 F8 (this data is hexadecimal, i.e., 600ppm converted to hexadecimal is 02 58)
The sensor returns following command:
FF AD 01 00 00 00 00 00 52 means the sensor receives command correctly and then performs calibration. The sensor will be calibrated to the set concentration within a few minutes, usually there will be a +/-10ppm deviation;
The sensor returns following command:
FF AD 00 00 00 00 00 00 53 means the sensor has not received command correctly and cannot be calibrated.
When you send this command to the sensor, there must be 3 prerequisites:
1. The sensor has been powered on for more than 2 hours; 2. CO2 concentration of the sensor in current environment shoule be between 400 and 1000 ppm and cannot exceed this range, otherwise sending this command will be invalid.
3. CO2 concentration of the environment needs to stabilize for more than 10 minutes before sending this command, otherwise the calibration deviation will be relatively large.