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WifWaf / MH-Z19

For Arduino Boards (&ESP32). Additional Examples/Commands., Hardware/Software Serial
GNU Lesser General Public License v3.0
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get background CO2 #34

Closed wasteoinc closed 3 years ago

wasteoinc commented 3 years ago

Now that I finally experiment I have another question.

I did a manual calibration as you suggested in your examples. I left the device outside for 20-30 minutes and then I pulled the DH pin to ground for 7 seconds. The readings calibrated to 400 and then i let it run for another 10 minutes to see if it's stays there.

After that i placed the device inside a closed room to show the higher readings. It did willfully. But then i checked the getBackgroundCO2 commend and I noticed the following.

The getBackgroundCO2 was always printing the same as the CO2 command

Background CO2: 3067 ABC Status: OFF CO2 (ppm): 3067 Temperature (C): 20

Background CO2: 3100 ABC Status: OFF CO2 (ppm): 3100 Temperature (C): 20

If I got the documentation correctly the getBackgroundCO2 should have been a constant 400 after the calibration. Have you any idea what am i missing?

WifWaf commented 3 years ago

This is not your error, nor the senors.

Newer firmware versions (which are hard to keep track of) have replaced the registry entry with the last CO2 reading taken (or so it appears).

I have an idea of how to request the data from all versions, but until then, I plan to remove the function from the working examples.

Hopefully, this helps?

wasteoinc commented 3 years ago

of course it does, thanks