I think you should have a try to change your timestamp, currently I only suspect it.
Did you use mark pen or other gases to stimulate BME680 after power on 5 minutes?
Sorry it was my mistake. File bme_user_updated.c , which was in my initial post works. During testing I accidentaly changed Low Power Mode to Continous. Bluetooth stack is running in my apllication. I tried to turn the stack off. When Bluetooth was turn off IAQ metering worked even in Contious mode. Than I realized I set wrong metering mode and changed it to Low power mode. Now it works even with Bluetooth. Thank you for your support.
I have one more question.
I plan to use BME680 to meter/analyze CO2 and IAQ in flats and houses. Devices will be placed in one place for long periods(months or years). Which configuration/metering period would you recommend to achieve maximum accuracy? Is there a way to manualy (by code) start calibration when IAQ accuary level is not 3?
LP mode is ok and regarding 4d or28d configuration you should know the sensor placed where the airflow change speed is slow or fast.
Don't need a way to manualy (by code) start calibration when IAQ accuary level is not 3, only keep air quality changed and calibartion will be executed by BESC algorithm.
BME will be placed in one room of a house. Staticaly pluged in electrical socket. I can not guarantee change in air quality. Is there a way to start calibration by code or keep IAQ accuracy level at 3? I do not want to wait for air quality change and loose data.
For slow airflow change speed is recomended 4d or 28d configuration?
I am not sure that how long the accuracy reachs to 3 with slow airflow change speed.
BESC output is only a relative value, indicate the current environment become worse or better with the previous time, so it must know what is bad and good.
If you want to get accuracy 3, air quality change has to be meet.