BME680 CO2 in ULP not changing

[goof]

Hi there,

Perhaps this is a trivial question and I am just being impatient with getting data but hopefully someone can clarify.

The bottom line is that when I start the sensor the reading for CO2 en TVOC keep at 500 and 0 respecitevely (if I do not initialize the state). 

Settings:  

• bsec_config_iaq -> generic_33v_300s_28d

• sensorList({

        BSEC_OUTPUT_RAW_GAS,

        BSEC_OUTPUT_CO2_EQUIVALENT,

        BSEC_OUTPUT_BREATH_VOC_EQUIVALENT        

    })

• I am ussing a Feather M0

The sequence of the program is as follows: 

Initialization:

• iaqSensor.begin(BME680_I2C_ADDR_SECONDARY, Wire);
• iaqSensor.setConfig(bsec_config_iaq);
• iaqSensor.updateSubscription(sensorList, 3, BSEC_SAMPLE_RATE_ULP);

Loop:

• iaqSensor.run(getTimeStamp()) (this returns the time in millis of an external real time clock)
• if run returns true do read: 
  • iaqSensor.co2Equivalent;
  • iaqSensor.breathVocEquivalent;
• When read done: device goes to sleep for 5 minutes (more precisely the interval is 5 minutes + 6 seconds
• Wake up (go back to top of loop)

This keeps giving the initial values of 500 and 0 for co2Equivalent and breathVocEquivalent

When I add upon initialization the setState step:  iaqSensor.setState(state); then I get a Co2 value of 562 all the time which is probably the value I stored previously but this does not change. 

question 1: when will the sensor (or bsec library) start to actually return out Co2 values?

question 2: how important is it to store the state and set it when the sensor is woken up? 

question 3: how long is that state valid?

question 4: would it be matter to let the sensor run outside on a normal power mode for let's say 15 minutes or so? or does it not matter at all?

Many thanks for the help!

Goof

[Jet]

Hi Goof:

     You are a nice guy, very appreciate you to share your experience.