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    BME688 power modes

    ramsie
    New Poster

    BME688 power modes

    My problem is that I don't know at what point the gas value provided by the sensor is accurate. Do I have to wait until the response time (i.e. low power mode: 1,4 seconds) expires before the value is accurate or not?

    The BME688 datasheet describes different energy saving modes.

    Gas sensor parameter specification:

    Ultra-low power mode (response time 92 seconds)
    Low power mode (response time 1.4 seconds)
    continuous mode (response time 0,75 seconds)

    I program the BME688 with the Arduino IDE (development environment).

    I used the example code, provided under the following link:

    https://github.com/BoschSensortec/BSEC-Arduino-library/blob/7a9357566c75048331c15b55a4eb20f1de14f36e...

    In line 36 the following command is executed: iaqSensor.updateSubscription(sensorList, 10, BSEC_SAMPLE_RATE_LP);

    I think this is where the power saving mode "low power" is executed.

    I get values for gas concentration every time the loop executes the corresponding command.

    What if I only request the value once. I then shut down the microcontroller and the BME688 for 10.8 seconds. If I repeat this procedure a total of 5 times, does this correspond to the standard gas scan mode?

    Basically, I don't understand the energy saving modes. It is unclear to me if there is an internal delay to ensure that the response times are met.
    Under duty cycle of standard gas scanner mode it is described that tstandard scan takes 54 seconds and tstandard sleep takes 108 seconds. What does all this mean? How can I understand the duty cycle?

     

    1 REPLY 1
    BSTRobin
    Community Moderator

    Re: BME688 power modes

    Hello ramsie,

    When the IAQ accuracy value is 3, you can think that the data is credible.
    Yes, the line "iaqSensor.updateSubscription(sensorList, 10, BSEC_SAMPLE_RATE_LP)" performs the configuration of low power consumption.
    In this case "Under duty cycle of standard gas scanner mode it is described that tstandard scan takes 54 seconds and tstandard sleep takes 108 seconds.", duty cycle is 1:2.

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