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    Are there a default, identity values for the calibration data of the BME280

    Are there a default, identity values for the calibration data of the BME280

    New Poster

    Hi there,


    I am in the process of creating a software version of the BME280 and one thing I cannot find is how to 
    program the calibration data such that I can simply use raw values that would be equal to the compensated values

    For example if I have a raw temperature (16.4 format) with the value 0x3FFF0 then have a value that reads something like 84.99 celsius 

    Alternatively, is there a way to invert the formulas such that if I start with a temperature I can compute the raw value? 

    11 REPLIES 11

    Community Moderator
    Community Moderator

    Hi bonnyr,

    Please refer "chapter 4.2 Output Compensation" in BME280 data sheet.

    BME280 compensation formulas.png

    Hi BSTRobin,

    I think I did not make myself clear on what I am trying to do - I am trying to produce values that a typical sensor would in software.
    In other words, I am simulating the sensor.

    So I need to find out how to compose the raw values, so that when some code (running on arduino) reads temperature for example, and they
    use the Bosch libraries you're citing, they will get reasonable values from the raw values the simulation generates.

    I tried to understand what each of the coefficients does so that I can compute the raw values (t,p,h) from measurements, (for example what 
    raw value I should have for a temperature of 25 deg c) but failed 🙂 

    So, I am asking for a way for me to simply, map the range of temperatures to an ADC values (for temp, use 20bits for the ~125 deg possible) and
    have a default coefficient map that would be like an identity operation map ( multiply or divide by 1, add or subtract 0, etc)

    I hope this is possible

    @BSTRobin  - I'm wondering whether what I'm after is possible?





    Community Moderator
    Community Moderator

    Hi bonnyr,

    The calibration parameters of the BME280 are hardware related and not used to simulate sensor data. If you want to simulate a sensor, this method does not apply to you.
    The software simulates the sensor, which needs your own calculation.