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    BME280 pressure reads always high

    BME280 pressure reads always high

    PigsInSpace
    New Poster

    I have written a python driver interfacing to the BME280 via the bus pirate logic analyser. Temp and humidity values appear "believable" (they may be off a bit but we're talking a few percentage points at most). Pressure values, however, are much too high - I am reading north of 151229 Pa. Three different BME280 sensors on 3 different boards all read and behave the same with T and HR fine/in range and P reading much too high. I've used the Bosch spreadsheet to verify the compensation method and when i feed in the value I am reading from the bulk measurement as well as the calibration factors, the spreadsheet agrees with my own computed value. Yet, 150K Pa is much too high. It seems the raw pressure value is off but that is hard to explain if all 3 sensors are off similarly.

    p1 0x9373
    p2 0x-2997
    p3 0xbd0
    p4 0x20c2
    p5 0x-18
    p6 0x-7
    p7 0x26ac
    p8 0x-27f6
    p9 0x10bd
    Raw pressure: 0x170

    2 REPLIES 2

    PigsInSpace
    New Poster

    Realized reporting the values in hex is confusing and omitted the t fine value, here is that data again:

    p1 37747
    p2 -10647
    p3 3024
    p4 8386
    p5 -24
    p6 -7
    p7 9900
    p8 -10230
    p9 4285
    Raw pressure: 496
    T fine: 128017.03

    BSTRobin
    Community Moderator
    Community Moderator

    Hi PigsInSpace,

    Thank for your inquiry.
    You can refer to BME280 sensor API(https://github.com/boschsensortec/BME280_SensorAPI) and see what is the difference between your code and sensor API.

    2024-08-12_17h58_11.png

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