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    BMP581 water level measurement

    BMP581 water level measurement

    New Poster


    I want to measure the water level with bmp581.

    So, how does this sensor track water levels with mm precision?

    Bosch Video (84) Detecting the water level of a washing machine powered by BMP390 - seems to be suggested by YouTube.

    Is there any example code or guide document I can refer to?

    8 REPLIES 8

    Community Moderator
    Community Moderator

    Hi PeterMark,

    For water level of a washing machine with mm precission, formula is " p=ρgh". we're supposed to substitute p as 50pa, ρ as 1000kg/m3, g as 9.8N/kg, and then we can get that h is equal to around 0.005m.

    Hi BSTRobin, thanks for your reply.
    I have a few more questions.

    1. Should I use only one sensor and apply it to the formula?
    2. Is there any problem setting the sensor as shown below?

    Pressure oversampling: x16
    Temperature oversampling: x2
    IIR filter coefficients: 4

    3. Should we consider a measuring device like the one below?




    Community Moderator
    Community Moderator

    Hi PeterMark,

    1, 3: In Youbute video, measuring device is like this, you need to use two sensor.

    water depth calculation.png
    2. Yes, you could use the sensor setting you mentioned. And you could also use other sensor setting, refer more BMP5 example code:

    Hi BSTRobin

    thanks for your reply.
    I have a few more questions.

    1. Why is 95817.06pa a reference?

    2. Is the position of P0 a pressure input in the drum? Is it the pressure around?
    3. Should I simply get the P-P0 pressure? Is there a calibration value?
    4. Does the size of the tank not matter?
    5. Is it possible to measure up to 1mm?