Hi there,

for monitoring air pressure, temperature and (relative) air humidity, I
purchased a few "breakout boards" carrying Bosch BME280 sensor.

There are several models out there with different board layout, most of
them from China.

So, to monitor those envirmonment values I have several Raspberries where
each one is connected to a BME280 via I2C. Same worked with Arduino
formerly, but I want them to be connected via internet / wifi.

Nothing special. Yes?

Well, what I am wondering about is, that temp. and pressure are very
similar on every board, but not so the relative humidity.

Most significant "outlayer" is produced by Adafruit BME280, which claims
that the humidity value is around 10 percent points higher than most
other sensors (i.e., 40% China noname and 50% Adafruit). There was no
difference whether connected one after the other, or both, Adafruit and
China noname on the same bus with different addresses.

I think, assuming that Adafruit's values are the most precise ones, just
because this is the most expensive one, is a little too naive :-)

Any experiences with that stuff, or knowing ways to test / verify /
calibrate those modules?

Best regards,

Markus


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