How to calibrate BMP280 temp sensor?

Hello all,

I’ll start my post off with wishing you the best for 2022 :slight_smile:

So, I had a question related to calibrating a digital temperature sensor!

It’s a Bosh BMP280 Digital Pressure Sensor

Which is on the NCD Connect Everything BMP280 Digital Pressure Sensor 300-1100 hPa I2C Mini Module

I have it attached to a NCD Control Everything 00I2C board for Onion,

Which has an Onion Omega2+ mounted on top

I can read it’s input for the temperature in Celsius and Fahrenheit through the provided python script of CE their GitHub (it’s a bit outdated though as there already exists python 3, but that’s not too important at the moment…)

Being totally new to python, I’m happy that I managed to read some results…
Only are these results quite off from reality.

Whilst an oldskool thermometer states that it is 19.70°C (67.46°F)
The BMP280 digital thermometer states that it is 21,17 °C (70.10°F)

So my question: Is there any way to calibrate these sensors so they give a preciser input?


Happy New Years!

The temperature accuracy of this sensor looks to be +/- 1.0 C. I’m not sure about the temperature accuracy of your other thermometer but if it is +/- 1.0 C as well then it’s possible that the difference of accuracy of the two could be as much as +/- 2.0 C.

There is no calibration for the sensor. If you search this document for calibration you will find that it is recommended that this be done via monitoring software rather than in the sensor itself. It sounds like you could simply subtract .93 C from the readings in software to bring it to the same level measured by your other thermometer. I would recommend doing this and taking readings at different temperatures to see if the range is linear at different temperatures.

Thank you,