en/calibrate-sensors-esphome/

[giscus[bot]]

en/calibrate-sensors-esphome/

Whether you have changed the firmware of a Wi-Fi device with an ESP8266/ESP32 type chip, or if you have created your own device with different sensors, you will have noticed that the measurements of some sensors are not very real. Many sensors do not require any extra configuration from us, they just work and give their value, but others may come with a slight deviation from factory.

https://www.danielmartingonzalez.com/en/calibrate-sensors-esphome/

[readstead]

Do you realize that you entered your calibration data into the esphome yaml backwards? You did REFERENCE -> MEASURED, when it’s supposed to be MEASURED -> REFERENCE. So all of your data is going to be wrong in the exact opposite direction you want.

[danimart1991]

I think the confusion it's a translation problem in the post.

[mprowe]

Hi Daniel,
In your introduction you say this: "With the original firmware they come calibrated to avoid sensor drift, but by changing your system to ESPHome we lose that calibration."
Can you expand on this statement? And in particular, how it will effect i2c devices. ie BME280.
Regards, M.

[danimart1991]

Hi @mprowe

The need for a calibration depends on the sensor, for example, the BME280 is rarely out of calibration and although a small adjustment may be necessary, it is not normal. These sensors already have a calibration performed at source and their software calibration is usually negligible.

Others, for example, consumption measurement sensors, do require software calibration, and that is the motivation for this article.

[mprowe]

My question is regarding "Why does esphome cause bmp280's to report erroneously"? Do you know? Is it faulty programming?
For example, I have four bme280's. Using Arduino code all 4 report temperatures within 1 degree of a reference. However, when being read via esphome code, none are close to the reference temperature. One is over 15 degrees C high!

[danimart1991]

Strange, the configuration of bme280/bmp280 is quite easy. Try modifying the iir_filter parameter.