[Feature Request]: Possibility to manually apply offset for temperature, humidity and barometric pressure measurements (BME280 and other sensors)

[Synthacon]

Platform

ESP32

Description

It would be useful to have built-in support for applying user-defined offsets to the temperature, humidity, and barometric pressure readings for the BME280 results. This sensor can't be recalibrated and humidity value drifts with the age. This option would allow users to easily adjust for systematic inaccuracies or environmental influences (e.g., heat from nearby components).

Correct for localized heating affecting temperature and humidity readings.
Adjust for known inaccuracies in factory calibration.
Enable quick fine-tuning for specific environmental conditions.

Just as example my sensor shows +0.64c and -10% for humidity and currently there is no way to adjust this.

[HarukiToreda]

this is indeed a problem plaguing most BME680 sensors as well, as they are not calibrated for accuracy at factory and there's no way to do so on the board itself. It must be offset by the firmware to be able to get accurate readings. All these sensors use temperature as a way to also calculate humidity and IAQ so having this wrong will lead to false readings all across the board rendering all inaccurate.

[dm5tt]

They are measuring the PCB temperature and not environmental temperature. So maybe they are working as designed?

If there's a LDO next to them they might heat up the entire board which will influence the temperature measurement.

[Synthacon]

It is the components on the board that are heating the PCB. Even short wires would probably cause the PCB to be heated by the Meshtastic device.

I would imagine that a simple offset adjustment in the software could be a solution, but posting this in the software section only resulted in the request being locked the next day.

The sensor data is also read very frequently. One reading every 1-15 minutes would be sufficient. Would be awesome to be able to adjust this also... Could reducing the reading frequency help remove the PCB heating? This would not resolve the issue if the wires are short, causing heat from the Meshtastic device to dissipate through the wires into the PCB.

Ultimately, implementing a simple offset adjustment in the software would be the easiest way to give users control and allow them to correct the values. There is x amount of heat dissipating trought the wires+components off the sensor PCB.

As now the whole idea of connecting sensors (tmp+humidity) is kind of pointless, nobody will ever get correct readings with the current options. There will be always huge error.

[fifieldt]

Not locked, just moved to discussion. I feel if the problem and fix can be better defined we might be able to do something.

[Synthacon]

Example about how this is solved in basic smart home Android app. It's just offset, not real calibration.