BME680: Accuracy returns 1

[Darius_m31]

Hello,

we observe in several cases that accuracy 3 is reached and IAQ is reported (for hours or days) but suddenly accuracy returns 1. A IAQ variation seems necessary to return to accuracy=2 and then 3.

Is it an expected behaviour?

Is there a way to avoid or reduce this behaviour?

Thanks

[o_o]

Hi Darius,

The accuracy indicator on a scale of 0-3 is an artifact of Google's Android API definition.

https://developer.android.com/reference/android/hardware/SensorManager.html#SENSOR_STATUS_ACCURACY_H...

For BSEC the meaning is slightly different. It is akin to a calibration status. There a multiple other threads on this forum describing it in more details, but the short answer is that it is expected to periodically drop to 2/3, but 1/3 means that the input data does not fluctuate very much. You can increase the time constant from 4 days to 28 days in this case. (by changing your config string)

o_o

[Darius_m31]

Thanks for the information,

however, we observe accuracy 1 even if the VOC is varying.

Placing 2 devices in the same position, we have observed that:

- in one device VOC raises from 25 to 200 (in 4-5 hours) keeping accuracy at 3;

- while in the other device the initial value is the same, but we have 2-3 hours of accuracy=1 and eventually accuracy gets 3 with VOC aligned to the other device.

Regards,

Dario