Calibration 2: Per-Scanner RSSI Offsets doesn't work for me

[erkr]

I have a handful of mini esp32c3 boards. So I used one of them for the reference pair in calibration step 1.
That works great. Once I found good values for the reference power and attenuation, all these type of scanners showed similar results (I calibrated at 1 and 4 meters)

But then I started to calibrate the deviating scanners in step 2 (Athom plug v3, Apollo Air-1, Shelly gen3 mini).
For example the Athom plug, I started to adjust the RSSI at 1m (settled around -18). Then I verified the distance at 4m, but measured around 1.4m!

So I guess step 2 should allow to adjust the attenuation per scanner as well in order to get this right.

Note: orientation of both the device and scanner influence the distant substantially (2 times easily). Guess that is a given, so used the same orientations in step 2.

Best Eric

[agittins]

The attenuation is "meant" to be environmental, not device-specific - so a per-device option is against what it's meant to be used for, but more importantly - will probably lead to more support questions! :-)

What happens if you instead calibrate the Athom plug at 4m? Things tend to be very sensitive to changes at longer distances, so for step2 taking "a longer view" will typically work better.

[erkr]

Thanks for answering, I tried that as well.
The distance near the device will become a little more than the actual distance. At larger distances the reported distance remains relatively to short.
The issue remains that the scaling of the signal strength vs distance simply is extremely off for two devices. I ended up with -30 for correct readings at 3 meters

I would really prefer calibration step 1 for all devices. It's a little effort to copy the values for identical devices