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SlimeVR / SlimeVR-Tracker-ESP

SlimeVR tracker firmware for ESP32/ESP8266 and different IMUs
Apache License 2.0
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BNO08X Calibration #211

Open TDW2401 opened 1 year ago

TDW2401 commented 1 year ago

I've noticed while spinning through BNO08X datasheets that it recommends a self calibration from the user For best motion tracking performance, it is recommended to calibrate the BNO08X. Since each MEMS sensor part has different individual characteristics, each device using the BNO08X must be calibrated individually. This seems to be a one time thing. Ceva suggests that even if this isn't done, the BNO will still work using factory calibration but I believe it could be worth a look in to if a user calibration could improve overall drift time. I would be interested to hear others opinions though.

Eirenliel commented 1 year ago

We also need to look into disabling auto-calibration some time after boot, since it may produce some unwanted results like broken accelerometer when stomping your leg.

nullstalgia commented 1 year ago

I have attempted to do calibration with my BNO085s due to experiencing unusual drift times (sometimes ~10-15 mins when just sitting down and talking).

What I would recommend based on my experience:

When you click on a tracker in the Home, there could be a button to "Start Calibration" that opens a modal that shows the BNO-reported "Accuracy" for Gyro, Mag, and Accel, and a "Save" button for when they're as high as it will go. (it goes from 0 to 3, 0 being unreliable, 3 being high reliability).

Animated renders or a demo recording of the calibration movements described in the datasheet or CEVA procedure doc 1000-4044 would be best for users.

In any case, as long as we don't tell the BNO to save the new calibration unless the user confirms it on the UI, we should be able to avoid most adventurous users accidentally goofing their trackers' calibration.