Many thanks for the answer. "The choice of using a crystal or not in the microcontroller is up to you, and the benefits of a more accurate clock vary per application." This is about that what Adafruit writes. The accuracy is probably most interesting when it comes to "drift reduction", so if you have some rough percentage estimates of drift differences (with/without crystal) at more or less fixed temperatures, it would be great to hear. Herbert (https://community.bosch-sensortec.com/t5/MEMS-sensors-forum/BNO055/m-p/7730/highlight/true#M638) was investigating drifts, but unfortunately in this reply he didn't compare the case with and without crystal.
... View more
