Please post what you're working on!

Thx for the thoughts, you're right that probably the accelerometer is
the best choice of course. ADXL345 has free fall detection, I am
currently investigating this. The problem is that the puck is such a
nice package, even a lanyard can be attached. Now the extra cables for
the accelerometer will require new 3d printing for another case, etc.

I have two choices, Freescale MMA8653FC (why is a "bit" complicated) and BNO055 as I have heard it is easy https://learn.adafruit.com/adafruit-bno055-absolute-orientation-sensor/overview

https://www.tindie.com/search/#q=BNO055

As such, mag and accel in one small tight package and is "interesting" if it works.
I receive a ND0055 Arduino shield soon, and will be trying it against nRF52-dk and probably a puck.js (documentation)

This package is nice and square https://www.tindie.com/products/onehorse/tca9548a-i2c-multiplexer/?pt=full_prod_search

This package is nice and round with processor https://www.tindie.com/products/FabLab/the-sensable-thing-pico-platinchen/?pt=full_prod_search

https://www.tindie.com/products/onehorse/bno-055-9-axis-motion-sensor-with-hardware-fusion/