It seems you can just look at the acceleration magnitude and see when it goes above/below 1g by some threshold - seems to work moderately well. That's what Bangle.js does anyway
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
https://banglejs.com/reference#l_Bangle_step :)
It seems you can just look at the acceleration magnitude and see when it goes above/below 1g by some threshold - seems to work moderately well. That's what Bangle.js does anyway