http://bentasker.i2p/posts/blog/software-development/extracting-data-from-zepp-app-for-local-storage-in-influxdb.html
If activity is detected, the watch will start taking more frequent readings (though only 1-per-minute will make it into the data_hr attribute). I haven't yet figured out what the values in the data attribute represent: I'm not currently getting meaningful values back, suggesting that they pertain to something I'm not using (or that, perhaps, the Bip 3 doesn't support).