Pebble let developers request HR data at a max frequency of 1Hz, so I'm not sure how you could calculate HRV from it (Nyquist theorem). https://developer.rebbl

Pebble let developers request HR data at a max frequency of 1Hz, so I'm not sure how you could calculate HRV from it (Nyquist theorem). https://developer.rebble.io/developer.pebble.com/guides/events-and-services/hrm/index.html https://developer.rebble.io/developer.pebble.com/guides/even... I also tinker with health data from wearables. I've built some Whoop-like UIs for a couple cheapo wrist straps from Aliexpress, but their HR monitors are always so bad that they're useless outside of when you're sleeping.