A friend of mine is looking for a way to monitor their heart beat in real time on their Fenix 6. As in, see a blinking icon (or whatever) that is actually in sync with each individual beat.
As near as I can tell, this is not possible for a watch face or data field, both of which are limited to drawing once per second. Maybe an app or widget can do it, I'm not sure.
It seems like two things would be needed:
- Updates from the hear-rate sensor that are (close to) real-time. Presumably using registerSensorDataListener. Is there any documentation or general knowledge about the latency and consistency of this API? Or a different way to get precise timing of beats?
- Calling requestUpdate() more than once per second and getting onUpdate called with a predictable delay. The docs don't seem to say if there are limits or SLAs.
Also, does the use of an external hear rate strap vs the watch's own sensor make a difference?
I will do some experiments and see if I can get an idea of what's possible, but it would be great if anyone has experience to share.
Thanks!