Re: How is old M7/M8 data handled in Health app?
Thanks for your post and for bringing up the idea it could overwrite the M7/M8's data after gathering the data. I couldn't have thought of this.
With this in mind, I tried this :
1. Launch the Health app and let the data be gathered.
2. Download and Launch a Pedometer app, using solely M7/M8 data (it's basically an app to read what's stored in M7/M8).
At this step, the Pedometer app still shows the data from M7/M8, so it's not erased after Health read it.
3. Go back to Health and delete some samples.
4. Delete and re-download a fresh Pedometer app.
The Pedometer app still shows the same number of steps. Therefore, deleting samples in the Health app doesn't delete data in the M7/M8.
5. Go back in the Health app and check the data.
The data is unchanged. What I mean is the deleted samples are not sync'd back, even though they're still on the M7/M8 chip.
These are my conclusions up to now. However, I'm still really wondering what happens to all the old samples, if they're combined automatically or not... Because I have an indecent number of samples already, most of them with a small increments (like 5 steps at a time, and not 200, making the number of samples be incredibly huge).
If anyone had more info about how old samples are handled, or just general knowledge about the Health app, I'd love to hear from you!