event "smartwatch taken on/off hand"

Hello!

Has anyone tried to identify the event when the smartwatch is "on hand" and when it is "on the table"? I am unable to use data from the HRM sensor. Raw and processed data is not suitable. The sensor is providing irrelevant data. The accelerometer is also not suitable for the case if the smartwatch is on the table on the train, for example. How quickly (3-5 seconds) to understand that the smartwatch is taken off your hand or on your hand?

Any ideas?

You can look at the diff field of the accelerometer to get an idea of the difference in accelerometer readings, but at the end of the day it could be a little tricky to tell the difference between a moving train and someone reading a book on a moving train.

On Bangle.js 2 there are some 'internal' HRM values reported in the HRM-raw event that could definitely be used for detecting when it's worn though

Hi Gordon,.

Thanks for the advice.
What HRM-sensor is used in BangleJS 2?
Can you send me the documentation for VC31 sensor? (even in Chinese)

It is the VC31 in the Bangle.js 2. I did get docs off the manufacturer finally but I'm not sure on the legality of sharing yet, i'll have to look into it

Hello.
Does BangleJS 1 use a V31 sensor too?

It uses a different sensor. The BangleJS1 hardware is described here https://www.espruino.com/Bangle.js+Techn­ical