Gesture on Bangle JS 2

The best thing really is to check the code at https://github.com/espruino/Espruino/blob/master/libs/banglejs/jswrap_bangle.c#L1638 but...

Difference in acceleration compared to the previous data point?)?

Yes, it's this. It's the difference in raw acceleration values.

The sqr stands for squared - it might be worth checking with Bangle.getOptions to see what the values are originally, but gestureStartThresh should have a default of 800*800. (I can't remember now why we square them and don't use them normally, but I think it's historical)

Chances are it broke because the value was 800*800 and you set it to 800?

So:

• gesture starts when accDiff > gestureStartThresh
  
• gesture ends when accDiff < gestureEndThresh for at least gestureInactiveCount samples
  
• if there are less than gestureMinLength samples we ignore it