Pebble Vs Bangle

Thanks @Mr_Ploppy, that's great!

I've just looked at the datasheet and it says there's a maxiumum zero-g offset for the accelerometers of 90mg (or 25 typical) - so that's 8192*90/1000 = 737 maximum, or 205 normally!!

So it's hardly surprising that some people are finding the step count going crazy - @Mr_Ploppy's accelerometer isn't broken or defective, it's actually well within spec.

The datasheet (https://kionixfs.kionix.com/en/datasheet/KX023-1025%20Specifications%20Rev%2012.0.pdf) does hint that the offsets can be due to things like stress (so the PCB expanding/contracting slightly and squashing the accelerometer) so it may not even be something we can calibrate for as it may change depending on temperature.

So...

• what happens if we increase the threshold? It seems like it may be a benefit looking at those stats you posted. Sure, it has a 0.5% change during a walk, but for driving/housework/etc which were always an issue it's 50%+ better!
  
• Maybe instead of accMag-8192 we have a long-term average of accMag that we subtract? that way it effectively auto-calibrates.
  
  

I think I'd mentioned this at the time with this updated peak detector, but the old one required that the acceleration be below a threshold, then above in order to trigger - and I don't think it would have suffered as much with this. We could always look at doing a slightly different method of peak detection.

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