ADXL345 has AC-coupled mode for both ACTIVITY and INACTIVITY interrupts. According to the datasheet, this is how reference values are defined:
"In ac-coupled operation for activity detection, the acceleration value at the start of activity detection is taken as a reference value."
My question is:
For example, if I only enable ACTVITIY interrupt in the AC-coupled mode with a threshold of 0.5g. The purpose is to if the orientation of the ADXL345 is constantly changed, assuming the ADXL345 is embedded into a watch and I want to know if the user's wrist is moving. Does it mean that this reference value is only taken once, the moment I activated the ACTIVITY interrupt? Or every time an ACTIVITY interrupt is generated, a new reference value is taken?
Thanks for any inputs.