AnsweredAssumed Answered

ADXL362 Inactivity Threshold Accuracy

Question asked by steveD1234 on Jan 11, 2016
Latest reply on Jan 11, 2016 by neilzhao



I'm using the ADXL362 for activity and inactivity detection.  Activity detection appears to trigger accurately at the correct threshold.  However, the inactivity threshold appears to be inaccurate by ~25%. 


A little more information about the configuration...

Range: +/-2g

Rate: 25Hz

Mode: Linked Mode with activity and inactivity detection and referenced activity selected

Activity threshold = inactivity threshold = 50mg, 500mg (two separate tests)

Inactivity Time = 1 second

Noise setting = "ultra low"


My test setup is on a shaker table where I have very good control of the frequency and amplitude of vibration seen on the device.  Inactivity occurs correctly when amplitude drops below about 20-25% of the set activity threshold after 1 second.  It may go inactive after 10 or so seconds if within 10-20%, and does not go inactive if within 10% of the threshold.


Please let me know if you have any thoughts, or can confirm that others have seen similar behavior.  Or if I can provide some more information about my setup.