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ADXL362 Interrupt questions and weird behaviour

Question asked by emil@iconsultable.no on Jun 16, 2015
Latest reply on Aug 11, 2015 by emil@iconsultable.no

Using the EVAL-ADXL362Z

Hi, I try to reliably detect an inactivity and activity on INT1. It seems to work OK, but then something weird happens. Inactive is triggered again, and again forever. It times out in the "inactive time" (0x25), and the fires the interrupt again. I expect each event to fire once. If I never touch the sensor, it will just send inactive interrupts at every given interval set in 0x25 reg. Never "Active", unless I turn it of course.

Awake flag is always true! Isn't it supposed to go off when inactivity is detected?

 

ACT_INACT_CTL 0x27 - LINK_LOOP(LINK_MODE) | ACT_EN | INACT_EN | ACT_REF | INACT_REF

 

Interrupt setup

INT_ACT_EN | INT_INACT_EN | INT_LOW_ACTIVE  // active low, interrupt on active, inactive.


I have triple checked that the bitflags are correct according to spec.


If I run it in LOOP_MODE it seems to behave correctly. But matter how long I sleep between start measurement and set interrupt, it will generate one Awake = 1 and Awake = 0 before becoming quiet. Awake goes from 0 to 1, and then back to 0 after the inactivity timeout.


Also INT2 never goes to low. I supply 2.8V but, it never goes lower than 1.7 on "low". There's ~2MOhm resistance between VIO and INT2. Is this normal? I was very careful soldering this thing. Is it broken? It also seems to be very sensitive to cabling etc.

 

Thanks.

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