BMI160 No Motion Interrupt Duration

Hi,

I currently have the no motion interrupt working fine as long as the duration is set to around 10 seconds or below, if i set the duration any higher than this there seems to be some sort of offset being applied causing a duration setting of 60 seconds to trigger at around 6 miniutes. So really im just abit confused about the maths used for the duration setting, I had a read of the data sheet and found the stuff relating to the slow/no motion duration delay equations however i couldnt really make much sense of it in all honesty.

My IMU is currently set up like:

ODR: 25HZ

Range: 16G

BW: NORMAL_AVG4

power mode: Normal

I would greatly appreciate any help to aid my understanding of the maths involved/issue if there is one, surrounding this.

Thank you in advance!

Best reply by AlexC

Hi,

Sorry to double post but i believe I have sorted my problem by having a more detailed read through of the data sheet and look through the bmi160 code hosted on github. I noticed that there are only 6 bits used for the duration and combined with the different tick times of 1.28, 5.12 and 10.24s explains why im getting weird times as a settign of 40 using a tick time of 5.12 would mean it triggering after around 3 mins. Unfortunately this means the max duration time i can have is around 7 mins, which wont work for my intended use so I will have to come up with a custom way of detecting no motion.

Many thanks for your assistance.

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