I want to minimize current consumption by switching from NORMAL to Low Power Mode 1 and to detect no-motion simultaneously.
That works. But when I'm trying to move BMA280 continually, no-motion interrupt is fired despite the fact that motion does persist. Tested with sleep_dur 0.5ms, 500ms, 1s. In NORMAL mode I see no interrupts by moving the device, and I do see no-motion interrupt when BMA280 is motionless.
Is that expected behaviour? Can I use no-motion & LPM1 together or not?
Hi,
You are right. You don't need to use no_motion interrupt. You can just use any_motion interrupt.
No_motion interrupt uses both internal timer and any_motion detection. But it consumes a lot of current. If there is no any_motion, then the timer starts counting for example 5 seconds or 10 seconds based on your configuration. If there is any_motion happening during the timer counting, then the timer will get reset and start counting again whenever there is no any_motion again. If it is true that there is no any_motion for the timer duration, then no_motion interrupt will be generated. This can save your MCU's effort to determine if your device is stationary or not.
It is true that you can use your MCU's own internal timer to replace no_motion interrupt and only use any_motion interrupt.
Thanks.
