Wake on Significant Motion

[scath999]

Wondering how I can configure this device to fire an interrupt on significant motion, per page 45 of the datasheet (here)?

The goal is to be able to set an alarm in CPy to wake when pin D3 is set high - according to the schematics for the Feather Sense (which I'm developing on), this is the GPIO connected with INT1 on the LSM6DS33.

Something like

pin_alarm = alarm.pin.PinAlarm(pin=board.D3, value=True, pull=True)
alarm.light_sleep_until_alarms(pin_alarm)

The datasheet seems to indicate that setting register 0x0D on the device to 64 (bin 01000000) will accomplish this.

Thoughts?

[tekktrik]

Looks like this should be an easy addition. I don't have the hardware but I can submit a PR with this functionality if you'd like to help me test it!

[tekktrik]

I plan to get one anyways to work on some other issues, so no worries!

[caternuson]

Seems related to:
#5
which I appear to have totally forgotten about and abandoned. :(

@tekktrik I can try picking this up. There's a similar outstanding issue on the Arduino side as well.

[tekktrik]

Sounds good! I was going to see about doing #17 so I can just try that when the sensor arrives!

[caternuson]

This library supports multiple devices with a common base class LSM6DS defined in __init__.py. There is some variability in the enabling and use of Significant Motion Detection between the devices. Here's a summary taken from several app notes.

---

LSM6DS33 (?? guessing ??) STM doesn't seem to acknowledge its existence anymore
LSM6DS3TR-C (AN5130)

---

ISM330DHCX (AN5398)
LSM6DSOX (AN5272)
LSMM6DSO32 (AN5473)

[caternuson]

@scath999 In AN5398, it describes the "significant motion" detection as:

It generates an interrupt when the difference between the number of steps counted from its initialization/
reset is higher than 10 steps.

Is that what you are expecting? Or were just wanting something like shake detection?

EDIT: Also checkout the comment here:
#5 (comment)
It may not be what you're expecting it to be?

[scath999]

Hi Everyone,

Sorry for the late replies - busy at work.

I've managed to solve this issue for now by creating a Pin.Alarm on D3. This works, though less well than I'd like: The sensor has to be moved pretty quickly and repeatedly to wake.

Thoughts?

[scath999]

@scath999 In AN5398, it describes the "significant motion" detection as:

It generates an interrupt when the difference between the number of steps counted from its initialization/
reset is higher than 10 steps.

Is that what you are expecting? Or were just wanting something like shake detection?

EDIT: Also checkout the comment here: #5 (comment) It may not be what you're expecting it to be?

Exactly - @ladyada is having the same experience I'm having.