LIS2DE12 - is it possible to set & reset INT1 & INT2 pins (or any other pin) on wakeup

[MŠirc.1]

Hi,

I was looking at LIS2DE12 and I am aware that it can send a wakeup signal to the CPU. In my design I want to enable the power on PMIC chip directly through its enable pin. So I want to do something like this:

• Shake the device
• LIS2DE12 sets its pin to 1 (3V)
• this pin in is connected to PMIC which now powers up the main CPU
• when the device is not moving the main CPU sets the reset signal to LIS2DE12
• LIS2DE12 sets its pin to 0 (0V)
• PMIC powers down the CPU

I read about latching INT1 & INT2 in the specification paper but I am not sure this means this. I also found https://community.st.com/s/question/0D53W000012QA5NSAW/lis2de12-interrup-on-wakeup but I am not sure if the same case is described there.

Is it possible to make such operation? Just set some pin to 1 when wakeup is triggered and then reset it with another pin.

If this is not possible LIS2DE12 is there any other IC that works like this?

Thanks,

Matej

[Eleon BORLINI]

Hi Matej @Matej Šircelj​ ,

Yes, the procedure you are describing should be possible.

For this step:

• when the device is not moving the main CPU sets the reset signal to LIS2DE12

in the latched interrupt case, you have to read the INT1_SRC (31h) register to clear the interrupt itself (see datasheet, p.21).

Only a remark: I suggest you to use a more recent part number than the LIS2DE12, such as the LIS2DW12, which is guaranteed for more years.

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-Eleon