LIS2MDL prevents nRF52833 from staying in SYSTEM OFF

[feathers]

I am using the common application framework of the nrf connect sdk. Specifically, I am testing the power manager module to put the board in OFF mode.

However, there is an issue whenever I include the node corresponding to the LIS2MDL magnetometer in my overlay file and I enable CONFIG_SENSOR and CONFIG_SPI.

Even if the board goes to sleep successfully, it will get awoken again within a second by what I can only assume is data coming in from the sensor which triggers a GPIO signal.

This behaviour simply does not happen when CONFIG_SENSOR is disabled, or when my overlay file does not include the LIS2MDL.

For reference, the board also has a LSM6DSO attached to the same SPI interface, which does not reset the board once in SYSTEM OFF.

Checking the LIS2MDL zephyr driver I noticed that it is supposed to handle suspension on its own, but clearly this is not happening.

Any help will be appreciated.

Kind regards,

feathers

[feathers]

I have finally found a solution. While powering off the board, there was a stack overflow on the idle thread. This can be solved by adjusting the IDLE stack size.

CONFIG_IDLE_STACK_SIZE=1024

This occurs because the LIS2MDL driver performs some actions before going to SYSTEM OFF as I understand.

Thanks to Jørgen Holmefjord for the inspiration to check the RESETREAS register and the log of the dev kit.