What are the Low power mode for the nrf connect SDK

[jyoti yadav]

Hi,

Could you please guide on the modes for the low power mode which one is to select?

Requirement is when the particular gpio is low need to go to the low power mode and for come out of it gpio pin should be high.(interrupt for the detecting low and high)

Before entering into low power mode need to copy some data from ram to flash, all the peripherals should be off in low power mode and RTC should be ON always.Could you please suggest the suitable mode for the requirement

I have gone through the example code there i have tried the SYSTEM_OFF_MODE but at the time of exit it will do restart. We need the RTC keep running so any other mode is there which will not restart while exit from the mode ? Any example code where we can understand and explore the different mode? In the nrf52833 i can see only SYSTEM_OFF_MODE is there in power.c and there is lot many mode in zephyr (Standby, system to ideal ) can we use this modes for the nrf52833 if yes how i can achieve this?

I am using the nef connect sdk 1.9.1 version

Thanks.

  

[Vidar Berg]

Hi,

The scheduler will automatically enter the idle thread when there is no work to do, and this thread will make the chip enter System ON mode. 

Expected sleep current in System ON with RTC active can be found here:  Sleep 

I have gone through the example code there i have tried the SYSTEM_OFF_MODE but at the time of exit it will do restart.

System OFF mode is only suitable if you want the chip to be powered off for a longer period of time and have an external wake-up source. For example, a pin interrupt.

Best regards,

Vidar

[jyoti yadav]

Can you please provide the example code for the SYSTEM_ON_MODE which i can refer. And i can see 

PM_STATE_ACTIVE,PM_STATE_RUNTIME_IDLE, PM_STATE_SUSPEND_TO_IDLE,PM_STATE_STANDBY,PM_STATE_SUSPEND_TO_RAM, PM_STATE_SUSPEND_TO_DISK,PM_STATE_SOFT_OFF what are those mode for the we need to write the device driver for this mode . because i can see in the nrf52 Power.c file there is only one mode that is this SYSTEM OFF mode is possible to implement other states?

[Vidar Berg]

We haven't implemented the other power modes for the nRF52 series because our hardware features built-in automatic power management, which requires less software intervention than other architectures.

https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/test_and_optimize/optimizing/power_general.html#general-recommendations 

[jyoti yadav]

For the SYSTEM OFF MODE how we can sure about it is really in the system off mode any register we can see for this?

[Vidar Berg]

The chip is powered down in System OFF so you can't really read any registers in that state. However, you can read the RESETREAS register on startup to confirm that the chip has been in System OFF mode.

[jyoti yadav]

For the SYSTEM ON mode can we have any example? how to enable the system on mode is there is any API?  In the system on mode all the peripheral are inactive or we need to suspend them? 

[Vidar Berg]

I'm not aware of any example that doesn't go to System ON so you can just choose a SDK example you want to use.

Vidar Berg said:

The scheduler will automatically enter the idle thread when there is no work to do, and this thread will make the chip enter System ON mode. 

For instance, the idle thread will be entered if you call k_sleep() from your active threads.

jyoti yadav said:

In the system on mode all the peripheral are inactive or we need to suspend them? 

It depends on what peripherals you've enabled. I would recommend you try to measure the actual current consumption on your board first.