About System off , System On, and sub power modes when softdevice present

[Tejal Jagdale]

Hello,

I am using NRF52832, SDK v15.1.0.

1. For entering into various  power down modes, does calling corresponding functions is enough to make entry  into these modes or are there any other points to be taken care  while calling these ? 
2. When BLE application is running, after calling respective functions, I am not getting expected difference in readings of current in different power saving modes. It will be helpful if you can explain these modes with respective code examples.

Thanks.

[WestCoastDaz]

Tejal Jagdale,

1. Yes, calling the correct functions is enough for entry into these modes.  It is up to you the programmer to setup up the correct wake up source before you enter system off unless you are using pin reset as the source.
2. Can you be more specific regarding the differences you are seeing and what hardware you are using?  This repository power down examples is a good resource for testing the various power down modes including disabling RAM blocks.

[Tejal Jagdale]

Without softdevice and BLE application I can observe readings as mentioned below:

system off : 1.8uA
Idle state: 3.3uA
Sleep mode: 3.3uA

But with softdevice and BLE application running I am getting constant 5mA reading.

[Jørgen Holmefjord]

How do you put the device in sleep mode with softdevice enabled? If you get ~5 mA, this indicate that the CPU is running and that the device is not put in system On idle mode. 

You should call sd_app_evt_wait in a loop in main to make sure the device is put in idle mode. You can also use the power management library.

[WestCoastDaz]

Tejal Jagdale,

As Jorgen said it sound like the micro isn't sleeping which is keeping the CPU awake.  It also could be related to the debugger as well.