Low power modes

[vinaysingh]

Hello Nordic team,

We are making our own custom project, and we are facing problems in implementing lower power modes.

Reading from the info center, when the DK Board is in system_on mode it is consistently in sleep mode.

Note : I have dumped the ble_app_templete project.

Questions 

1.) But then also it consumes more power consumption which is different from as mentioned in datasheet ?

2.) Pls share something to understand how the low power mode works in the Firmware ?

3.) And suggest any example how to attain least power ?

Thank You !

[Simonr]

Hi

1. The nRF52 series SoCs has three "main" power consumption modes. "Regular" system ON mode, which it uses when the application is running, this generally draws quite a bit of power compared to the low power modes. System ON IDLE mode, this is typically the Ultra-low power modes described as System ON in our PS. Finally, we have the System OFF mode, which turns the CPU off completely and uses the least power.

2. In our SDK, we havea couple of "common" functions for dealing with these sleep modes. By default the device will be in the System ON mode. To put it in IDLE mode, we generally use the idle_state_handle() function in the SDK which handles pending log operation s before calling the nrf_pwr_mgmt_run() function that uses the power management library to put it into idle mode.

This goes for system OFF mode as well, which can be reached by calling the sleep_mode_enter() function, which prepares the device for system OFF mode before turning the CPU off.

3. The ble_app_pwr_profiling or power management examples both show how to minimize current consumption.

Best regards,

Simon

[vinaysingh]

Hey Simonr, sorry for late reply !

I have few questions more :-

1.) In System On mode, when there is no event pending then the device is in IDLE mode.

a.) But what should we consider when the BLE Device is connected to and mobile App, it is also event going on right ?

b.) So In which Low Power mode the BLE device will be in ? 

2.) If any timer is running and executing any Object handler, then that time the device will be in System ON IDLE Mode ?

3.) Can you please share something, How IDLE Mode is implemented in System ON State ?

(I am not able to understand, how exactly the SYSTEM ON IDLE Mode is implemented)

Thank You !