how to wake up the device by using threshold

[ps_anu]

hi ... i am using nRF52832 ,i want to save the battery so i am planning to use system off mode . how to wake up the device from system off mode using threshold value or either system on mode 

is it possible ? how to do 

Thanks in advance

[Stian Røed Hafskjold]

In system OFF the chip can wake up by the ANADETECT signal, created by the LPCOMP peripheral: http://infocenter.nordicsemi.com/topic/com.nordic.infocenter.nrf52832.ps.v1.1/power.html?cp=2_1_0_17_1#unique_1707892264

And from the LPCOMP peripheral:

The LPCOMP can wake up the system from System OFF by asserting the ANADETECT signal. The ANADETECT signal can be derived from any of the event sources that generate the UP, DOWN and CROSS events. In case of wakeup from System OFF, no events will be generated, only the ANADETECT signal. See the ANADETECT register (ANADETECT) for more information on how to configure the ANADETECT signal.

http://infocenter.nordicsemi.com/topic/com.nordic.infocenter.nrf52832.ps.v1.1/lpcomp.html?cp=2_1_0_38#concept_tdv_zkx_lr

And here is an example in the SDK demonstrating the use of LPCOMP: http://infocenter.nordicsemi.com/topic/com.nordic.infocenter.sdk5.v15.2.0/lpcomp_example.html?cp=4_0_0_4_5_17

[ps_anu]

Can we wake up by using threshold value

[Stian Røed Hafskjold]

If you are successful in checking the threshold using timer, there's not really much more to do. The CPU automatically goes to IDLE between the interrupts, as long as there is a __WFE() in the main loop somewhere. Can you post your main function, then I can have a look.

[ps_anu]

 */
int main(void)
{
bool erase_bonds;



    // Initialize.
   
    uart_init();
    log_init();
    timers_init();

    ret_code_t err_code =app_timer_create(&m_led_a_timer_id,   APP_TIMER_MODE_REPEATED   ,timer_sensor_event_handler);
APP_ERROR_CHECK(err_code);

    buttons_leds_init(&erase_bonds);
    power_management_init();
    ble_stack_init();
    gap_params_init();
    gatt_init();
    services_init();
    advertising_init();
    conn_params_init();

  printf("\r\nUART started.\r\n");
    NRF_LOG_INFO("Debug logging for UART over RTT started.");

    advertising_start();

    err_code = app_timer_start(m_led_a_timer_id,APP_TIMER_TICKS(60000),NULL);
  APP_ERROR_CHECK(err_code);
 


     

twi_init();
 MAX30_set_mode();
    // Start execution.


   

        

      for(;;)
             {
idle_state_handle();

      
      }
      }
              
   
        

[ps_anu]

 In  time event handler i am comparing threshold 

[ps_anu]

Is it possible for option 1 . if manually  i am setting threshold in my program , and by using led pin

[Stian Røed Hafskjold]

Ok, so I think you are finished with you code now. It goes to sleep in the idle_state_handle() and wake up using app_timer interrupt.