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

[ps_anu]

Thank you sitan . option 2 is good , i can go with this , actually i tried using timer to interrupt the sleep but i couldn't reach . i don't how to write the flow to interrupt the sleep using timer .. i have succeed upto checking the threshold using timer  .can you help me

[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