Programming DK board button to go to system on low power mode and then wake & advertise on consecutive button presses

RE: Programming DK board button to go to system on low power mode and then wake & advertise on consecutive button presses

Simon — Mon, 09 Sep 2019 14:09:15 GMT

The function sd_app_evt_wait() will not block the RTC. I think you are mixing system OFF mode and system ON mode.

System OFF mode will put the device into the deepest power saving and disable all peripherals (including RTC)
System ON mode will put the system in a lighter sleep mode where all the peripherals can be used (including RTC). To put the device into system ON, you call sd_app_evt_wait().

Read this Devzone ticket for more information about this.

I would recommend you to remove the call to sd_app_evt_wait() in the bsp_event_handler(). In your code, the chip is already set up to go to sleep. It is done through idle_state_handle()-->nrf_pwr_mgmt_run()-->sd_app_evt_wait(). The program flow works in this manner:

The call to advertising_start() can still remain in bsp_event_handler(), but you should create a boolean variable that checks if advertising is ongoing or not. Set variable to true when advertising is started, and set it to false when advertising is stopped.

Best regards,

Simon

RE: Programming DK board button to go to system on low power mode and then wake & advertise on consecutive button presses

thoric_fish — Wed, 04 Sep 2019 16:57:22 GMT

Hi, for my application the NRF should not power off as I need the RTC to be active, so the RTC should stay on until the NRF runs out of battery. My application also requires that BLE advertising only start when the user presses a button.

I commented out bsp_btn_ble_sleep_mode_prepare() and the problem still persisted. I made some more modifications and it turns out that if I press the button twice while BLE advertising is still active from the first advertising_start() call in main() then there is another call to advertising_start(). It seems like one or more calls to advertising_start() while BLE advertising is already on will generate errors. I will investigate some more.

RE: Programming DK board button to go to system on low power mode and then wake & advertise on consecutive button presses

Simon — Wed, 04 Sep 2019 09:28:28 GMT

Is there a reason why you're not only using the initial solution? With idle_state_handle() inside the for loop.
Could you try to comment out err_code = bsp_btn_ble_sleep_mode_prepare(); in sleep_mode_enter() and see if the problem still persist?

Best regards,

Simon