SOFTDEVICE_HANDLER_INIT duration

[Olivier Scalbert]

Hello,

I am doing some tests with the Heart Rate Service Sample Application for the nRF51822 evaluation board (PCA 10001). Inside the ble_stack_init(), there is this call: SOFTDEVICE_HANDLER_INIT(NRF_CLOCK_LFCLKSRC_XTAL_20_PPM, false); And this call takes 350ms. Is there a way to decrease this duration ? I am still using v5_1_0 sdk.

Thanks,

Olivier

[Håkon Alseth]

Hi Olivier,

The reason why this call takes so much time is because it will start up the 32 kHz source (external X32k takes up to 1 second).

If you use "NRF_CLOCK_LFCLKSRC_RC_250_PPM_8000MS_CALIBRATION" instead, it will shorten the start-up time, but will increase the average current consumption.

Best regards Håkon

[Olivier Scalbert]

It works ! Thanks you so much !

For your info, I am doing an experiment with two pca10001 boards, one with s110 and one with s120. The one with s120 is always on. When I poweron the s110 one, the connection is established with the s120 110ms later. That is fast. Cool !!

Best regards,

Olivier

[Anand Ramashetty]

Hi Håkon,

I am also facing the same issue. for me ble_stack_init() is taking almost 500 msec. when i changed the NRF_CLOCK_LFCLKSRC_XTAL_20_PPM value to NRF_CLOCK_LFCLKSRC_RC_250_PPM_8000MS_CALIBRATION ble_stack_init() function taking 2.820 msec, it reduced to almost 497 msec.

Since power consumption is also one of the main parameter, what is the average current consumption is for the above two macros ? what is the difference in current consumption ?

One more thing, In my application, ble_stack_init() has the following function called.

1. SOFTDEVICE_HANDLER_INIT(NRF_CLOCK_LFCLKSRC_RC_250_PPM_8000MS_CALIBRATION, false);
2. err_code = sd_ble_enable(&ble_enable_params);
3. err_code = softdevice_ble_evt_handler_set(ble_evt_dispatch);
4. err_code = softdevice_sys_evt_handler_set(sys_evt_dispatch);

can i optimize this further to reduce the time still more?

Regards, Anand