Why needs the soft device init so much time

RE: Why needs the soft device init so much time

run_ar — Wed, 03 Feb 2016 13:25:28 GMT

Looks like I'm down to about ~1.1ms when using SOFTDEVICE_HANDLER_INIT(NRF_CLOCK_LFCLKSRC_RC_250_PPM_250MS_CALIBRATION, NULL);
Compared to ~380ms when using
SOFTDEVICE_HANDLER_INIT(NRF_CLOCK_LFCLKSRC_XTAL_20_PPM, NULL);
Edit: It takes 250ms when using the external source because of a de-bounce timer. This timer is there to make sure the external crystal is settled, but it doesn't distinguish between a crystal or external "oscillator".

RE: Why needs the soft device init so much time

Markus Mueller — Wed, 03 Feb 2016 09:20:55 GMT

Setup: SDK: nRF52_SDK_0.9.2 SoftDevice: s132_nrf52_1.0.0-3.alpha_softdevice.hex. We have a 32KHz external clock from a second MCU which is already stable. How much faster would be the internal RC?

RE: Why needs the soft device init so much time

run_ar — Wed, 03 Feb 2016 08:23:24 GMT

Which Softdevice version are you using? Which SDK version are you using? are you using 32KHz external oscillator or internal RC? the RC would probably be faster.