RTC Setting of Nrf51822

RE: RTC Setting of Nrf51822

BK — Tue, 23 May 2017 11:25:15 GMT

Thanks Jorn

RE: RTC Setting of Nrf51822

Jørn — Tue, 23 May 2017 07:04:21 GMT

That looks correct, yes.

RE: RTC Setting of Nrf51822

BK — Tue, 23 May 2017 05:30:20 GMT

Hi Jørn, Sorry that I made a mistake, the MCU connect a 16MHz crystal at port XC1,XC2 and a 32.768KHz crystal at XL1,XL2 as well. The tolerance of the crystal is as below. So in this case, I need to set it as this: SOFTDEVICE_HANDLER_INIT(NRF_CLOCK_LFCLKSRC_XTAL_20_PPM, false); is that correct?

RE: RTC Setting of Nrf51822

Jørn — Mon, 22 May 2017 14:20:41 GMT

Hello BK

When the 32.768 kHz crystal is not present you can choose between two low frequency clock sources. Either the internal RC oscillator, or a synthesized low frequency clock created from the high frequency clock. Do note that the synthesized clock has a higher current consumption, and the high frequency clock must be running at all times. You can read more about these choices here.

Best regards

Jørn Frøysa

RE: RTC Setting of Nrf51822

BK — Mon, 22 May 2017 13:47:09 GMT

Hi, just the 16Mhz crystal. As for the tolerance, I'm not pretty sure about it...which configuration do I need to set in ble_stack_init() for my case?

RE: RTC Setting of Nrf51822

Jørn — Mon, 22 May 2017 13:40:22 GMT

Do you have a 32.768 kHz crystal as well, or just the 16 MHz crystal? And what tolerance do you have on your crystal?