Nrf9160 RTC specs anywhere?

RE: Nrf9160 RTC specs anywhere?

Cyril — Mon, 21 Jan 2019 09:05:19 GMT

Hello,
I think you can rely on having the MCU draws about 3uA while keeping the calendar active.
https://www.nordicsemi.com/DocLib/Content/Product_Spec/nRF9160/latest/_tmp/alta-nRF9160/autodita/CURRENT/parameters-id_current_sleep

I never used Zephyr, but looking at the documentation, you can configure Zephyr to several power modes: https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/zephyr/subsystems/power_management.html

You should try that example and measure current: https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/zephyr/samples/subsys/power/power_mgr/README.html

To my mind, there is no need for an external RTC.

Best

RE: Nrf9160 RTC specs anywhere?

rkguy — Sat, 19 Jan 2019 19:43:39 GMT

Thank you. While this answers the original question, do you have an opinion on whether it is more worthwhile to try to implement a date time clock using RTC counters or just get an external rtc clock? Specifically, while I like less components I am wondering if keeping a timestamp calendar using just the 9160 will severely impact battery life?

Here are relevant links

https://github.com/NordicPlayground/nrf5-calendar-example

And an older one

https://devzone.nordicsemi.com/f/nordic-q-a/2107/nrf51822-long-time-timekeeping

The other concern is how hard it would be to port this logic to work with Zephyr.

Looking for informed opinions

RE: Nrf9160 RTC specs anywhere?

Joakim Jakobsen — Wed, 16 Jan 2019 10:17:32 GMT

Hi.

You can find the documentation on our website https://www.nordicsemi.com/DocLib

I believe the documentation you are looking for is;
nRF9160 OPS - RTC - Real Time Counter
NRF9160 OPS - Clock Management

Let me know if there is anything else you are looking for.

Best regards,
Joakim

RE: Nrf9160 RTC specs anywhere?

Cyril — Wed, 16 Jan 2019 10:07:56 GMT

I guess what you are looking for is in:

https://www.nordicsemi.com/DocLib/Content/Product_Spec/nRF9160/latest/rtc
https://www.nordicsemi.com/DocLib/Content/Product_Spec/nRF9160/latest/pmu_oscillators