Time-stamped event logging

[GT]

Hello Nordic,

For my application I need to log external and internal events/state of my device. In order to do so, I need to find a way to keep track on time. I do not have the option to use external RTC, so I need to rely on nrf51 peripherals. Additionally, my power budget is very tight so the more power efficient the solution is, the better.

I am using app_timer in my application code to schedule events. Is it good idea to base the timekeeping on this module as well? Would it make significant difference compared to a stand alone RTC implementation? Is there a standard way to approach such a task using nrf51?

Thank you for your time and effort! Any input will be highly appreciated!

Cheers, GT

[Øyvind Karlsen]

Hi,

You can base your timekeeping on the RTC, the application timer is based on the RTC, so in terms of peripheral power consumption you should see the same current.

Since the RTC is based on the low frequency clock, which runs from a low cost crystal, or alternately an internal RC oscillator you will not get good long term performance as the clocks will drift. If one of your devices has a stable UTC clock reference available, you could discipline the clock of your other devices. This all depends on what accuracy you need from your timing references.

Best regards,

Øyvind