joe holdsworth

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8 years, 3 months ago.

nRF51-DK Real Time Clock implementation

Could I put a request in to enable the Real Time Clock function on this platform? Is there a plan to implement it? Has someone already done it?

Joe,

There is a hack out there, nrf51_rtc . It works, but since it's not part of the "official" mbed release, it does have a couple of quirks that I am aware of:

1. It does not properly timestamp files using SDFileSystem. All files are stamped 01/01/2098 00:00:00

2. The RTC always starts at 0 at reset, even if you have set the RTC before resetting the nRF51.

With that said, the nRF51 has a very accurate RTC compared to other mbed controllers. Accurate to within 1 second per day has been my experience.

...kevin

posted by Kevin Braun 13 Jan 2016

Thanks Kevin, so what interrupt updates the rtc? As I understand it that code updates rtc in the main loop, I'm looking for rtc still running with just rtc part of chip powered up...

posted by joe holdsworth 13 Jan 2016

Ah apologies Kevin I just had a look at documentation, so the only way to keep RTC going with lowest power consumption is in WFI sleep mode which I assume happens when CPU is sleep'd as in the example.

I was expecting there to be a way of just running the RTC alone without any power to rest of MCU.

Did you conclude the same thing...

posted by joe holdsworth 14 Jan 2016
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Assigned to Martin Kojtal 8 years, 3 months ago.

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