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Kratos
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Time is "remembered"

Fri Nov 13, 2015 1:06 pm

I noticed that with the sense-hat plugged into my pi, the pi seems to remember what time it is, even if not connected to a network. The time is a little off, about 15 minutes slow. How can this be if the sense-hat has no RTC? Or does the pi itself remember the time?

Kratos
I have posted mostly with a Pi 2 running either Ubuntu MATE, or Raspbian.
W. H. Heydt
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Re: Time is "remembered"

Fri Nov 13, 2015 3:18 pm

IF you do a proper shutdown, Raspbian stores the current time in a file and retrieves it when you reboot.
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DougieLawson
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Re: Time is "remembered"

Fri Nov 13, 2015 3:33 pm

W. H. Heydt wrote:IF you do a proper shutdown, Raspbian stores the current time in a file and retrieves it when you reboot.
Not if you get rid of fake-hwclock. Which you MUST do if the RPi has a hardware RTC.
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Kratos
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Re: Time is "remembered"

Sat Nov 14, 2015 1:12 pm

That would explain why the time was 15 minutes slow. Thanks!

Kratos
I have posted mostly with a Pi 2 running either Ubuntu MATE, or Raspbian.
fruit-uk
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Re: Time is "remembered"

Sat Nov 14, 2015 2:03 pm

DougieLawson wrote:
W. H. Heydt wrote:IF you do a proper shutdown, Raspbian stores the current time in a file and retrieves it when you reboot.
Not if you get rid of fake-hwclock. Which you MUST do if the RPi has a hardware RTC.
Not always the case it seems, though I'm sure my other jessie Pi2 is set up like that.

This one, which is on right now, requires fake-hwclock to be installed or I get 1 Jan 1970 entries in syslog shortly after boot.
Otherwise RTC is working perfectly.
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