Re: [chrony-users] Discover when a time sync has been performed

[Ed W <lists@xxxxxxxxxxxxxx>]

On 04/07/2013 19:18, Ignacio Verona Ríos wrote:

2013/7/4 Bill Unruh <unruh@xxxxxxxxxxxxxx>

Does the gps has contiuous power from the car battery or is it plugged into
the Pi for its power? Or is it a gps on your phone?

At boot time a first connection is done to let chrony get the time. I don't have any other reliable time source. GPS is attached to the Pi, as well as the modem. 

Just to repeat a little trick that you can find in gentoo openrc. Here there is a bootscript swclock which tests the mtime of some file and sets the clock to that time.  With a little thought you can arrange for that time to be as close as you like to the "shutdown time".

Now that of course doesn't get you current time, but it does give you something close to monotonic time (ie doesn't step backwards (much)).  ie it gives you a better starting point

Good luck

Ed W

P.S.  Can I recommend the PC Engines Alix boards to those who don't know about them. Multiple network ports, fanless 500Mhz intel x586 processor, USB (some on-board), IDE, RTC - all for ~ $100 ish (ok, more than a Pi)